Skyworks Solutions Inc. 的 AAT2785 规格书

2? SKYWORKS 7F w ‘||—-
1
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
General Description
The AAT2785 is a 3-channel 1.8MHz step-down con-
verter for applications where power efficiency and solu-
tion size are critical. The input voltage range is 2.7V to
5.5V and the outputs are adjustable from 0.6V to VIN.
The AAT2785 incorporates a unique low noise architec-
ture which reduces ripple and spectral noise. Channel 3
delivers up to 1.5A output current and channels 1 and 2
deliver up to 600mA each. The AAT2785 uses a high
switching frequency to minimize the size of external com-
ponents. The AAT2785 requires a minimum of external
components to realize a high efficiency triple-output buck
converter minimizing solution cost and PCB footprint.
Each of the 3 regulators has an independent enable pin,
adjustable output voltage and operates with low no load
quiescent current, providing high efficiency over the
entire load range.
The AAT2785 is available in a Pb-free 16 pin TDFN34
package, and is rated over the -40°C to +85°C operating
temperature range.
Features
• VIN Range: 2.7 to 5.5V
• Output Voltage Range: 0.6V to VIN
• Output Current:
Channel 3: 1.5A
Channel 1: 600mA
Channel 2: 600mA
• Low Noise Light Load Mode
• Low Ripple PWM Mode
• Highly Efficient Step-Down Converters
• Low RDS(ON) Integrated Power Switches
• 100% Duty Cycle
• 1.8MHz Switching Frequency
• Internal Soft Start
• Fast 150s Turn-On Time
• Over-Temperature Protection
• Current Limit Protection
• TDFN34-16 Package
• -40°C to 85°C Temperature Range
Applications
• Cellular and Smart Phones
• Digital Cameras
• Handheld Instruments
• Mass Storage Systems
• Microprocessor / DSP Core / IO Power
• PDAs and Handheld Computers
• Portable Media Players
• USB Devices
• Wireless LAN
Typical Application
L3
1.5μH
AAT2785
GND
VP3
EN3
PGND
FB3
LX3
C2
10μF
C5
10μF
C1
10μF
VIN: 2.7V–5.5V
VOUT3: 1.2V, 1.5A
R6
59.0k
R5
59.0k
L2
4.7μH
FB2
LX2
VOUT2: 3.3V, 600mA
R4
29.4k
R3
133k
L1
4.7μH
C3
4.7μF
C4
4.7μF
FB1
LX1
R2
29.4k
R1
133k
VP1_2
EN1
EN2
VOUT1: 3.3V, 600mA
PGND
IN
2
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Pin Descriptions
Pin # Symbol Function
1 PGND2 Power ground return pin 2. Connect to the output and input capacitor return.
2 FB2 Feedback input pin for channel 2. Connect an external resistor divider to this pin to program the
output voltage to the desired value.
3 EN1 Enable pin for channel 1. Active high.
4 EN2 Enable pin for channel 2. Active high.
5 AGND Signal ground.
6 IN Input supply pin for device. Supplies bias for the internal circuitry.
7 EN3 Enable pin for channel 3. Active high.
8 FB3 Feedback input pin for channel 3. Connect an external resistor divider to this pin to program the
output voltage to the desired value.
9 PGND3 Power ground return pin 3. Connect to the output and input capacitor return.
10 LX3 Power switching node for channel 3. Output switching node connects to the output inductor.
11 VP3 Input power supply pin for channel 3. Must be closely decoupled.
12 FB1 Feedback input pin for channel 1. Connect an external resistor divider to this pin to program the
output voltage to the desired value.
13 PGND1 Power ground return pin 1. Connect to the output and input capacitor return.
14 LX1 Power switching node for channel 1 and 2. Output switching node connects to the output inductor.
15 VP1_2 Input power supply pin for channels 1 and 2. Must be closely decoupled.
16 LX2 Power switching node for channel 2. Output switching node connects to the output inductor.
EP EP Exposed pad. Connect to ground directly under the device. Use properly sized vias for thermal cou-
pling to the ground plane. See section on PCB layout guidelines.
Pin Configuration
TDFN34-16
(Top View)
EN1
EN2
AGND
PGND2
FB2
3
IN
EN3
FB3
LX1
PGND1
FB1
LX2
VP1_2
VP3
LX3
PGND3
4
5
1
2
6
7
8
14
13
12
16
15
11
10
9
3
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Absolute Maximum Ratings1
Symbol Description Value Units
VIN, VPInput Voltages to AGND/PGND 6.0 V
VLX LX1, LX2, LX3 to AGND/PGND -0.3 to VIN + 0.3 V
VFB FB1, FB2, FB3 to AGND/PGND -0.3 to VIN + 0.3 V
VEN EN1, EN2, EN3 to AGND/PGND -0.3 to 6.0 V
TJOperating Junction Temperature Range -40 to 150 °C
TLEAD Maximum Soldering Temperature (at leads, 10 sec) 300 °C
Thermal Information
Symbol Description Value Units
PD Maximum Power Dissipation22.0 W
JA Thermal Resistance350 °C/W
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions
specified is not implied. Only one Absolute Maximum Rating should be applied at any one time.
2. Mounted on an FR4 board.
3. Derate 20mW/°C above 25°C ambient temperature.
4
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Electrical Characteristics1
VIN = VP = 3.6V; TA = -40°C to 85°C, unless noted otherwise. Typical values are at TA = 25°C.
