Analog Devices Inc./Maxim Integrated 的 MAX17262 规格书

规格书反馈/错误

Ordering Information L I :7 , 4. T 74' ml l maxim integrated”

General Description

The MAX17262 is an ultra-low power fuel-gauge IC which

implements the Maxim ModelGauge™ m5 algorithm. The

IC monitors a single-cell battery pack and supports inter-

nal current sensing for up to 3.1A pulse current. The IC

provides best performance for batteries with 100mAhr to

6Ahr capacity.

The ModelGauge m5 EZ makes fuel-gauge implementa-

tion easy by eliminating battery characterization require-

ments and simplifying host software interaction. The

ModelGauge m5 EZ robust algorithm provides tolerance

against battery diversity for most lithium batteries and

applications.

The ModelGauge m5 EZ algorithm combines the short-

term accuracy and linearity of a coulomb counter with the

long-term stability of a voltage-based fuel gauge, along

with temperature compensation to provide industry-lead-

ing fuel-gauge accuracy. The IC automatically compen-

sates for cell-aging, temperature, and discharge rate,

and provides accurate state-of-charge (SOC) in percent-

age (%) and remaining capacity in milliampere-hours

(mAh) over a wide range of operating conditions. As

the battery approaches the critical region near emp-

ty, the ModelGauge m5 algorithm invokes a special cor-

rection mechanism that eliminates any error. The IC pro-

vides accurate estimation of time-to-empty and time-to-

full and provides three methods for reporting the age of

the battery: reduction in capacity, increase in battery re-

sistance, and cycle odometer.

The IC provides precision measurements of current, volt-

age, and temperature. The temperature of the battery

pack is measured using an internal temperature sensor or

external thermistor. A 2-wire I2C interface provides access

to data and control registers. The IC is available in a tiny

lead-free 0.4mm pitch, 1.5mm x 1.5mm, 9-pin wafer-level

package (WLP).

Applications

● Wearables and Smartwatches

● Bluetooth Headset Cases

● Health and Fitness Monitors

● Medical Devices

● Handheld Computers and Terminals

● Home and Building Automation, Sensors

● Toys

Benefits and Features

● ModelGauge m5 EZ

• No Characterization Required for EZ

Performance

• Robust Against Battery Variation

• Eliminates Error Near Empty Voltage

• Eliminates Coulomb-Counter Drift

• Compensates for Age, Current, Temperature

• Does Not Require Empty, Full, or Idle States

● Low 5.2μA Operating Current

● Integrated Internal Current Sensing

• 7mΩ Typical, up to 3.1A Pulse Currents

● Supports Li+ and Variants Including LiFePO4

● Thermistor or ±1°C Internal Temperature

● Dynamic Power Estimates Power Capability During

Discharge

● Time-to-Empty and Time-to-Full Estimation

• Constant Power or Constant Current

● Predicts Remaining Capacity Under Theoretical

Load

● No Calibration Required

● Alert Indicator for Voltage, SOC, Temperature,

Current, and 1% SOC Change

Ordering Information appears at end of data sheet.

Simple Fuel-Gauge Circuit Diagram

SCL

SDA

ALRT

BATT

REG

SYSPWR

SYSGND

SYS

GND

0.47µF

0.1µF

PROTECTION

CIRCUIT

MAX17262

10kΩ

NTC

ModelGauge is a trademark of Maxim Integrated Products, Inc.

Click here for production status of specific part numbers.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

and Internal Current Sensing

EVALUATION KIT AVAILABLE

19-100308; Rev 0; 7/18

TABLE OF CONTENTS

General Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Benefits and Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Simple Fuel-Gauge Circuit Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Absolute Maximum Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

WLP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Typical Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Pin Configuration(s). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Functional Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Detailed Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

ModelGauge m5 EZ Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Application Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Standard Register Formats. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

ModelGauge m5 EZ Configuration Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

DesignCap Register (18h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

VEmpty Register (3Ah). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

ModelCfg Register (DBh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

IChgTerm Register (1Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Config Register (1Dh) and Config2 Register (BBh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

ModelGauge m5 Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

ModelGauge m5 Algorithm Output Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

RepCap Register (05h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

RepSOC Register (06h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

FullCapRep Register (10h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

TTE Register (11h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

TTF Register (20h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Cycles Register (17h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Status Register (00h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Analog Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Voltage Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

VCell Register (09h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

AvgVCell Register (19h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

MaxMinVolt Register (1Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Current Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

and Internal Current Sensing

www.maximintegrated.com Maxim Integrated | 2

TABLE OF CONTENTS (CONTINUED)

Current Register (0Ah). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

AvgCurrent Register (0Bh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

MaxMinCurr Register (1Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Temperature Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Temp Register (08h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

AvgTA Register (16h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

MaxMinTemp Register (1Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

DieTemp Register (034h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Power Register (B1h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

AvgPower Register (B3h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Alert Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

VAlrtTh Register (01h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

TAlrtTh Register (02h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

SAlrtTh Register (03h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

IAlrtTh Register (B4h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Serial Number Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

ModelGauge m5 Memory Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Layout Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

and Internal Current Sensing

www.maximintegrated.com Maxim Integrated | 3

LIST OF FIGURES

Figure 1. ModelGauge m5 EZ Configuration Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 2. ModelGauge m5 Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Figure 3. Current Limit Based On Utilization Patterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 4. MAX17262 Layout Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

and Internal Current Sensing

www.maximintegrated.com Maxim Integrated | 4

LIST OF TABLES

Table 1. ModelGauge m5 EZ Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Table 2. ModelGauge m5 Register Standard Resolutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Table 3. VEmpty (3Ah) Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 4. ModelCFG (DBh) Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 5. Config (1Dh) Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 6. Config2 (BBh) Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 7. Status (00h) Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Table 8. MaxMinVolt (1Bh) Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Table 9. MaxMinCurr (1Ch) Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Table 10. MaxMinTemp (1Ah) Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Table 11. VAlrtTh (01h) Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Table 12. TAlrtTh (02h) Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Table 13. SAlrtTh (03h) Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Table 14. IAlrtTh (B4h) Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Table 15. Serial Number Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Table 16. ModelGauge m5 Register Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

and Internal Current Sensing

www.maximintegrated.com Maxim Integrated | 5

gn and not produclwon Current Measurement 217100168 AQg/Icaﬁon Note 1891 WWW maxlmintegratedcom/Qackages www.maxlmlnlegrated. com/thermalrmona/

Absolute Maximum Ratings

BATT to GND ........................................................... -0.3V to +6V

ALRT to GND ......................................................... -0.3V to +17V

REG to GND.......................................................... -0.3V to +2.2V

TH to GND............................................... -0.3 V to VBATT + 0.3 V

CSN to GND.............................................. -0.3V to VBATT + 0.3V

CSPL to GND ........................................................ -0.3V to +0.3V

