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TECHNOLOGY
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LT3014
1
3014fd
TYPICAL APPLICATION
FEATURES
APPLICATIONS
DESCRIPTION
20mA, 3V to 80V
Low Dropout Micropower
Linear Regulator
The LT
®
3014 is a high voltage, micropower low dropout
linear regulator. The device is capable of supplying 20mA of
output current with a dropout voltage of 350mV. Designed
for use in battery-powered or high voltage systems, the low
quiescent current (7μA operating and 1μA in shutdown)
makes the LT3014 an ideal choice. Quiescent current is
also well controlled in dropout.
Other features of the LT3014 include the ability to operate
with very small output capacitors. The regulators are stable
with only 0.47μF on the output while most older devices
require between 10μF and 100μF for stability. Small ceramic
capacitors can be used without the necessary addition of
ESR as is common with other regulators. Internal protec-
tion circuitry includes reverse-battery protection, current
limiting, thermal limiting and reverse current protection.
The device is available as an adjustable device with a 1.22V
reference voltage. The LT3014 regulator is available in the
5-lead ThinSOT and 8-lead DFN packages.
Dropout Voltage
n Wide Input Voltage Range: 3V to 80V
n Low Quiescent Current: 7µA
n Low Dropout Voltage: 350mV
n Output Current: 20mA
n LT3014HV Survives 100V Transients (2ms)
n No Protection Diodes Needed
n Adjustable Output from 1.22V to 60V
n 1µA Quiescent Current in Shutdown
n Stable with 0.47µF Output Capacitor
n Stable with Aluminum, Tantalum or Ceramic
Capacitors
n Reverse-Battery Protection
n No Reverse Current Flow from Output
n Thermal Limiting
■ Available in 5-Lead ThinSOT
TM
and
8-Lead DFN Packages
n
Low Current High Voltage Regulators
n
Regulator for Battery-Powered Systems
n Telecom Applications
n Automotive Applications
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 6118263, 6144250.
5V Supply with Shutdown
IN
LT3014
SHDN
1μF
VIN
5.4V TO
80V
OUT
ADJ
GND
3014 TA01
VOUT
5V
20mA
0.47μF
3.92M
1.27M
VSHDN
<0.3V
>2.0V
OUTPUT
OFF
ON
400
350
300
250
200
150
100
50
0
3014 TA02
OUTPUT CURRENT (mA)
DROPOUT VOLTAGE (mV)
0 4 10 12268 14161820
LT3014
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L7HCUEM
LT3014
2
3014fd
ABSOLUTE MAXIMUM RATINGS
IN Pin Voltage, Operating ................................... ±80V
Transient (2ms Survival, LT3014HV) ................ +100V
OUT Pin Voltage ................................................. ±60V
IN to OUT Differential Voltage ............................ ±80V
ADJ Pin Voltage ................................................... ±7V
SHDN Pin Input Voltage ..................................... ±80V
Output Short-Circuit Duration ......................Indefi nite
(Note 1)
5 OUT
4 ADJ
IN 1
TOP VIEW
S5 PACKAGE
5-LEAD PLASTIC SOT-23
GND 2
SHDN 3
TJMAX = 125°C, θJA = 150°C/ W
θJC = 25°C/W MEASURED AT PIN 2
SEE APPLICATIONS INFORMATION SECTION
TOP VIEW
DD PACKAGE
8-LEAD (3mm s 3mm) PLASTIC DFN
EXPOSED PAD IS GND (PIN 9) MUST BE SOLDERED TO PCB
5
6
7
8
4
3
2
1OUT
ADJ
NC
GND
IN
NC
NC
SHDN
9
TJMAX = 125°C, θJA = 40°C/ W
θJC = 10°C/W MEASURED AT PIN 9
PIN CONFIGURATION