Symbol Description Conditions Min Typ Max Units
VIN Input Voltage 2.7 5.5 V
VOUT Output Voltage Tolerance IOUT3 = 0 to 1.5A; IOUT1,2 = 0 to 600mA;
VIN = 2.7 to 5.5V -3.0 3.0 %
VOUT Output Voltage Range 0.6 VIN V
IQ1,2 Quiescent Current Channels 1, 2 Per Channel, No Load 50 100 A
IQ3 Quiescent Current Channel 3 No Load 45 90 A
ISHDN Shutdown Current VEN1 = VEN2 = VEN3 = GND 1.0 A
ILX_LEAK LX Reverse Leakage Current VIN Open, VLX = 5.5V; VEN = 0V 1.0 A
ILX_LEAK LX Leakage Current VIN = 5.5V, VLX = 0 to VIN 1.0 A
IFB Feedback Leakage VFB = 1.0V 0.2 A
ILIM1,2 P-Channel Current Limit 1.8 A
ILIM3 P-Channel Current Limit 3.8 A
RDS(ON)H1,2 High Side Switch On-Resistance 400 m
RDS(ON)L1,2 Low Side Switch On-Resistance 400 m
RDS(ON)H3 High Side Switch On-Resistance 150 m
RDS(ON)L3 Low Side Switch On-Resistance 120 m
VLOADREG Load Regulation ILOAD1,2 = 0 to 600 mA; ILOAD3 = 0 to 1.5A 0.8 %
VLINEREG Line Regulation VIN = 2.7 to 5.5V 0.5 %
FOSC1,2 Oscillator Frequency Channels 1,2 1.8 MHz
FOSC3 Oscillator Frequency Channel 3 1.8 MHz
TSStart-Up Time From Enable to Output Regulation 150 s
TSD Over-Temperature Shutdown Threshold 140 °C
THYS Over-Temperature Shutdown Hysteresis 15 °C
VIL Enable Threshold Low 0.6 V
VIH Enable Threshold High 1.4 V
IEN Enable Input Current VIN = VEN = 5.5V -1.0 1.0 A
1. The AAT2785 is guaranteed to meet performance specifications over the –40°C to +85°C operating temperature range, and is assured by design, characterization and correla-
tion with statistical process controls.
5
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Typical Characteristics
Efficiency vs. Output Current
(Channel 1, 2; VOUT = 3.3V)
Output Current (mA)
Efficiency (%)
15
25
35
45
55
65
75
85
95
105
0.1 1 10 100 1000
VIN = 3.6V
VIN = 4.2V
VIN = 5V
Load Regulation
(Channel 1, 2; VOUT = 3.3V)
Output Current (mA)
Output Error (%)
-5
-4
-3
-2
-1
0
1
2
3
0.1 1 10 100 1000
VIN = 5V
VIN = 4.2V
VIN = 3.6V
Efficiency vs. Output Current
(Channel 3; VOUT = 1.2V)
Output Current (mA)
Efficiency (%)
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100 1000 10000
VIN = 4.2V
VIN = 3.6V
VIN = 2.7V
Load Regulation
(Channel 3; VOUT = 1.2V)
Output Current (mA)
Output Error (%)
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
0.1 1 10 100 1000 10000
VIN = 4.2V
VIN = 3.6V
VIN = 2.7V
Switching Frequency vs. Input Voltage
Input Voltage (V)
Switching Frequency (%)
-10
-8
-6
-4
-2
0
2
4
6
8
10
2.3 2.8 3.3 3.8 4.3 4.8 5.3 5.8
Channel 3
Channel 1, 2
Output Error vs. Temperature
Temperature (°C)
Output Error (%)
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
-40 -15 10 35 60 8
5
Channel 3
Channel 1, 2
6
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Typical Characteristics
Quiescent Current vs. Input Voltage
(Channel 1, 2; VOUT = 3.3V; No Load; Open Loop)
Input Voltage (V)
Supply Current (µA)
0
10
20
30
40
50
60
70
80
90
100
3.2 3.5 3.8 4.1 4.4 4.7 5 5.3 5.6
85°C
25°C
-40°C
Quiescent Current vs. Input Voltage
(Channel 3; VOUT = 1.2V; No Load; Open Loop)
Input Voltage (V)
Supply Current (µA)
0
10
20
30
40
50
60
70
80
90
100
2.6 2.9 3.2 3.5 3.8 4.1 4.4 4.7 5 5.3 5.6
85°C
25°C
-40°C
P-Channel On-Resistance vs. Input Voltage
(Channel 1, 2; VOUT = 3.3V)
Input Voltage (V)
On-Resistance (mΩ
Ω
)
300
400
500
600
700
800
900
1000
3.2 3.6 4 4.4 4.8 5.2 5.6
100°C
85°C
25°C
P-Channel On-Resistance vs. Input Voltage
(Channel 3; VOUT = 1.2V)
Input Voltage (V)
Switch On-Resistance (mΩ
Ω
)
0
50
100
150
200
250
300
2.6 3.1 3.6 4.1 4.6 5.1 5.
6
.