SDA, SCL to GND .................................................... -0.3V to +6V

SYS to GND ............................................................. -0.3V to +6V

Operating Temperature Range ............................ -40°C to +85°C

Junction Temperature ...................................................... +150°C

Storage Temperature Range.............................. -55°C to +125°C

Soldering Temperature (reflow)........................................ +260°C

Continuous Source Current for TH ........................................1mA

Continuous Sink Current for SDA, ALRT .............................20mA

Lead Temperature (soldering 10s).................................... +300ºC

Current Limit of Sense Resistor (Continuous current at 100%

utilization (Note 1)).................................................................1.7A

Current Limit of Sense Resistor (Continuous current at 10%

utilization (Note 1)).................................................................2.4A

Current Limit of Sense Resistor (Peak pulsed current, 250ms

maximum pulse width, 10% maximum duty cycle, 1% utilization

(Note 1)).................................................................................3.1A

Note 1: Guaranteed by design and not production tested. Total available utilization is 100,000 hours. Utilization is proportionately

cumulative. See the Current Measurement section for a detailed explanation of the current limit under different utilization

patterns.

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these

or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may

affect device reliability.

Package Information

WLP

Package Code W91G1+2

Outline Number 21-100168

Land Pattern Number Refer to Application Note 1891

Thermal Resistance, Four-Layer Board:

Junction to Ambient (θJA) 83.98ºC/W

Junction to Case (θJC) NA

For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”,

“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing

pertains to the package regardless of RoHS status.

Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board.

For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

and Internal Current Sensing

www.maximintegrated.com Maxim Integrated | 6

(Nels 2 (Nels 9 (Note 9

Electrical Characteristics

(VBATT = 2.3V to 4.9V, TA= -40ºC to +85ºC, typical value for TAis +25ºC. Limits are 100% tested at TA= +25°C. The operating

temperature range and relevant supply voltage range are guaranteed by design and characterization. Specifications marked "GBD" are

guaranteed by design and not production tested.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

POWER SUPPLY

Supply Voltage VBATT (Note 2) 2.3 4.9 V

Shutdown Supply

Current IDD0 TA≤ +50ºC 0.5 0.9 μA

Hibernate Supply

Current IDD1 TA≤ +50ºC, average current 5.2 12 μA

Active Supply Current IDD2 TA≤ +50ºC, average current not including

thermistor measurement current 16 30 μA

Regulation Voltage VREG 1.8 V

Startup Voltage VBATTSU 3 V

ANALOG-TO-DIGITAL CONVERSION

BATT Measurement

Error VGERR

TA= +25ºC -7.5 +7.5 mV

-40ºC ≤ TA≤ +85ºC -20 +20

BATT Measurement

Resolution VLSB 78.125 μV

BATT Measurement

Range VFS 2.3 4.9 V

Sense Resistance RSNS TA= +25°C 7 mΩ

Current Measurement

Offset Error IOERR Zero current, long term average ±1 mA

Current Measurement

Resolution ILSB 0.15625 mA

Current Measurement

Gain Error IGERR (Note 9) ±2.5 % of

Reading

Current Measurement

Error IERR TA≤ +50ºC, 0.5A and 1A (Note 9) -3 +3 % of

Reading

Internal Temperature

Measurement Error TIGERR -40ºC ≤ TA≤ +85ºC ±1 ºC

Internal Temperature

Measurement

Resolution

TILSB 0.00391 ºC

INPUT/OUTPUT

External Thermistance

Resistance

REXT10 Config.R100 = 0 10 kΩ

REXT100 Config.R100 = 1 100

Output Drive Low,

ALRT, SDA VOL IOL = 4mA, VBATT = 2.3V 0.4 V

Input Logic High, ALRT,

SCL, SDA VIH 1.5 V

Input Logic Low, ALRT,

SCL, SDA VIL 0.5 V

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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(Note 3 (Note 4 (Note 5 Note 6 (Note 5 (Note 7 (Note 8

Electrical Characteristics (continued)

(VBATT = 2.3V to 4.9V, TA= -40ºC to +85ºC, typical value for TAis +25ºC. Limits are 100% tested at TA= +25°C. The operating

temperature range and relevant supply voltage range are guaranteed by design and characterization. Specifications marked "GBD" are

guaranteed by design and not production tested.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Battery-Detach

Detection Threshold VDET Measured as a fraction of VBATT on TH

rising 91 96.2 99 %

Battery-Detach

Detection Threshold

Hysteresis

VDET-HYS Measured as a fraction of VBATT on TH

falling 1 %

Battery-Detach

Comparator Delay tTOFF TH step from 70% to 100% of VBATT

(Alrtp = 0, EnAIN = 1, FTHRM = 1) 100 μs

LEAKAGE

Leakage Current, CSN,

ALRT ILEAK VALRT < 15V -1 +1 μA

Input Pulldown Current IPD VSDA = 0.4V, VSCL = 0.4V 0.05 0.2 0.4 μA

2-WIRE INTERFACE

SCL Clock Frequency fSCL (Note 3) 0 400 kHz

Bus Free Time Between

a STOP and START

Condition

tBUF 1.3 μs

Hold Time (Repeated)

START Condition tHD:STA (Note 4) 0.6 μs

Low Period of SCL

Clock tLOW 1.3 μs

High Period of SCL

Clock tHIGH 0.6 μs

Setup Time for a

Repeated START

Condition

tSU:STA 0.6 μs

Data Hold Time tHD:DAT (Note 5,Note 6) 0 0.9 μs

Data Setup Time tSU:DAT (Note 5) 100 ns

Rise Time of Both SDA

and SCL Signals tR5 300 ns

Fall Time of Both SDA

and SCL Signals tF5 300 ns

Setup Time for STOP

Condition tSU:STO 0.6 μs

Spike Pulse Width

Suppressed by Input

Filter

tSP (Note 7) 50 ns

Capacitive Load for

Each Bus Line CB(Note 8) 400 pF

SCL, SDA Input

Capacitance CBIN 6 pF

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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Electrical Characteristics (continued)

(VBATT = 2.3V to 4.9V, TA= -40ºC to +85ºC, typical value for TAis +25ºC. Limits are 100% tested at TA= +25°C. The operating

temperature range and relevant supply voltage range are guaranteed by design and characterization. Specifications marked "GBD" are

guaranteed by design and not production tested.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

TIMING

Time-Base Accuracy tERR TA= +25°C -1 +1 %

TH Precharge Time tPRE 8.48 ms

Note 2: All voltages are referenced to GND.

Note 3: Timing must be fast enough to prevent the IC from entering shutdown mode due to bus low for a period greater than the

shutdown timer setting.

Note 4: fSCL must meet the minimum clock low time plus the rise/fall times.