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3014ES5#PBF LT3014ES5#TRPBF LTBMF 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014IS5#PBF LT3014IS5#TRPBF LTBMF 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014HVES5#PBF LT3014HVES5#TRPBF LTBRS 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014HVIS5#PBF LT3014HVIS5#TRPBF LTBRS 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014EDD#PBF LT3014EDD#TRPBF LBMG 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LT3014IDD#PBF LT3014IDD#TRPBF LBMG 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LT3014HVEDD#PBF LT3014HVEDD#TRPBF LBRT 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LT3014HVIDD#PBF LT3014HVIDD#TRPBF LBRT 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3014ES5 LT3014ES5#TR LTBMF 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014IS5 LT3014IS5#TR LTBMF 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014HVES5 LT3014HVES5#TR LTBRS 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014HVIS5 LT3014HVIS5#TR LTBRS 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014EDD LT3014EDD#TR LBMG 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LT3014IDD LT3014IDD#TR LBMG 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LT3014HVEDD LT3014HVEDD#TR LBRT 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LT3014HVIDD LT3014HVIDD#TR LBRT 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifi cations, go to: http://www.linear.com/tapeandreel/
Storage Temperature Range
ThinSOT Package .......................... –65°C to 150°C
DFN Package ..................................–65°C to 125°C
Operating Junction Temperature Range
(Notes 3, 10, 11) ............................–40°C to 125°C
Lead Temperature
(Soldering, 10 sec, SOT-23 Package) ............300°C
LT3014
L7 LJUW
LT3014
3
3014fd
ELECTRICAL CHARACTERISTICS
SYMBOL CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage ILOAD = 20mA l3 3.3 V
ADJ Pin Voltage
(Notes 2, 3)
VIN = 3.3V, ILOAD = 100μA
3.3V < VIN < 80V, 100μA < ILOAD < 20mA l
1.200
1.180
1.220
1.220
1.240
1.260
V
V
Line Regulation ΔVIN = 3.3V to 80V, ILOAD = 100μA (Note 2) l110 mV
Load Regulation (Note 2) VIN = 3.3V, ΔILOAD = 100μA to 20mA
VIN = 3.3V, ΔILOAD = 100μA to 20mA l
13 25
40
mV
mV
Dropout Voltage
VIN = VOUT(NOMINAL) (Notes 4, 5)
ILOAD = 100μA
ILOAD = 100μA l
120 180
250
mV
mV
ILOAD = 1mA
ILOAD = 1mA l
200 270
360
mV
mV
ILOAD = 10mA
ILOAD = 10mA l
300 350
450
mV
mV
ILOAD = 20mA
ILOAD = 20mA l
350 410
570
mV
mV
GND Pin Current
VIN = VOUT(NOMINAL) (Notes 4, 6)
ILOAD = 0mA
ILOAD = 100μA
ILOAD = 1mA
ILOAD = 10mA
ILOAD = 20mA
l
l
l
l
l
7
12
40
250
650
20
30
100
450
1000
μA
μA
μA
μA
μA
Output Voltage Noise COUT = 0.47μF, ILOAD = 20mA, BW = 10Hz to 100kHz 115 μVRMS
ADJ Pin Bias Current (Note 7) 4 10 nA
Shutdown Threshold VOUT = Off to On
VOUT = On to Off
l
l0.25
1.3
1.3
2V
V
SHDN Pin Current (Note 8) VSHDN = 0V
VSHDN = 6V
l
l
1
0
4
1
μA
μA
Quiescent Current in Shutdown VIN = 6V, VSHDN = 0V l14 μA
Ripple Rejection VIN = 7V (Avg), VRIPPLE = 0.5VP-P , fRIPPLE = 120Hz,
ILOAD = 20mA
60 70 dB
Current Limit VIN = 7V, VOUT = 0V
VIN = 3.3V, ΔVOUT = –0.1V (Note 2) l25
70 mA
mA
Input Reverse Leakage Current VIN = –80V, VOUT = 0V l6mA
Reverse Output Current (Note 9) VOUT = 1.22V, VIN < 1.22V (Note 2) 2 4 μA
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at TJ = 25°C.
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LT3014 is tested and specifi ed for these conditions with the
ADJ pin connected to the OUT pin.
Note 3: Operating conditions are limited by maximum junction
temperature. The regulated output voltage specifi cation will not apply
for all possible combinations of input voltage and output current. When
operating at maximum input voltage, the output current range must be
limited. When operating at maximum output current, the input voltage
range must be limited.
Note 4: To satisfy requirements for minimum input voltage, the LT3014 is
tested and specifi ed for these conditions with an external resistor divider
(249k bottom, 392k top) for an output voltage of 3.3V. The external
resistor divider adds a 5µA DC load on the output.