100°C
85°C
25°C
VIH vs. Input Voltage
Input Voltage (V)
VIH (V)
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
2.6 3.1 3.6 4.1 4.6 5.1 5.6
85°C
25°C
-40°C
VIL vs. Input Voltage
Input Voltage (V)
VIL (V)
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
2.6 3.1 3.6 4.1 4.6 5.1 5.6
85°C
25°C
-40°C
7
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Typical Characteristics
Line Regulation
(Channel 1, 2; VOUT = 3.3V)
Input Voltage (V))
Accuracy (%)
-2
-1.5
-1
-0.5
0
0.5
1
3 3.5 4 4.5 5 5.5 6
IOUT = 10mA
IOUT = 150mA
IOUT = 300mA
IOUT = 600mA
Line Regulation
(Channel 3; VOUT = 1.2V)
Input Voltage (V))
Accuracy (%)
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
2.6 3.1 3.6 4.1 4.6 5.1 5.6
IOUT = 10mA
IOUT = 100mA
IOUT = 1000mA
IOUT = 1500mA
Soft Start
(Channel 1, 2; VIN = 5V; VOUT = 3.3V; IOUT = 300mA)
Time (40µs/div)
Enable Voltage (top) (V)
Output Voltage (middle) (V)
Inductor Current
(bottom) (A)
0
1
2
3
4
0
0.5
1
Soft Start
(Channel 3; VIN = 5V; VOUT = 1.2V; IOUT = 1mA)
Time (40µs/div)
Enable Voltage (top) (V)
Output Voltage (middle) (V)
Inductor Current
(bottom) (A)
0
1
2
3
4
0
0.5
1
Soft Start
(Channel 3; VIN = 5V; VOUT = 1.2V; IOUT = 1.5A)
Time (40µs/div)
Enable Voltage (top) (V)
Output Voltage (middle) (V)
Inductor Current
(bottom) (A)
0
1
2
3
4
0
0.5
1
1.5
Output Ripple
(Channel 1, 2; VOUT = 3.3V; VIN = 4.6V; IOUT = 1mA)
Time (400ns/div)
Output Voltage (top) (V)
Inductor Current
(bottom) (A)
-0.01
0
0.01
0
0.1
0.2
8
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Typical Characteristics
Output Ripple
(Channel 1, 2; VOUT = 3.3V; VIN = 4.6V; IOUT = 600mA)
Time (400ns/div)
Output Voltage (top) (V)
Inductor Current
(bottom) (A)
-0.01
0
0.01
0
0.2
0.4
0.6
0.8
Output Ripple
(Channel 3; VOUT = 1.2V; VIN = 4.6V; IOUT = 1.5A)
Time (400ns/div)
Output Voltage (top) (V)
Inductor Current
(bottom) (A)
-0.01
0
0.01
0
0.5
1
1.5
2
Output Ripple
(Channel 1, 2; VOUT = 3.3V; VIN = 3.6V; IOUT = 600mA)
Time (400ns/div)
Output Voltage (top) (V)
Inductor Current
(bottom) (A)
-0.01
0
0.01
0
0.2
0.4
0.6
0.8
Output Ripple
(Channel 3; VOUT = 1.2V; VIN = 3.6V; IOUT = 1.5A)
Time (400ns/div)
Output Voltage (top) (V)
Inductor Current
(bottom) (A)
-0.01
0
0.01
0
0.5
1
1.5
2
Output Ripple
(Channel 1, 2; VOUT = 3.3V; VIN = 5V; IOUT = 600mA)
Time (400ns/div)
Output Voltage (top) (V)
Inductor Current
(bottom) (A)
-0.01
0
0.01
0
0.2
0.4
0.6
0.8
Output Ripple
(Channel 3; VOUT = 1.2V; VIN = 5V; IOUT = 1.5A)
Time (400ns/div)
Output Voltage (top) (V)
Inductor Current
(bottom) (A)
-0.01
0
0.01
0
0.5
1
1.5
2
9
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Typical Characteristics
Output Ripple
(Channel 3; VOUT = 1.2V; VIN = 4.2V; IOUT = 1mA)
Time (100µs/div)
Output Voltage (top) (V)
Inductor Current
(bottom) (A)
-0.02
0
0.02
0.04
0
0.2
0.4
Load Transient
(Channel 1, 2; VIN = 3.6V; IOUT = 100mA to 600mA; VOUT = 3.3V)
Time (200µs/div)
Output Voltage (top) (V)
Output Current (middle) (A)
Inductor Current (bottom) (A)
-0.2
0
0.2
100mA
600mA
100mA
600mA
Load Transient
(Channel 1, 2; VIN = 3.6V; IOUT = 1mA to 600mA; VOUT = 3.3V)
Time (200µs/div)
Output Voltage (top) (V)
Output Current (middle) (A)
Inductor Current (bottom) (A)
-0.2
0
0.2
600mA
600mA
1mA
1mA
Load Transient
(Channel 3; VIN = 5V; IOUT = 0.1A to 1.5A; VOUT = 1.2V)
Time (400µs/div)
Output Voltage (top) (V)
Output Current (middle) (A)
Inductor Current (bottom) (A)
-0.1
0
0.1
100mA
1.5A
1.5A
100mA
Load Transient
(Channel 3; VIN = 5V; IOUT = 0.5A to 1.5A; VOUT = 1.2V)
Time (400µs/div)
Output Voltage (top) (V)
Output Current (middle) (A)
Inductor Current (bottom) (A)
-0.1
0
0.1
500mA
500mA
1.5A
1.5A
Line Transient
(Channel 1, 2; VIN = 4V to 5V; IOUT = 600mA; VOUT = 3.3V)
Time (1ms/div)
Input Voltage (top) (V)
Output Voltage (bottom) (V)
4
5
6
-0.2
-0.1
0
0.1
0.2
10
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Typical Characteristics
Line Transient
(Channel 3; VIN = 3.6V to 4.2V; IOUT = 1.5A; VOUT = 1.2V)
Time (1ms/div)
Input Voltage (top) (V)
Output Voltage (bottom) (V)
3
4
5
6
-0.04
-0.02
0
0.02
0.04
4% CH:
11
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Functional Block Diagram
Logic
Comp.