Note 5: The maximum tHD:DAT has only to be met if the device does not stretch the low period (tLOW) of the SCL signal.

Note 6: This device internally provides a hold time of at least 100ns for the SDA signal (refer to the minimum VIH of the SCL signal)

to bridge the undefined region of the falling edge of SCL.

Note 7: Filters on SDA and SCL suppress noise spikes at the input buffers and delay the sampling instant.

Note 8: CBrepresents total capacitance of one bus line in pF.

Note 9: Guaranteed by design and not production tested.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

and Internal Current Sensing

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ACIIVE cuRnEm SHUTDDWN CURRENY HIBERNAIE CURRENI Vi. SUPPLY VOLYAGE VI SUPPLY VOLTAGE V! SUPPLY VOLTAGE x w ‘ ‘0 '0 N 29 ~5M H m-c 5 ‘5 3—” i na 4’ g S r/‘M _,_. E 4’ E f .0 '2‘ 3 rare I] 1 ' z 5 n a =4 J Q , 2 3 o . 2 a A , Z 3 ‘ vomE M vow 1A5: M vow“ M ms vsupamuna AND minwsToR . 5“" "DUN“ “’5 ERROR K V cunnsm MEASUREMENY ERROR MEASUREMEMY [anon a » m w .0 w we own 5 ' 6 f 5 S \ 7 nzmma 5 WW 2 m 2: \ 2 o W 3; a ’ “ 2 a ‘ w a , 4/ “ ,a-c msxw s 75 75 4n , u 32 A La 724nm mm a mm mm ‘5 m 35 a; 35 voL'AoE m ,muxs «m CHARGE mu nIscHARGE («2mm Hot DISCHARGE («m1 cow DISCHARGE (we) .9 we a 92 s .3 mm: mm: REPSOC , V a a 3 7a A g g as a , 5 § 3 50 F E g E ,2 E 23 4a 5 3‘ 5 E 4 3 30 i g A 20 REFEREVéE ¢ ,0 5:: C a 15 2t 32 r ‘ ; 5 12 ‘3 2b a E ‘2 ’B 26 HME [HOURS] nms wouw ’wE Moms)

Typical Operating Characteristics

(TA= +25°C, unless otherwise noted.)

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

and Internal Current Sensing

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Typical Operating Characteristics (continued)

(TA= +25°C, unless otherwise noted.)

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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Pin Configuration(s)

SCL

BATT

MAX17262

WLP

TOP VIEW

(BUMP SIDE DOWN)

SYS

SDA

ALRT

REG GND

Pin Descriptions

PIN NAME FUNCTION

A3 NC No Connection.

A1 TH Thermistor Input. Connect a thermistor from TH to GND. TH also provides battery insertion/removal

detection. Connect to BATT if not used.

B1 SCL Serial Clock Input. 2-wire clock line. Input only. SCL has an internal pulldown (IPD) for sensing

disconnection.

C1 SDA Serial Data Input/Output. 2-wire data line. Open-drain output driver. SDA has an internal pulldown (IPD)

for sensing disconnection.

B3 SYS System Power. Connect to system load.

A2 BATT IC Power Supply and Battery Voltage Sense Input. Connect to the positive terminal of a battery

cell. Bypass with a 0.1μF capacitor to GND.

C3 GND IC Ground.

C2 REG Internal 1.8V Regulator Output. Bypass with an external 0.47μF capacitor to GND. Do not load

externally.

B2 ALRT Alert Output. The ALRT pin is an open-drain active-low output which indicates fuel-gauge alerts. Connect

to GND if not used.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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BATT ||+ ‘H—H—O ALRT SYSPWR SDA SCL REG 'IHF

Functional Diagram

ModelGauge m5 ModelGauge m5

CORECORE

SCL

SDA

ALRT

BATT

REG

SYSPWRSYSPWR

SYSGNDSYSGND

1.8V LDO

OUT

MAX17262MAX17262

SYS

MUX

BATT

GND

ADC I2C

INTERFACE

32kHz

OSCILLATOR

INTERNAL

TEMPERATURE

SENSOR

THRM

ENABLE

INTERNAL

PULLUP

10kΩ/

100kΩ

NTC

PROTECTION

CIRCUIT

0.1µF

0.47µF

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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Serial Number Feature User Guide 6597: MAX1726X Made/(Sauce m5 EZ User Guide Table 1 Frgure1

Detailed Description

The MAX17262 is an ultra-low power fuel gauge IC which implements the Maxim ModelGauge m5 EZ algorithm. The IC

measures voltage, current, and temperature accurately to produce fuel gauge results. The ModelGauge m5 EZ robust

algorithm provides tolerance against battery diversity. This additional robustness enables simpler implementation for

most applications and batteries by avoiding time-consuming battery characterization. The IC features internal current

measurement for up to 3.1A pulse currents. The IC provides best performance for batteries with 100mAhr to 6Ahr

capacity.

The ModelGauge m5 algorithm combines the short-term accuracy and linearity of a coulomb-counter with the long-term

stability of a voltage-based fuel gauge, along with temperature compensation to provide industry-leading fuel-gauge

accuracy. The IC automatically compensates for aging, temperature, and discharge rate and provides accurate state-

of-charge (SOC) in percentage (%) and remaining capacity in milliampere-hours (mAh) over a wide range of operating

conditions. Fuel-gauge error always converges to 0% as the cell approaches empty.

The IC has a register set that is compatible with Intel's DBPT v2 dynamic power standard. This allows the system

designer to safely estimate the maximum allowed CPU turbo-boost power level in complex power conditions. The IC

provides accurate estimation of time-to-empty and time-to-full and provides three methods for reporting the age of the

battery: reduction in capacity, increase in battery resistance, and cycle odometer.

The IC contains a unique serial number. It can be used for cloud-based authentication. See the Serial Number

Feature section for more information.

Communication to the host occurs over standard I2C interface. For information about I2C communication, refer

to the User Guide 6597: MAX1726x ModelGauge m5 EZ User Guide.

ModelGauge m5 EZ Performance

ModelGauge m5 EZ performance provides plug-and-play operation when the IC is connected to most lithium batteries.

While the IC can be custom tuned to the application's specific battery through a characterization process for ideal

performance, the IC has the ability to provide good performance for most applications with no custom characterization

required. Table 1 and Figure 1 show the performance of the ModelGauge m5 algorithm in applications using ModelGauge

m5 EZ configuration.

The ModelGauge m5 EZ provides good performance for most cell types. For some chemistries, such as lithium-iron-

phosphate (LiFePO4) and Panasonic NCR/NCA series cells, it is suggested that the customer request a custom model

from Maxim for best performance.

For even better fuel-gauging accuracy than ModelGauge m5 EZ, contact Maxim for information regarding cell

characterization.