Note 5: Dropout voltage is the minimum input to output voltage differential
needed to maintain regulation at a specifi ed output current. In dropout, the
output voltage is equal to (VIN – VDROPOUT).
Note 6: GND pin current is tested with VIN = VOUT (nominal) and a current
source load. This means the device is tested while operating in its dropout
region. This is the worst-case GND pin current. The GND pin current
decreases slightly at higher input voltages.
Note 7: ADJ pin bias current fl ows into the ADJ pin.
Note 8: SHDN pin current fl ows out of the SHDN pin.
Note 9: Reverse output current is tested with the IN pin grounded and the
OUT pin forced to the rated output voltage. This current fl ows into the OUT
pin and out of the GND pin.
Note 10: The LT3014 is tested and specifi ed under pulse load conditions
such that TJ ≅ TA. The LT3014E is 100% tested at TA = 25°C. Performance
at –40°C to 125°C is assured by design, characterization, and statistical
LT3014
VSHDN = Vw
o = TEST POWTS
\
LT3014
4
3014fd
TYPICAL PERFORMANCE CHARACTERISTICS
OUTPUT CURRENT (mA)
DROPOUT VOLTAGE (mV)
3014 G01
01642 6 10 14 18812 20
500
450
400
300
350
250
200
150
100
50
0
TJ = 125oC
TJ = 25oC
OUTPUT CURRENT (mA)
0
DROPOUT VOLTAGE (mV)
200
400
600
100
300
500
4 8 12 16
3014 G02
2020 6 10 14 18
= TEST POINTS
TJb 125oC
TJb 25oC
TEMPERATURE (oC)
–50
0
DROPOUT VOLTAGE (mV)
50
150
200
250
500
350
050 75
3014 G03
100
400
450
300
–25 25 100 125
IL = 20mA
IL = 10mA
IL = 1mA
IL = 100MA
TEMPERATURE (oC)
–50
QUIESCENT CURRENT (μA)
14
25
3014 G04
8
4
–25 0 50
2
0
16
12
10
6
75 100 125
VSHDN = 0V
VIN = 6V
RL = d
IL = 0
VSHDN = VIN
TEMPERATURE (oC)
–50
ADJ PIN VOLTAGE (V)
1.235
25
3014 G05
1.220
1.210
–25 0 50
1.205
1.200
1.240
1.230
1.225
1.215
75 100 125
IL = 100μA
08
213579
4610
16
14
12
10
8
6
4
2
0
INPUT VOLTAGE (V)
QUIESCENT CURRENT (μA)
3014 G06
VSHDN = VIN
VSHDN = 0V
TJ = 25oC
RL = d
VOUT = 1.22V
Typical Dropout Voltage Guaranteed Dropout Voltage Dropout Voltage
Quiescent Current ADJ Pin Voltage Quiescent Current
process controls. The LT3014I is guaranteed over the full –40°C to 125°C
operating junction temperature.
Note 11: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specifi ed maximum operating junction
temperature may impair device reliability.
ELECTRICAL CHARACTERISTICS
LT3014
NT FLO
URRENT FLOWS a
MD OUTPUT Pm
L7 LJUW
LT3014
5
3014fd
INPUT VOLTAGE (V)
0
GND PIN CURRENT (μA)
600
800
1000
8
3014 G07
400
200
500
700
900
300
100
02143679510
TJ = 25oC
*FOR VOUT = 1.22V
RL = 617
IL = 20mA*
RL = 1227
IL = 10mA*
RL = 1.22k
IL = 1mA*
OUTPUT CURRENT (mA)
0
GND PIN CURRENT (μA)
600
800
1000
16
3014 G08
400
200
500
700
900
300
100
042 86 12 14 18
10 20
VIN = 3.3V
TJ = 25oC
VOUT = 1.22V
TEMPERATURE (oC)
–50
2.0
1.8
1.6
1.2
1.4
1.0
0.8
0.6
0.4
0.2
0
3014 G09
250–25 50 75 125100
SHDN PIN THRESHOLD (V)
TYPICAL PERFORMANCE CHARACTERISTICS
GND Pin Current GND Pin Current vs ILOAD SHDN Pin Threshold
SHDN PIN VOLTAGE (V)
0
SHDN PIN CURRENT (μA)
0.4
0.8
1.2
0.2
0.6
1.0
3014 G10
012340.5 1.5 2.5 3.5
TJ = 25oC
CURRENT FLOWS