Error
Amp
Control
Logic
Logic
Error
Amp
Control
Logic
OSCOT
OSC
Comp.
VP3
LX 3
PGND3
VP1_2
LX2
PGND2
LX1
PGND1
FB2
EN2
FB1
EN1
FB3
EN3
Logic
Error
Amp
Control
Logic
Voltage
Ref
Comp.
IN
AGND
Functional Description
The AAT2785 is a high performance power management
IC comprised of 3 buck converters. Each channel has an
independent input voltage and enable pin. Operating at
a switching frequency of 1.8MHz, the converter requires
a minimum of small external components, reducing the
solution cost and PCB footprint.
All converters operate with an input voltage range of
2.7V to 5.5V. The output voltage range is 0.6V to VIN and
is adjustable with an external resistor divider. Channel 3
power devices are sized for 1.5A output current.
Channels 1 and 2 power devices are sized for 600mA
output current while maintaining over 85% efficiency at
full load. Peak efficiency is above 95%. Light load effi-
ciency is maintained at greater than 80% down to 85%
of full load current. All channels have excellent transient
response, load and line regulation. Transient response
time is typically less than 20s.
Soft start limits the current surge seen at the input and
eliminates output voltage overshoot. The enable inputs,
when pulled low, force the respective converter into a
low power non-switching state consuming less than 1A
of current.
For overload conditions, the peak input current is limited.
Also, thermal protection completely disables switching if
internal dissipation becomes excessive, thus protecting
the device from damage. The junction over-temperature
threshold is 140°C with 15°C of hysteresis. Under-voltage
lockout (UVLO) guarantees sufficient VIN bias and proper
operation of all internal circuits prior to activation.
12
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Control Loop
The AAT2785 is a peak current mode step-down con-
verter. The current through the P-channel MOSFET (high
side) is sensed for current loop control, as well as short-
circuit and overload protection. A fixed slope compensa-
tion signal is added to the sensed current to maintain
stability for duty cycles greater than 50%. The peak cur-
rent mode loop appears as a voltage-programmed cur-
rent source in parallel with the output capacitor. The
output of the voltage error amplifier programs the cur-
rent mode loop for the necessary peak switch current to
force a constant output voltage for all load and line con-
ditions. Internal loop compensation terminates the
transconductance voltage error amplifier output. The
reference voltage is internally set to program the con-
verter output voltage greater than or equal to 0.6V.
Soft Start/Enable
Soft start limits the current surge seen at the input and
eliminates output voltage overshoot. When pulled low,
the enable input forces the AAT2785 into a low-power,
non-switching state. The total input current during shut-
down is less than 1A.
Low Dropout Operation
For conditions where the input voltage drops to the out-
put voltage level, the converter duty cycle increases to
100%. As the converter approaches the 100% duty
cycle, the minimum off time initially forces the high side
in time to exceed the 1.8MHz clock cycle and reduce the
effective switching frequency. Once the input drops
below the level where the converter can regulate the
output, the high side P-channel MOSFET is enabled con-
tinuously for 100% duty cycle. At 100% duty cycle the
output voltage tracks the input voltage minus the I*R
drop of the high side P-channel MOSFET.
Current Limit and
Over-Temperature Protection
For overload conditions, the peak input current is limit-
ed. To minimize power dissipation and stresses under
current limit and short-circuit conditions, switching is
terminated after entering current limit for a series of
pulses. Switching is terminated for seven consecutive
clock cycles after a current limit has been sensed for a
series of four consecutive clock cycles. Thermal protec-
tion completely disables switching when internal dissipa-
tion becomes excessive. The junction over-temperature
threshold is 140°C with 15°C of hysteresis. Once an
over-temperature or over-current fault condition is
removed, the output voltage automatically recovers.
Under-Voltage Lockout
Internal bias of all circuits is controlled via the VIN input.
Under-voltage lockout (UVLO) guarantees sufficient VIN
bias and proper operation of all internal circuitry prior to
activation.
Component Selection
Inductor Selection: Channels 1 and 2
The step-down converter uses peak current mode con-
trol with slope compensation to maintain stability for
duty cycles greater than 50%. The output inductor value
must be selected so the inductor current down slope
meets the internal slope compensation requirements.
The internal slope compensation for the adjustable and
low voltage fixed versions of channels 1 and 2 is 0.6A/
s. This equates to a slope compensation that is 75% of
the inductor current down slope for a 1.8V output and
2.2H inductor.
0.75 ⋅ V
O
m = = = 0.6
L
0.75 ⋅ 1.8V
2.2µH
A
µs
0.75 ⋅ V
O
L = = = 4.1µH
m
0.75
⋅
3.3V
0.6
A
µs
In this case a standard 4.7H value is selected. Table 1
displays the suggested inductor values for channels 1
and 2. The 4.7H CDRH2D11 series inductor selected
from Sumida has a 170m DCR and a 0.88A DC current
rating. At full load the inductor DC loss is 15mW which
corresponds to a 1.5% loss in efficiency for a 600mA,
3.3V output.
Inductor Selection: Channel 3
The internal slope compensation for the adjustable and
low voltage fixed versions of channel 3 is 0.75A/s. This
equates to a slope compensation that is 75% of the
inductor current down slope for a 1.8V output and 1.8H
inductor.
0.75 ⋅ V
O
m = = = 0.75
L
0.75 ⋅ 1.8V
1.8µH
A
µs
M—x
13
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
0.75 ⋅ V
O
L = = = 1.2µH
m
0.75
⋅
1.2V
0.75
A
µs
The inductor should be set equal to the output voltage
numeric value in micro henries (H). This guarantees
that there is sufficient internal slope compensation.