Table 1. ModelGauge m5 EZ Performance

DESCRIPTION AFTER FIRST CYCLE* (%) AFTER SECOND CYCLE* (%)

Tests with less than 3% error 95 97

Tests with less than 5% error 98.7 99

Tests with less than 10% error 100 100

*Test conditions: +20°C and +40°C, run time of > 3 hours.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

and Internal Current Sensing

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User Guide 6597: MAX1 726x ModelGauue m5 EZ User Guide User Guide 6595: MAX 1 726x Soﬁware Imnlementation Guide Table 2

TEST CONDITIONS:

· 300+ DIFFERENT BATTERIES

· 3000+ DISCHARGES

· BETWEEN +20ºC TO +40ºC

· RUN TIME OF > 3 HOURS

· AFTER FIRST CYCLE

ModelGauge m5 EZ CONFIGURATION PERFORMANCEModelGauge m5 EZ CONFIGURATION PERFORMANCE

PERCENTILE OF TESTS (%)

WORST CASE ERROR DURING DISCHARGE (%)

10%

20%

30%

40%

50%

60%

1 2 3 4 5 6 7 8 9 10

Figure 1. ModelGauge m5 EZ Configuration Performance

Application Notes

Refer to the following application notes for additional reference material:

●User Guide 6597: MAX1726x ModelGauge m5 EZ User Guide

• Documents full register set

• More details about ModelGauge m5 algorithm

• Discusses additional applications

●User Guide 6595: MAX1726x Software Implementation Guide

• Guidelines for software drivers including example code

Standard Register Formats

Unless otherwise stated during a given register's description, all IC registers follow the same format depending on the

type of register. See Table 2 for the resolution and range of any register described hereafter.

Table 2. ModelGauge m5 Register Standard Resolutions

TYPE

LSb

SIZE

MINIMUM

VALUE

MAXIMUM

VALUE NOTES

Capacity 0.5mAh 0.0mAh 32767.5mAh

Percentage 1/256% 0.0% 255.9961% 1% LSb when reading only the upper byte.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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MAX 1 726x Software lmQ/emenlation Guide Table 3

Table 2. ModelGauge m5 Register Standard Resolutions (continued)

TYPE

LSb

SIZE

MINIMUM

VALUE

MAXIMUM

VALUE NOTES

Voltage 1.25mV/

16 0.0V 5.11992V

Current 156.25μA -5.12A 5.12A Signed two's-complement format.

Temperature 1/256°C -128.0°C 127.996°C Signed two's-complement format. 1°C LSb when reading only the

upper byte.

Resistance 1/4096Ω 0.0Ω 15.99976Ω

Time 5.625s 0.0s 102.3984h

Special Format details are included with the register description.

ModelGauge m5 EZ Configuration Registers

The following registers are inputs to the ModelGauge m5 algorithm and store characterization information for the

application cells as well as important application specific parameters. They are described briefly here.

Only the following information is required for configuring ModelGauge m5 EZ:

● Label Capacity—DesignCap

● Empty Voltage—VEmpty

● Charge Termination Current—ICHGTerm

Refer to the MAX1726x Software Implementation Guide for more details on how to initialize the fuel gauge.

DesignCap Register (18h)

Initial value: 0x0BB8

The DesignCap register holds the nominal capacity of the cell. The IC provides best performance for batteries with

100mAhr to 6Ahr capacity.

VEmpty Register (3Ah)

Initial Value: 0xA561 (3.3V/3.88V)

The VEmpty register sets thresholds related to empty detection during operation. Table 3 shows the register format.

Table 3. VEmpty (3Ah) Format

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

VE VR

VE: Empty voltage target, during load. The fuel gauge provides capacity and percentage relative to the empty voltage

target, eventually declaring 0% at VE. A 10mV resolution gives a 0V to 5.11V range. This value defaults to 3.3V after

reset.

VR: Recovery voltage. Sets the voltage level for clearing empty detection. Once the cell voltage rises above this point,

empty voltage detection is reenabled. A 40mV resolution gives a 0V to 5.08V range. This value defaults to 3.88V, which

is recommended for most applications.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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Tab‘e 4 User Guide 6597: MAX1726X Made/Gauae m5 EZ User Guide Table 5 Table 6

ModelCfg Register (DBh)

The ModelCFG register controls basic options of the EZ algorithm. Table 4 shows the register format.

Table 4. ModelCFG (DBh) Format

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

Refresh 0 R100 0 0 VChg 0 0 ModelID 0 1 0 0

Refresh: Set Refresh to 1 to command the model reload. After completion the MAX17262 clears Refresh to 0.

R100: if using 100kΩ NTC, set R100 = 1; if using 10kΩ NTC, set R100 = 0.

ModelID: Choose from one of the following Lithium models. For the majority of batteries, use ModelID = 0.

ModelID = 0: Use for most lithium cobalt-oxide variants (a large majority of lithium in the market-place). Supported by EZ

without characterization.

ModelID = 2: Use for lithium NCR or NCA cells such as Panasonic. Custom characterization is recommended in this

case.

ModelID = 6: Use for lithium iron-phosphate (LiFePO4). Custom characterization is recommended in this case.

VChg: Set VChg to 1 for charge voltage higher than 4.25V (4.3V–4.4V). Set VChg to 0 for 4.2V charge voltage.

IChgTerm Register (1Eh)

Initial Value: 0x0640 (500mA)

The IChgTerm register allows the device to detect when charge termination has occurred. Program IChgTerm to the

exact charge termination current used in the application.

Refer to the End-of-Charge Detection section of the User Guide 6597: MAX1726x ModelGauge m5 EZ User Guide for

more details.

Config Register (1Dh) and Config2 Register (BBh)

Initial Value: 0x2210 for Config, 0x3658 for Config2

The Config registers hold all shutdown enable, alert enable, and temperature enable control bits. Writing a bit location

enables the corresponding function within one task period. (One task period is 175ms in active mode, and 5.6 seconds

in hibernate mode by default.) Table 5 and Table 6 show the register formats.

Table 5. Config (1Dh) Format

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

TSel SS TS VS IS THSH Ten Tex SHDN COMMSH 0 ETHRM FTHRM Aen Bei Ber

Table 6. Config2 (BBh) Format

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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User Guide 6597: MAX 1 726x Mode/Gauae m5 EZ User Guide

Table 6. Config2 (BBh) Format (continued)

0 0 AtRateEn DPEn POWR dSOCen TAlrtEn LDMdl 1 DRCfg CPMode 0

0: Bit must be written 0. Do not write 1.

1: Bit must be written 1. Do not write 0.