OUT OF SHDN PIN
TEMPERATURE (oC)
–50
SHDN PIN CURRENT (μA)
1.4
25
3014 G11
0.8
0.4
–25 0 50
0.2
0
1.6
1.2
1.0
0.6
75 100 125
VSHDN = 0V
CURRENT FLOWS
OUT OF SHDN PIN
TEMPERATURE (oC)
ADJ PIN BIAS CURRENT (nA)
25
3014 G12
–25 0 50
–50 75 100 125
14
12
10
8
6
4
2
0
INPUT VOLTAGE (V)
0
CURRENT LIMIT (mA)
16
3014 G13
428612141810 20
70
40
20
10
0
80
60
50
30
VOUT = 0V
TJ = 25oC
TEMPERATURE (oC)
–50
0
CURRENT LIMIT (mA)
10
30
40
50
100
70
050 75
3014 G14
20
80
90
60
–25 25 100 125
VIN = 7V
VOUT = 0V
OUTPUT VOLTAGE (V)
0
REVERSE OUTPUT CURRENT (μA)
30
40
50
8
3014 G15
20
10
25
35
45
15
5
021 43 67 9
510
TJ = 25oC
VIN = 0V
VOUT = VADJ
CURRENT FLOWS
INTO OUTPUT PIN
ADJ PIN
ESD CLAMP
SHDN Pin Current SHDN Pin Current ADJ Pin Bias Current
Current Limit Current Limit Reverse Output Current
LT3014
L7HCU§QB
LT3014
6
3014fd
TEMPERATURE (oC)
–50
REVERSE OUTPUT CURRENT (μA)
7
25
3014 G16
4
2
–25 0 50
1
0
8
6
5
3
75 100 125
VIN = 0V
VOUT = VADJ = 1.22V
TEMPERATURE (oC)
–50
RIPPLE REJECTION (dB)
70
25
3014 G17
64
60
–25 0 50
58
56
72
68
66
62
75 100 125
VIN = 7V + 0.5VP-P
RIPPLE AT f = 120Hz
IL = 20mA
FREQUENCY (Hz)
10
RIPPLE REJECTION (dB)
100 1k 10k 100k 1M
3014 G18
70
40
20
10
0
80
60
50
30
VIN = 7V + 50mVRMS RIPPLE
IL = 20mA
COUT = 4.7μF
COUT = 0.47μF
TYPICAL PERFORMANCE CHARACTERISTICS
Reverse Output Current Input Ripple Rejection Input Ripple Rejection
TEMPERATURE (oC)
–50
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
25 75
3014 G19
–25 0 50 100 125
MINIMUM INPUT VOLTAGE (V)
ILOAD = 20mA
TEMPERATURE (oC)
–50
LOAD REGULATION (mV)
–5
25
3014 G20
–20
–30
–25 0 50
–35
–40
0
–10
–15
–25
75 100 125
$IL = 100μA TO 20mA
VOUT = 1.22V
FREQUENCY (Hz)
0.1
OUTPUT NOISE SPECTRAL DENSITY (MV/Hz)
1
10 1k 10k 100k
3014 G21
0.01
100
10 COUT = 0.47μF
IL = 20mA
VOUT = 1.22V
1ms/DIV
VOUT
200μV/DIV
3014 G22
COUT = 0.47μF
IL = 200mA
VOUT = 1.22V
TIME (μs)
0
OUTPUT VOLTAGE
DEVIATION (V)
LOAD CURRENT (mA)
–0.02
0.02
800
3014 G23
4
–0.04
0
0.04
6
2
0
200 400 600 1000
VIN = 7V
VOUT = 5V
CIN = COUT = 0.47μF CERAMIC
$ILOAD = 1mA TO 5mA
Minimum Input Voltage Load Regulation Output Noise Spectral Density
10Hz to 100kHz Output Noise Transient Response
LT3014
L7 LJUW
LT3014
7
3014fd
PIN FUNCTIONS
IN (Pin 1/Pin 8): Input. Power is supplied to the device
through the IN pin. A bypass capacitor is required on this
pin if the device is more than six inches away from the main
input fi lter capacitor. In general, the output impedance of
a battery rises with frequency, so it is advisable to include
a bypass capacitor in battery-powered circuits. A bypass
capacitor in the range of 0.1μF to 10μF is suffi cient. The
LT3014 is designed to withstand reverse voltages on the IN
pin with respect to ground and the OUT pin. In the case of
a reversed input, which can happen if a battery is plugged
in backwards, the LT3014 will act as if there is a diode in
series with its input. There will be no reverse current fl ow
into the LT3014 and no reverse voltage will appear at the
load. The device will protect both itself and the load.