Manufacturer’s specifications list both the inductor DC
current rating, which is a thermal limitation, and the
peak current rating, which is determined by the satura-
tion characteristics. The inductor should not show any
appreciable saturation under normal load conditions.
Some inductors may meet the peak and average current
ratings yet result in excessive losses due to a high DCR.
Always consider the losses associated with the DCR and
its effect on the total converter efficiency when selecting
an inductor. For channel 3, the 1.5H LQH32PN1R5NN0L
series Murata inductor has a 68.4m worst case DCR
and a 1.75A DC current rating. At full 1.5A load, the
inductor DC loss is 154mW which gives less than 5% loss
in efficiency for a 1.5A, 1.2V output.
Input Capacitor
Select a 10F to 22F X7R or X5R ceramic capacitor for
the VP1_2 and VP3 inputs. To estimate the required
input capacitor size, determine the acceptable input
ripple level (VPP) and solve for CIN. The calculated value
varies with input voltage and is a maximum when VIN is
double the output voltage.
Confi guration
Output
Voltage Inductor
Slope
Compensation
0.6V adjustable
with external
resistive divider
0.6V-
2.0V 2.2H
0.6A/s
2.5V 3.3H
3.3V 4.7H
Table 1: AAT2785 Inductor Values.
⎛⎞
· 1 -
⎝⎠
VO
VIN
CIN =
VO
VIN
⎛⎞
- ESR · FS
⎝⎠
VPP
IO
⎛⎞
· 1 - = for VIN = 2 · VO
⎝⎠
VO
VIN
VO
VIN
1
4
CIN(MIN) = 1
⎛⎞
- ESR · 4 · FS
⎝⎠
VPP
IO
Always examine the ceramic capacitor DC voltage coef-
ficient characteristics when selecting the proper value.
For example, the capacitance of a 10F, 6.3V, X5R
ceramic capacitor with 5.0V DC applied is actually about
6F. The maximum input capacitor RMS current is:
⎛⎞
IRMS = IO · · 1 -
⎝⎠
VO
VIN
VO
VIN
The input capacitor RMS ripple current varies with the
input and output voltage and will always be less than or
equal to half of the total DC load current.
⎛⎞
· 1 - = D · (1 - D) = 0.52 =
⎝⎠
VO
VIN
VO
VIN
1
2
for VIN = 2 · VO
IO
RMS(MAX)
I2
=
The term
⎛⎞
· 1 -
⎝⎠
VO
VIN
VO
VIN
appears in both the input voltage
ripple and input capacitor RMS current equations and is
at a maximum when VO is twice VIN. This is why the input
voltage ripple and the input capacitor RMS current ripple
are a maximum at 50% duty cycle. The input capacitor
provides a low impedance loop for the edges of pulsed
current drawn by the AAT2785. Low ESR/ESL X7R and
X5R ceramic capacitors are ideal for this function. To
minimize stray inductance, the capacitor should be placed
as closely as possible to the IC. This keeps the high fre-
quency content of the input current localized, minimizing
EMI and input voltage ripple. The proper placement of
the input capacitor (C1) can be seen in the evaluation
board layout in the Layout section of this datasheet (see
Figure 2). A laboratory test set-up typically consists of
two long wires running from the bench power supply to
the evaluation board input voltage pins. The inductance
of these wires, along with the low-ESR ceramic input
capacitor, can create a high Q network that may affect
converter performance. This problem often becomes
apparent in the form of excessive ringing in the output
voltage during load transients. Errors in the loop phase
and gain measurements can also result. Since the induc-
tance of a short PCB trace feeding the input voltage is
significantly lower than the power leads from the bench
power supply, most applications do not exhibit this prob-
lem. In applications where the input power source lead
inductance cannot be reduced to a level that does not
affect the converter performance, a high ESR tantalum or
14
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
aluminum electrolytic should be placed in parallel with
the low ESR/ESL bypass ceramic capacitor. This dampens
the high Q network and stabilizes the system.
Output Capacitor: Channels 1 and 2
The output capacitor limits the output ripple and pro-
vides holdup during large load transitions. A 4.7F to
10F X5R or X7R ceramic capacitor typically provides
sufficient bulk capacitance to stabilize the output during
large load transitions and has the ESR and ESL charac-
teristics necessary for low output ripple. The output volt-
age droop due to a load transient is dominated by the
capacitance of the ceramic output capacitor. During a
step increase in load current, the ceramic output capac-
itor alone supplies the load current until the loop
responds. Within two or three switching cycles, the loop
responds and the inductor current increases to match
the load current demand. The relationship of the output
voltage droop during the three switching cycles to the
output capacitance can be estimated by:
COUT =
3 · ΔILOAD
VDROOP · FS
Once the average inductor current increases to the DC
load level, the output voltage recovers. The above equa-
tion establishes a limit on the minimum value for the
output capacitor with respect to load transients. The
internal voltage loop compensation also limits the mini-
mum output capacitor value to 4.7F. This is due to its
effect on the loop crossover frequency (bandwidth),
phase margin, and gain margin. Increased output capac-
itance will reduce the crossover frequency with greater
phase margin.
Output Capacitor: Channel 3
The output capacitor limits the output ripple and pro-
vides holdup during large load transitions. A 10F to
22F X5R or X7R ceramic capacitor typically provides
sufficient bulk capacitance to stabilize the output during
large load transitions and has the ESR and ESL charac-
teristics necessary for low output ripple.