TSEL: Temperature sensor select. Set to 0 to use internal die temperature. Set to 1 to use temperature information from

thermistor. ETHRM bit must be set to 1 when TSel is 1.

SS: SOC ALRT Sticky. When SS = 1, SOC alerts can only be cleared through software. When SS = 0, SOC alerts are

cleared automatically when the threshold is no longer exceeded.

TS: Temperature ALRT Sticky. When TS = 1, temperature alerts can only be cleared through software. When TS = 0,

temperature alerts are cleared automatically when the threshold is no longer exceeded.

VS: Voltage ALRT Sticky. When VS = 1, voltage alerts can only be cleared through software. When VS = 0, voltage alerts

are cleared automatically when the threshold is no longer exceeded.

IS: Current ALRT Sticky. When IS = 1, current alerts can only be cleared through software. When IS = 0, current alerts

are cleared automatically when the threshold is no longer exceeded.

THSH: TH Pin Shutdown. Set to 1 to enable device shutdown when the IC is mounted host-side and the battery is

removed. The IC enters shutdown if the TH pin remains high (VTH > VBATT - VDET) for longer than the timeout of the

ShdnTimer register. This also configures the device to wake up when TH is pulled low with a thermistor on-cell insertion.

Note that if COMMSH and AINSH are both set to 0, the device wakes up on any edge of SDA.

Ten: Enable Temperature Channel. Set to 1 and set ETHRM or FTHRM to 1 to enable temperature measurement.

Tex: Temperature External. When set to 1, the fuel gauge requires external temperature measurements to be written

from the host. When set to 0, the ICs own measurements are used instead.

SHDN: Shutdown. Write this bit to logic 1 to force a shutdown of the device after timeout of the ShdnTimer register

(default 45s delay). SHDN is reset to 0 at power-up and upon exiting shutdown mode. In order to command shutdown

within 45 seconds, first write HibCFG = 0x0000 to enter active mode.

COMMSH: Communication Shutdown. Set to logic 1 to force the device to enter shutdown mode if both SDA and SCL

are held low for more than timeout of the ShdnTimer register. This also configures the device to wake up on a rising edge

of any communication. Note that if COMMSH and THSH are both set to 0, the device wakes up on any edge of SDA.

Refer to the User Guide 6597: MAX1726x ModelGauge m5 EZ User Guide for details.

ETHRM: Enable Thermistor. Set to logic 1 to enable the TH pin measurement.

FTHRM: Force Thermistor Bias Switch. This allows the host to control the bias of the thermistor switch or enable

fast detection of battery removal. Set FTHRM = 1 to always enable the thermistor bias switch. With a standard 10kΩ

thermistor, this adds an additional ~200μA to the current drain of the circuit.

Aen: Enable alert on fuel-gauge outputs. When Aen = 1, any violation of the alert threshold register values by

temperature, voltage, current, or SOC triggers an alert. This bit affects the ALRT pin operation only. The Smx, Smn, Tmx,

Tmn, Vmx, Vmn, Imx, and Imn bits of the Status register (000h) are not disabled.

Bei: Enable alert on battery insertion when the IC is mounted host-side. When Bei = 1, a battery-insertion condition, as

detected by the TH pin voltage, triggers an alert.

Ber: Enable alert on battery removal when the IC is mounted host-side. When Ber = 1, a battery-removal condition, as

detected by the TH pin voltage, triggers an alert.

AtRateEn: AtRate enable. When this bit is set to 0, AtRate calculations are disabled and registers AtQResidual/AtTTE/

AtAvSOC/AtAvCap can be used as general purpose memory.

DPEn: Dynamic power enable. When this bit is set to 0, Dynamic Power calculations are disabled and registers

MaxPeakPower/SusPeakPower/MPPCurrent/SPPCurrent can be used as general purpose memory.

POWR: Sets the time constant for the AvgPower register. The default POR value of 0100b gives a time constant of

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

and Internal Current Sensing

www.maximintegrated.com Maxim Integrated | 18

ngure 2

11.25s. The equation setting the period is:

AvgPower time constant = 45s x 2(POWR-6)

dSOCen: SOC Change Alert Enable. Set this bit to 1 to enable alert output with the Status.dSOCi bit function. Write this

bit to 0 to disable alert output with the Status. dSOCi bit. This bit is set to 0 at power-up.

TAlrten: Temperature Alert Enable. Set this bit to 1 to enable temperature based alerts. Write this bit to 0 to disable

temperature alerts. This bit is set to 1 at power-up.

LDMdl: Host sets this bit to 1 in order to initiate firmware to finish processing a newly loaded model. Firmware clears this

bit to zero to indicate that model loading is finished.

DRCfg: Deep relax time configuration. 00 for 0.8 to 1.6 hours, 01 for 1.6 to 3.2 hours, 10 for 3.2 to 6.4 hours and 11 for

6.4 to 12.8 hours.

CPMode: Constant-power mode. Set to 1 to enable constant-power mode. If it is set to 0, AtRate/AvgCurrent is used for

(At)TTE/(At)QResidual/(At)AvSOC/(At)AvCap. If it is set to 1, AtRate/AvgCurrent x AvgVCell

(AvgVCell + VEmpty)

2is used for those

calculations

ModelGauge m5 Algorithm

Classical coulomb-counter-based fuel gauges have excellent linearity and short-term performance. However, they suffer

from drift due to the accumulation of the offset error in the current-sense measurement. Although the offset error is often

very small, it cannot be eliminated. It causes the reported capacity error to increase over time and requires periodic

corrections. Corrections are traditionally performed at full or empty. Some other systems also use the relaxed battery

voltage to perform corrections. These systems determine the true state-of-charge (SOC) based on the battery voltage

after a long time of no current flow. Both have the same limitation: if the correction condition is not observed over time in

the actual application, the error in the system is boundless. The performance of classic coulomb counters is dominated by

the accuracy of such corrections. Voltage measurement based SOC estimation has accuracy limitations due to imperfect

cell modeling, but does not accumulate offset error over time.

The IC includes an advanced voltage fuel gauge (VFG) that estimates open-circuit voltage (OCV), even during current

flow, and simulates the nonlinear internal dynamics of a Li+ battery to determine the SOC with improved accuracy. The

model considers the time effects of a battery caused by the chemical reactions and impedance in the battery to determine

SOC. This SOC estimation does not accumulate offset error over time. The IC performs a smart empty compensation

algorithm that automatically compensates for the effect of temperature condition and load condition to provide accurate

state-of-charge information. The converge-to-empty function eliminates error toward empty state. The IC learns battery

capacity over time automatically to improve long-term performance. The age information of the battery is available in the

output registers.

The ModelGauge m5 algorithm combines a high-accuracy coulomb counter with a VFG. See Figure 2. The

complementary combined result eliminates the weaknesses of both the coulomb counter and the VFG while providing

the strengths of both. A mixing algorithm weighs and combines the VFG capacity with the coulomb counter and weighs

each result so that both are used optimally to determine the battery state. In this way, the VFG capacity result is used to

continuously make small adjustments to the battery state, cancelling the coulomb-counter drift.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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www.maximintegrated.com Maxim Integrated | 19

CAPACITY

%SOC CHANGE Q CHANGE

MICROCORRECTIONS

FULL, EMPTY, AND

STANDBY-STATE

DETECTION UNNECESSARY

ModelGauge

ALGORITHM

RSENSE

CURRENT

COULOMB

COUNTER

INTEGRATOR

Figure 2. ModelGauge m5 Algorithm

The ModelGauge m5 algorithm uses this battery state information and accounts for temperature, battery current, age,

and application parameters to determine the remaining capacity available to the system. As the battery approaches the

critical region near empty, the ModelGauge m5 algorithm invokes a special error correction mechanism that eliminates

any error.

The ModelGauge m5 algorithm continually adapts to the cell and application through independent learning routines. As

the cell ages, its change in capacity is monitored and updated and the voltage-fuel-gauge dynamics adapt based on cell-

voltage behavior in the application.

ModelGauge m5 Algorithm Output Registers

The following registers are outputs from the ModelGauge m5 algorithm. The values in these registers become valid

351ms after the IC is configured.

RepCap Register (05h)

RepCap or reported remaining capacity in mAh. The ModelGauge m5 algorithm prevents remaining capacity from making

a sudden jump during load change conditions.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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Tab‘e 7

RepSOC Register (06h)

RepSOC is the reported state-of-charge percentage output for use by the application user interface.

FullCapRep Register (10h)

This register reports the full capacity that goes with RepCap, generally used for reporting to the user. A new full-capacity

value is calculated at the end of every charge cycle in the application.

TTE Register (11h)

The TTE register holds the estimated time to empty for the application under present temperature and load conditions.

TTE register is only valid when current register is negative.

TTF Register (20h)

The TTF register holds the estimated time to full for the application under present conditions. The TTF value is

determined by learning the constant current and constant voltage portions of the charge cycle based on experience of

prior charge cycles. Time-to-full is then estimated by comparing the present charge current to the charge termination

current. Operation of the TTF register assumes all charge profiles are consistent in the application. The TTF register is

only valid when the current register is positive.

Cycles Register (17h)

The Cycles register maintains a total count of the number of charge/discharge cycles of the cell. The result is stored

as a fraction of a full cycle. For example, a full charge/discharge cycle results in the Cycles register incrementing by

100%. The Cycles register accumulates fractional or whole cycles. For example, if a battery is cycled 10% x 10 times,

then it is equivalent to 100% of one cycle. The Cycles register has a full range of 0 to 655.35 cycles with a 1% LSb.

Status Register (00h)

Initial Value: 0x8082

The Status register maintains all flags related to alert thresholds and battery insertion or removal. Table 7 shows the

Status register format.

Table 7. Status (00h) Format

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

Br Smx Tmx Vmx Bi Smn Tmn Vmn dSOCi Imx X X Bst Imn POR X

POR (Power-On Reset): This bit is set to 1 when the device detects that a software or hardware POR event has

occurred. This bit must be cleared by system software to detect the next POR event. POR is set to 1 at power-up.

Imn and Imx (Minimum/Maximum Current-Alert Threshold Exceeded): These bits are set to 1 whenever a Current

system software to detect the next event. See Config.IS bit description. Imn and Imx are cleared to 0 at power-up.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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Tab‘e 8

Vmn and Vmx (Minimum/Maximum Voltage-Alert Threshold Exceeded): These bits are set to 1 whenever a VCell

system software to detect the next event. See Config.VS bit description. Vmn and Vmx are cleared to 0 at power-up.

Tmn and Tmx (Minimum/Maximum Temperature-Alert Threshold Exceeded): These bits are set to 1 whenever a

Temperature register reading is below (Tmn) or above (Tmx) the TAlrtTh thresholds. These bits may or may not need to

be cleared by system software to detect the next event. See Config.TS bit description. Tmn and Tmx are cleared to 0 at

power-up.

Smn and Smx (Minimum/Maximum SOC-Alert Threshold Exceeded): These bits are set to 1 whenever SOC is below

(Smn) or above (Smx) the SAlrtTh thresholds. These bits may or may not need to be cleared by system software to

detect the next event. See Config.SS description. Smn and Smx are cleared to 0 at power-up.

Bst (Battery Status): Useful when the IC is used in a host-side application. This bit is set to 0 when a battery is present

in the system, and set to 1 when the battery is absent. Bst is set to 0 at power-up.

dSOCi (State-of-Charge 1% Change Alert): This is set to 1 whenever the RepSOC register crosses an integer

percentage boundary such as 50.0%, 51.0%, etc. Must be cleared by host software. dSOCi is set to 1 at power-up.

Bi (Battery Insertion): Useful when the IC is used in a host-side application. This bit is set to 1 when the device detects

that a battery has been inserted into the system by monitoring the TH pin. This bit must be cleared by system software

to detect the next insertion event. Bi is set to 0 at power-up.

Br (Battery Removal): Useful when the IC is used in a host-side application. This bit is set to 1 when the system detects

that a battery has been removed from the system. This bit must be cleared by system software to detect the next removal

event. Br is set to 1 at power-up.

X (Don’t Care): This bit is undefined and can be logic 0 or 1.

Analog Measurements

The IC monitors voltage, current, and temperature. This information is provided to the fuel-gauge algorithm to predict cell

capacity and also made available to the user.

Voltage Measurement

VCell Register (09h)

VCell reports the voltage measured between BATT and GND.

AvgVCell Register (19h)

The AvgVCell register reports an average of the VCell register readings.

MaxMinVolt Register (1Bh)

Initial Value: 0x00FF

The MaxMinVolt register maintains the maximum and minimum of VCell register values since device reset. At power-up,

the maximum voltage value is set to 00h (the minimum) and the minimum voltage value is set to FFh (the maximum).

Therefore, both values are changed to the voltage register reading after the first update. Host software can reset this

values with a 20mV resolution. Table 8 shows the register format.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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Absolute Maximum Ratings Figure 3

Table 8. MaxMinVolt (1Bh) Format

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

MaxVCELL MinVCELL

MaxVCELL: Maximum VCell register reading

MinVCELL: Minimum VCell register reading

Current Measurement

The MAX17262 monitors the current flow through the battery by measuring the voltage across the internal current

sensing element. The IC is precalibrated for current-measurement accuracy in Maxim's factory. Additionally, the IC

maintains a record of the minimum and maximum current measured by the IC and an average current.