Adjustable Output Resistor Selection
The output voltage for each channel of the AAT2785 is
programmed with external resistors R1, R2, R3, R4, R5,
and R6. To limit the bias current required for the exter-
nal feedback resistor string while maintaining good noise
immunity, the minimum suggested value for R2 and R4
are 29.4 k, and R6 is 59k. Although a larger value will
further reduce quiescent current, it will also increase the
impedance of the feedback node, making it more sensi-
tive to external noise and interference. Table 2 and Table
3 summarize the resistor values for various output volt-
ages of channel 1, channel 2, and channel 3.
VOUT (V)
R2 = R4 = 29.4kΩ
R1 = R3 (kΩ)
0.8 10
0.9 15
1.0 20
1.1 25
1.2 29
1.3 34
1.4 39
1.5 44
1.8 59
1.9 61
2.0 69
2.5 93
3.0 118
3.3 132
Table 2: AAT2785 Resistor Values for Various
Output Voltages of Channel 1 and Channel 2.
VOUT (V)
R6 = 59k
R5 (k)
R6 = 221k
R5 (k)
0.8 19.6 75
0.9 29.4 113
1.0 39.2 150
1.1 49.9 187
1.2 59.0 221
1.3 68.1 261
1.4 78.7 301
1.5 88.7 332
1.8 118 442
1.85 124 464
2.0 137 523
2.5 187 715
3.0 237 887
3.3 267 1000
Table 3: AAT2785 Resistor Values for Various
Output Voltages of Channel 3.
15
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Thermal Calculations
There are three types of losses associated with the
AAT2785 step-down converter: switching losses, con-
duction losses, and quiescent current losses. Conduction
losses are associated with the RDS(ON) characteristics of
the power output switching devices. Switching losses are
dominated by the gate charge of the power output
switching devices. At full load, assuming continuous con-
duction mode (CCM), a simplified form of the losses is
given by:
PTOTAL
IO
2 · (RDS(ON)H · VO + RDS(ON)L · [VIN - VO])
VIN
=
+ (tsw · FS · IO + IQ) · VIN
IQ is the step-down converter quiescent current. The
term tSW is used to estimate the full load step-down con-
verter switching losses. For the condition where the
step-down converter is in dropout at 100% duty cycle,
the total device dissipation reduces to:
PTOTAL = IO
2 · RDSON(H) + IQ · VIN
Since RDS(ON), quiescent current, and switching losses all
vary with input voltage, the total losses should be inves-
tigated over the complete input voltage range. Given the
total losses, the maximum junction temperature can be
derived from the JA for the TDFN34-16 package, which
is 50°C/W.
TJ(MAX) = PTOTAL · ΘJA + TAMB
Layout
The suggested PCB layout for the AAT2785 is shown in
Figures 2 and 3. The following guidelines should be used
to help ensure a proper layout.
1. The power input capacitors (C5 and C8) should be
connected as closely as possible to VP1_2, VP3 and
PGND1,2,3 as shown in Figure 2. Due to the pin
placement of VP1_2 and VP3 for all converters,
proper decoupling is not possible with just one input
capacitor.
2. C1 and R7 are optional low pass filter components
for the IN supply pin for the device if additional noise
decupling is required in a noisy system
3.
C2 and L1, C6 and L2, C10 and L3 should be con-
nected as closely as possible. The connection of L1, 2,
3 to the LX1, 2, 3 pin should be as short as possible.
4. The feedback trace or FB pin should be separate
from any power trace and connect as closely as pos-
sible to the load point. Sensing along a high-current
load trace will degrade DC load regulation.
5. The resistance of the trace from the load returns to
PGND1, 2 and 3 should be kept to a minimum. This
will help to minimize any error in DC regulation due
to differences in the potential of the internal signal
ground and the power ground.
6. Connect unused signal pins to ground to avoid
unwanted noise coupling.
7. For good thermal coupling, PCB vias are required
from the pad for the TDFN paddle to the bottom
ground plane. The via diameter should be 0.3mm to
0.33mm and positioned on a 1.2mm grid.
16
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Evaluation Board Schematic
1
1
VOUT3
VOUT2
VOUT1
1
1
3
2
EN1
1
3
2
EN2
1
3
2
EN3
C1
10μF
C4
10μF
C5
10μF
C8
10μF
4.7μH
L1
4.7μH
L2
1.5uH
L3
R5
59K
R6
59K
R3
133k
R4
29.4k
R1
133K
R2
29.4K
C10
10μF
C6
4.7μF
C2
4.7μF
1
LX2
1
LX3
1
LX1
C9
opt
R7
0
1PGND
1
PGND
1
Vi n
PGND2
1
FB2
2
EN1
3
EN2
4
GND
5
VIN
6
EN3
7
FB3
8PGND3 9
LX3 10
VP3 11
FB1 12
PGND1 13
LX1 14
VP1_2 15
LX2 16
AAT2785
U1
C7
opt
C3
opt
Figure 1: AAT2785 Evaluation Board Schematic.
Evaluation Board Layout
Figure 2: AAT2785 Evaluation Board Figure 3: AAT2785 Evaluation Board
Component Side Layout. Solder Side Layout.
17
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Component Part Number Manufacturer Description
U1 AAT2785 AATI 3-Channel Step-Down DC/DC Converter
L1, L2 CDRX2D11 Sumida 4.7H 0.88A 170m (3.2x3.2x1.2)mm Shielded
L3 LQH32PN1R5NN0L Murata 1.5H series Murata inductor has a 68.4m worst case DCR and a
1.75A DC
C1 Generic Optional
C2, C6 GMR219R61A475KE19 Murata 4.7F 10V 0805
C5, C8, C10 GMR21BR60J106KE19 Murata 10F 6.3V 0805
C9 Generic 56pF 6.3V 0402
R1, R3 Generic 133K 0402
R2, R4 Generic 29.4K 0402
R5, R6 Generic 59K 0402
R7 Generic Optional
Table 4: AAT2785 Evaluation Board Bill of Materials.
18
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Design Example
Specifications
VO3 1.2V @ 1.5A (adjustable using 0.6V version), pulsed load ILOAD = 1.5A
VO1 3.3V @ 600mA (adjustable using 0.6V version), pulsed load ILOAD = 600mA
VO2 3.3V @ 600mA (adjustable using 0.6V version), pulsed load ILOAD = 600mA
VIN 2.7V to 4.2V (3.6V nominal)
FS 1.8MHz
TAMB 85°C
Channel 3 Output Inductor
0.75 ⋅ V
O
L = = = 1.2µH
m
0.75
⋅
1.2V
0.75
A
µs
; use 1.5H. (see Table 4).
Select Murata LQH32PN1R5NN0L 1.5H 1.75A DC current rating DCR = 68m.
V
O3
V
O3
1.5
V
1.5V
ΔI
3
= 1 - = ⋅ 1 - = 357m
A
L ⋅ F
V
IN
1.5µH ⋅ 1.8MHz
4.2V
I
PK3
= 1.5A + 0.357A = 1.9A
P
L3
= I
O3
2
⋅ DCR = 1.5A
2
⋅ 68mΩ = 153mW
⎛
⎝⎞
⎠
⎛
⎝⎞
⎠
Channels 1 and 2 Output Inductors
0.75 ⋅ V
O
L1 = L2 = = = 4.1µH
m
0.75
⋅
3.3V
0.6
A
µs
; use 4.7H. (see Table 4)
Select Sumida CDRH2D11 4.7H 0.88A DC current rating DCR = 170m.
V
O1
V
O1
3.3
V
3.3V
ΔI
1
= ΔI
2
= 1 - = ⋅ 1 - = 84m
A
L ⋅ F
V
IN
4.7µH ⋅ 1.8MHz
4.2V
I
PK1
= I
PK2
= 0.6A + 0.084A = 0.7A
P
L1
= P
L2
= I
O1
2
⋅ DCR = 0.6
2
⋅ 170mΩ = 61.2mW
⎛
⎝⎞
⎠
⎛
⎝⎞
⎠
1.2V‘ (4.2V - 1.2V) f f' 1.5uH-1.8MHz-4.2V . 3.3V‘(4.2V-3.3V) f [ 4.7uH-1.8MHz-4.2V 1 1 h 30mV | 1.5A 1 vi 15mV 0.6A = 92mA = 24m A
19
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Channel 3 Output Capacitor
1
23
1 1.2V · (4.2V - 1.2V)
1.5µH · 1.8MHz · 4.2V
23
RMS(MAX)
IL · FS · VIN(MAX)
= ·
·
3 · ΔILOAD1
VDROOP · FS
3 · 1.5A
0.2V · 1.8MHz
COUT3 = = = 12.5µF; use 10 to 22µF
· = 92m
A
·
VOUT · (VIN(MAX) - VOUT)=
PESR = ESR · IRMS2 = 5mΩ · 92mA2 = 0.04mW
Channels 1 and 2 Output Capacitors
1
23
1 3.3V · (4.2V - 3.3V)
4.7µH · 1.8MHz · 4.2V
23
RMS(MAX)
IL · FS · VIN(MAX)
= ·
·
3 · ΔILOAD1
VDROOP · FS
3 · 0.6A
0.2V · 1.8MHz
COUT1 = COUT2 = = = 5µF; use 5.6µF
· = 24m
·
VOUT1 · (VIN(MAX) - VOUT1)=
PESR = ESR · IRMS2 = 5mΩ · 28.9mA2 = 2.9µW
Channel 3 Input Capacitor
Input Ripple VPP = 30mV
CIN3 = = = 9.3µF; use 10µF
1
⎛⎞
- ESR · 4 · FS
⎝⎠
VPP
IO3
1
⎛⎞
- 5mΩ · 4 · 1.8MHz
⎝⎠
30mV
1.5A
IO
RMS(MAX)
I
PESR = ESR · IRMS
2 = 5mΩ · (0.75A)2 = 3mW
2
= = 0.75A
Channels 1 and 2 Input Capacitors
Input Ripple VPP = 15mV
CIN1 = CIN2 = = = 7µF; use 10µF
1
⎛⎞
- ESR · 4 · FS
⎝⎠
VPP
IO1
1
⎛⎞
- 5mΩ · 4 · 1.8MHz
⎝⎠
15mV
0.6A
IO
RMS(MAX)
I
PESR = ESR · IRMS
2 = 5mΩ · (0.3A)2 = 0.45mW
2
= = 0.3A
20
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
AAT2785 Losses
Total loss can be estimated by calculating the dropout (VIN = VO) losses where the power MOSFETs' RDS(ON) will be at the
maximum value. All values assume an 85°C ambient temperature and a 120°C junction temperature with the TDFN
50°C/W package.
PLOSS = IO32 · RDS(ON)H3 +2 · (IO12 · RDS(ON)H1,2) = 1.5A2 · 120m +2 · (0.6A2 · 400m) = 0.558W
TJ(MAX) = TAMB + JA · PLOSS = 85°C + 50°C · 0.558W = 113°C.