The maximum current constraints listed in the Absolute Maximum Ratings section should be followed to ensure the

100,000 hours lifetime of the sensing element. In general, the root mean square of current over whole lifetime should

below 1.7A, with additional limitation on peak value based on utilization. If the device utilization is 100% (charges or

discharges at highest allowable current level without stopping), then the maximum DC current rating is 1.7A. If the device

utilization is 10%, then the maximum DC current allowed is 2.4A. For example, it spends 10% of its time charging, and

the remaining 90% resting or discharging, then it can be allowed 2.4A charge current, but discharge currents should be

below 1.6A. For Pulse current case, if the utilization of the current pulse is 1% of whole lifetime, then the peak pulse

current allowed with 250ms pulse width and 10% duty cycle is 3.1A. The utilization patterns are visualized in Figure 3.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

and Internal Current Sensing

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CURRENT IA) 3.50 3.017 2.50 2.0a 154: we CURRENT LIMIT BASED ON UTILIZATION PATIERNS — erAm 5mg —1n~;. LmuzAuuM cuxngm — 1% unuzmou cumur \ ZAAUM .7A CONTINUOU m \ wwrm 20 an 40 so 5a 70 an 911 TIME (SI mu Absolute Maximum Ratings

3.1A PULSED CURRENT, 10% DUTY,

1% OF LIFETIME

1.6A LIMIT FOR 90% OF LIFETIME

2.4A LIMIT 10% OF LIFETIME

1.7A CONTINUOUS CURRENT LIMIT

1.68A CONTINUOUS CURRENT

IN THE REST 99% OF LIFETIME

Figure 3. Current Limit Based On Utilization Patterns

Current Register (0Ah)

The MAX17262 uses internal current sensing to monitor the current through the SYS pin. The measurement value

is stored in two's-complement format. Measurement that exceeds maximum and minimum current range is stored as

maximum and minimum value. The current register has a LSB value of 156.25μA, a register scale range of ± 5.12 A, and

an allowable measurement range as described in the Absolute Maximum Ratings.

AvgCurrent Register (0Bh)

The AvgCurrent register reports an average of Current register readings.

MaxMinCurr Register (1Ch)

Initial Value: 0x807F

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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Tab‘e 9 User Guide 6597: MAX 1 726x Mode/Gauge m5 EZ User Guide Table 10

The MaxMinCurr register maintains the maximum and minimum Current register values since the last IC reset or until

cleared by host software. At power-up, the maximum current value is set to 80h (most negative) and the minimum current

value is set to 7Fh (most positive). Therefore, both values are changed to the Current register reading after the first

update. Host software can reset this register by writing it to its power-up value of 0x807F. The maximum and minimum

currents are each stored as two’s complement 8-bit values with 160mA resolution. Table 9 shows the register format.

Table 9. MaxMinCurr (1Ch) Format

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

MaxCurrent MinCurrent

MaxCurrent: Maximum Current register reading

MinCurrent: Minimum Current register reading

Temperature Measurement

The IC can be configured to measure its own internal die temperature or an external NTC thermistor.

Set Config.TSEL = 0 (default) to enable die temperature measurement. Set Config.TSEL = 1 to enable thermistor

measurement.

Thermistor conversions are initiated by periodically connecting the TH and BATT pins internally. Measurement results of

TH pin are compared to the voltage of the BATT pin and converted to a ratiometric value from 0% to 100%. The active

pullup is disabled when temperature measurements are complete. This reduces the current consumption.

The ratiometric results are converted to temperature using the temperature gain (TGain), temperature offset (TOff), and

temperature curve (Curve) register values. Internal die temperature measurements are factory calibrated and are not

affected by TGain, TOff, and Curve register settings. Refer to the User Guide 6597: MAX1726x ModelGauge m5 EZ

User Guide for more details. Additionally, the IC maintains a record of the minimum and maximum temperature measured

and an average temperature.

Temp Register (08h)

The Temp register provides the temperature measured by the thermistor or die temperature based on the Config register

setting.

AvgTA Register (16h)

The AvgTA register reports an average of the readings from the Temp register.

MaxMinTemp Register (1Ah)

Initial Value: 0x807F

The MaxMinTemp register maintains the maximum and minimum Temp register (08h) values since the last fuel-gauge

reset or until cleared by host software. At power-up, the maximum value is set to 0x80 (most negative) and the minimum

value is set to 0x7F (most positive). Therefore, both values are changed to the Temp register reading after the first

update. Host software can reset this register by writing it to its power-up value of 0x807F. The maximum and minimum

temperatures are each stored as two’s complement 8-bit values with 1°C resolution. Table 10 shows the format of the

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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Table 1 1

Table 10. MaxMinTemp (1Ah) Format

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

MaxTemperature MinTemperature

MaxTemperature: Maximum Temp register reading

MinTemperature: Minimum Temp register reading

DieTemp Register (034h)

The DieTemp register provides the internal die temperature measurement. If Config.TSel = 0, DieTemp and Temp

registers have the value of the die temperature.

Power Register (B1h)

Instant power calculation from immediate current and voltage. The LSB is 1.6mW.

AvgPower Register (B3h)

Filtered average power from the Power register. LSB is 1.6mW.

Alert Function

The Alert Threshold registers allow interrupts to be generated by detecting a high or low voltage, current, temperature,

or state-of-charge. Interrupts are generated on the ALRT pin open-drain output driver. An external pullup is required to

generate a logic-high signal. Alerts can be triggered by any of the following conditions:

• Battery removal: (VTH > VBATT – VDET) and battery removal detection enabled (Ber = 1).

• Battery insertion: (VTH < VBATT – VDET-HYS) and battery insertion detection enabled (Bei = 1).

• Over/undervoltage: VAlrtTr register threshold violation (upper or lower) and alerts enabled (Aen = 1).

• Over/undertemperature: TAlrtTr register threshold violation (upper or lower) and alerts enabled (Aen = 1).

• Over/undercurrent: IAlrtTr register threshold violation (upper or lower) and alerts enabled (Aen = 1).

• Over/under SOC: SAlrtTr register threshold violation (upper or lower) and alerts enabled (Aen = 1).

• 1% SOC change: RepSOC register bit d8 (1% bit) changed (dSOCen = 1).

To prevent false interrupts, the threshold registers should be initialized before setting the Aen bit. Alerts generated

by battery insertion or removal can only be reset by clearing the corresponding bit in the Status (00h) register. Alerts

generated by a threshold-level violation can be configured to be cleared only by software, or cleared automatically when

the threshold level is no longer violated. See the Config (1Dh) and Config2 (BBh) register descriptions for details of the

alert function configuration.