Manufacturer Part Number
Inductance
(μH)
Max DC
Current (A)
DCR
()
Size (mm)
LxWxH Type
Sumida CDRH2D11 1.5 1.48 0.068 3.2x3.2x1.2 Shielded
Sumida CDRH2D11 2.2 1.27 0.098 3.2x3.2x1.2 Shielded
Sumida CDRH2D11 3.3 1.02 0.123 3.2x3.2x1.2 Shielded
Sumida CDRH2D11 4.7 0.88 0.170 3.2x3.2x1.2 Shielded
Taiyo Yuden CBC2518T 1.0 1.2 0.08 2.5x1.8x1.8 Wire Wound Chip
Taiyo Yuden CBC2518T 2.2 1.1 0.13 2.5x1.8x1.8 Wire Wound Chip
Taiyo Yuden CBC2518T 4.7 0.92 0.2 2.5x1.8x1.8 Wire Wound Chip
Taiyo Yuden CBC2016T 2.2 0.83 0.2 2.0x1.6x1.6 Wire Wound Chip
Table 5: Typical Surface Mount Inductors.
21
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Ordering Information
Package
Voltage
Marking1Part Number (Tape and Reel)2
Channel 1 Channel 2 Channel 3
TDFN34-16 0.6 0.6 0.6 2NXYY AAT2785IRN-AAA-T1
Skyworks Green™ products are compliant with
all applicable legislation and are halogen-free.
For additional information, refer to Skyworks
Definition of Green™, document number
SQ04-0074.
Legend
Voltage Code
Adjustable
(0.6V) A
1. XYY = assembly and date code.
2. Sample stock is generally held on all part numbers listed in BOLD.
ccpccccc #33333: .
22
AAT2785
Three-Channel Step-Down DC/DC Converter
DATA SHEET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202045A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 11, 2012
Copyright © 2012 Skyworks Solutions, Inc. All Rights Reserved.
Information in this document is provided in connection with Skyworks Solutions, Inc. (“Skyworks”) products or services. These materials, including the information contained herein, are provided by Skyworks as a
service to its customers and may be used for informational purposes only by the customer. Skyworks assumes no responsibility for errors or omissions in these materials or the information contained herein. Sky-
works may change its documentation, products, services, specifi cations or product descriptions at any time, without notice. Skyworks makes no commitment to update the materials or information and shall have no
responsibility whatsoever for confl icts, incompatibilities, or other diffi culties arising from any future changes.
No license, whether express, implied, by estoppel or otherwise, is granted to any intellectual property rights by this document. Skyworks assumes no liability for any materials, products or information provided here-
under, including the sale, distribution, reproduction or use of Skyworks products, information or materials, except as may be provided in Skyworks Terms and Conditions of Sale.
THE MATERIALS, PRODUCTS AND INFORMATION ARE PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE, INCLUDING FITNESS FOR A PARTICULAR
PURPOSE OR USE, MERCHANTABILITY, PERFORMANCE, QUALITY OR NON-INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHT; ALL SUCH WARRANTIES ARE HEREBY EXPRESSLY DISCLAIMED. SKYWORKS DOES
NOT WARRANT THE ACCURACY OR COMPLETENESS OF THE INFORMATION, TEXT, GRAPHICS OR OTHER ITEMS CONTAINED WITHIN THESE MATERIALS. SKYWORKS SHALL NOT BE LIABLE FOR ANY DAMAGES, IN-
CLUDING BUT NOT LIMITED TO ANY SPECIAL, INDIRECT, INCIDENTAL, STATUTORY, OR CONSEQUENTIAL DAMAGES, INCLUDING WITHOUT LIMITATION, LOST REVENUES OR LOST PROFITS THAT MAY RESULT FROM
THE USE OF THE MATERIALS OR INFORMATION, WHETHER OR NOT THE RECIPIENT OF MATERIALS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Skyworks products are not intended for use in medical, lifesaving or life-sustaining applications, or other equipment in which the failure of the Skyworks products could lead to personal injury, death, physical or en-
vironmental damage. Skyworks customers using or selling Skyworks products for use in such applications do so at their own risk and agree to fully indemnify Skyworks for any damages resulting from such improper
use or sale.
Customers are responsible for their products and applications using Skyworks products, which may deviate from published specifi cations as a result of design defects, errors, or operation of products outside of pub-
lished parameters or design specifi cations. Customers should include design and operating safeguards to minimize these and other risks. Skyworks assumes no liability for applications assistance, customer product
design, or damage to any equipment resulting from the use of Skyworks products outside of stated published specifi cations or parameters.
Skyworks, the Skyworks symbol, and “Breakthrough Simplicity” are trademarks or registered trademarks of Skyworks Solutions, Inc., in the United States and other countries. Third-party brands and names are for
identifi cation purposes only, and are the property of their respective owners. Additional information, including relevant terms and conditions, posted at www.skyworksinc.com, are incorporated by reference.
Package Information
TDFN34-16
3.000
±
0.050 1.600
±
0.050
0.050
±
0.050 0.229
±
0.051
(4x)
0.850 MAX
4.000
±
0.050
3.300
±
0.050
Index Area
Detail "A"
Top View Bottom View
Side View
0.350
±
0.100
0.230
±
0.0500.450
±
0.050
Detail "A"
Pin 1 Indicator
(optional)
C0.3
All dimensions in millimeters.
1. The leadless package family, which includes QFN, TQFN, DFN, TDFN and STDFN, has exposed copper (unplated) at the end of the lead terminals due to the manufacturing
process. A solder fillet at the exposed copper edge cannot be guaranteed and is not required to ensure a proper bottom solder connection.