VAlrtTh Register (01h)

Initial Value: 0xFF00 (Disabled)

The VAlrtTh register shown in Table 11 sets upper and lower limits that generate an alert if exceeded by the VCell register

value. The upper 8 bits set the maximum value and the lower 8 bits set the minimum value. Interrupt threshold limits are

selectable with 20mV resolution over the full operating range of the VCell register.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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(Table 12 (Table 13 (Table 14

Table 11. VAlrtTh (01h) Format

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

VMAX VMIN

VMAX: Maximum voltage reading. An alert is generated if the VCell register reading exceeds this value.

VMIN: Minimum voltage reading. An alert is generated if the VCell register reading falls below this value.

TAlrtTh Register (02h)

Initial Value: 0x7F80 (Disabled)

The TAlrtTh register (Table 12) sets upper and lower limits that generate an alert if exceeded by the Temp register value.

The upper 8 bits set the maximum value and the lower 8 bits set the minimum value. Interrupt threshold limits are stored

in two’s-complement format with 1°C resolution over the full operating range of the Temp register.

Table 12. TAlrtTh (02h) Format

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

TMAX TMIN

TMAX: Maximum temperature reading. An alert is generated if the Temp register reading exceeds this value.

TMIN: Minimum temperature reading. An alert is generated if the Temp register reading falls below this value.

SAlrtTh Register (03h)

Initial Value: 0xFF00 (Disabled)

The SAlrtTh register shown (Table 13) sets upper and lower limits that generate an alert if exceeded by RepSOC. The

upper 8 bits set the maximum value and the lower 8 bits set the minimum value. Interrupt threshold limits are configurable

with 1% resolution over the full operating range of the RepSOC register.

Table 13. SAlrtTh (03h) Format

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

SMAX SMIN

SMAX: Maximum state-of-charge threshold. An alert is generated if the RepSOC register exceeds this value.

SMIN: Minimum state-of-charge threshold. An alert is generated if the RepSOC register falls below this value.

IAlrtTh Register (B4h)

Initial Value: 0x7F80 (Disabled)

The IAlrtTh register (Table 14) sets upper and lower limits that generate an alert if exceeded by the Current register

value. The upper 8 bits set the maximum value and the lower 8 bits set the minimum value. Interrupt threshold limits are

selectable with 80mA resolution over the full operating range of the Current register.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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Mode/Gauge m5 EZ Algorithm

Table 14. IAlrtTh (B4h) Format

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

IMAX IMIN

IMAX: Maximum current reading. An alert is generated if the current register reading exceeds this value.

IMIN: Maximum current reading. An alert is generated if the current register reading falls below this value.

Serial Number Feature

Each IC provides a unique serial number ID. To read this serial number, clear the AtRateEn and the DPEn

bit in the Config2 register. The 128-bit serial information overwrites the Dynamic Power and AtRate output

registers. To continue Dynamic Power and AtRate operations after reading the serial number, the host should set

Config2.AtRateEn and Config2.DPEn to 1.

Table 15. Serial Number Format

ADDRESS Config2.AtRateEn = 1 || Config2.DPEn = 1 Config2.AtRateEn = 0 && Config2.DPEn = 0

0xD4 MaxPeakPower Serial Number Word0

0xD5 SusPeakPower Serial Number Word1

0xD9 MPPCurrent Serial Number Word2

0xDA SPPCurrent Serial Number Word3

0xDC AtQResidual Serial Number Word4

0xDD AtTTE Serial Number Word5

0xDE AtAvSoc Serial Number Word6

0xDF AtAvCap Serial Number Word7

ModelGauge m5 Memory Space

Registers that relate to functionality of the ModelGauge m5 fuel gauge are located on pages 0h-4h and are

continued on pages Bh and Dh. See the ModelGauge m5 EZ Algorithm section for details of specific register

operation. Register locations marked reserved should not be written to.

Table 16. ModelGauge m5 Register Memory Map

PAGE/

WORD 00h 10h 20h 30h 40h B0h D0h

0h Status FullCapRep TTF Reserved Reserved Status2 RSense /

UserMem3

1h VAlrtTh TTE DevName Reserved Reserved Power ScOcvLim

2h TAlrtTh QRTable00 QRTable10 QRTable20 QRTable30 ID /

UserMem2 VGain

3h SAlrtTh FullSocThr FullCapNom Reserved RGain AvgPower SOCHold

4h AtRate RCell Reserved DieTemp Reserved IAlrtTh MaxPeakPower

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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Figure 4

Table 16. ModelGauge m5 Register Memory Map (continued)

PAGE/

WORD 00h 10h 20h 30h 40h B0h D0h

5h RepCap Reserved Reserved FullCap dQAcc TTFCfg SusPeakPower

6h RepSOC AvgTA Reserved Reserved dPAcc CVMixCap PackResistance

7h Age Cycles AIN Reserved Reserved CVHalfTime SysResistance

8h Temp DesignCap LearnCfg RComp0 Reserved CGTempCo MinSysVoltage

9h VCell AvgVCell FilterCfg TempCo ConvgCfg Curve MPPCurrent

Ah Current MaxMinTemp RelaxCfg VEmpty VFRemCap HibCfg SPPCurrent

Bh AvgCurrent MaxMinVolt MiscCfg Reserved Reserved Config2 ModelCfg

Ch QResidual MaxMinCurr TGain Reserved Reserved VRipple AtQResidual

Dh MixSOC Config TOff FStat QH RippleCfg AtTTE

Eh AvSOC IChgTerm CGain Timer Reserved TimerH AtAvSOC

Fh MixCap AvCap COff ShdnTimer Reserved Reserved AtAvCap

Layout Guidelines

Proper circuit layout as shown in Figure 4 is essential for voltage, temperature, and current measurement accuracy. The

recommended layout guidelines are as follows:

● REG capacitor trace loop area should be minimized. REG should be connected to the GND pin as close as possible

to the IC. This helps filter any noise from the internal regulated supply.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

and Internal Current Sensing

www.maximintegrated.com Maxim Integrated | 29

CREG

PACK -

CBATT

SYSGND

PACK + SYSPWR

MAX17262

NCBATT

SYS

ALRT

SCL

GNDREGSDA

Figure 4. MAX17262 Layout Guide

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

and Internal Current Sensing

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Ordering Information

PART NUMBER TEMP RANGE DESCRIPTION PIN-PACKAGE

MAX17262REWL+ -40°C to +85°C Single-Cell, Internal Sensing 9-WLP

MAX17262REWL+T -40°C to +85°C Single-Cell, Internal Sensing 9-WLP

+Denotes a lead(Pb)-free/RoHS-compliant package.

T = Tape and reel.

MAX17262 5.2μA 1-Cell Fuel Gauge with ModelGauge m5 EZ

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Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

0 7/18 Initial release —

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent

licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max

limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

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