GND (Pin 2/Pins 4, 9): Ground.
SHDN (Pin 3/Pin 5): Shutdown. The SHDN pin is used
to put the LT3014 into a low power shutdown state. The
output will be off when the SHDN pin is pulled low. The
SHDN pin can be driven either by 5V logic or open-collector
logic with a pull-up resistor. The pull-up resistor is only
required to supply the pull-up current of the open-collec-
tor gate, normally several microamperes. If unused, the
SHDN pin must be tied to IN or to a logic high.
ADJ (Pin 4/Pin 2): Adjust. This is the input to the error
amplifi er. This pin is internally clamped to ±7V. It has a
bias current of 4nA which fl ows into the pin (see curve
of ADJ Pin Bias Current vs Temperature in the Typical
Performance Characteristics). The ADJ pin voltage is
1.22V referenced to ground, and the output voltage range
is 1.22V to 60V.
OUT (Pin 5/Pin 1): Output. The output supplies power to
the load. A minimum output capacitor of 0.47μF is required
to prevent oscillations. Larger output capacitors will be
required for applications with large transient loads to limit
peak voltage transients. See the Applications Information
section for more information on output capacitance and
reverse output characteristics.
(SOT-23 Package/DD Package)
LT3014
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LT3014
8
3014fd
APPLICATIONS INFORMATION
The LT3014 is a 20mA high voltage low dropout regulator
with micropower quiescent current and shutdown. The
device is capable of supplying 20mA at a dropout voltage
of 350mV. The low operating quiescent current (7μA) drops
to 1μA in shutdown. In addition to the low quiescent cur-
rent, the LT3014 incorporates several protection features
which make it ideal for use in battery-powered systems.
The device is protected against both reverse input and
reverse output voltages. In battery backup applications
where the output can be held up by a backup battery
when the input is pulled to ground, the LT3014 acts like it
has a diode in series with its output and prevents reverse
current fl ow.
Adjustable Operation
The LT3014 has an output voltage range of 1.22V to 60V.
The output voltage is set by the ratio of two external
resistors as shown in Figure 1. The device servos the
output to maintain the voltage at the adjust pin at 1.22V
referenced to ground. The current in R1 is then equal to
1.22V/R1 and the current in R2 is the current in R1 plus
the ADJ pin bias current. The ADJ pin bias current, 4nA
at 25°C, fl ows through R2 into the ADJ pin. The output
voltage can be calculated using the formula in Figure 1.
The value of R1 should be less than 1.62M to minimize
errors in the output voltage caused by the ADJ pin bias
current. Note that in shutdown the output is turned off
and the divider current will be zero.
The device is tested
and specifi ed with the ADJ pin tied to the OUT pin and a
5μA DC load (unless otherwise specifi ed) for an output
voltage of 1.22V. Specifi cations for output voltages greater
than 1.22V will be proportional to the ratio of the desired
output voltage to 1.22V (VOUT/1.22V). For example, load
regulation for an output current change of 1mA to 20mA
is –13mV typical at VOUT = 1.22V. At VOUT = 12V, load
regulation is:
(12V/1.22V) • (–13mV) = –128mV
Output Capacitance and Transient Response
The LT3014 is designed to be stable with a wide range of
output capacitors. The ESR of the output capacitor affects
stability, most notably with small capacitors. A minimum
output capacitor of 0.47μF with an ESR of 3Ω or less is
recommended to prevent oscillations. The LT3014 is a
micropower device and output transient response will be
a function of output capacitance. Larger values of output
capacitance decrease the peak deviations and provide
improved transient response for larger load current
changes. Bypass capacitors, used to decouple individual
components powered by the LT3014, will increase the
effective output capacitor value.
Extra consideration must be given to the use of ceramic
capacitors. Ceramic capacitors are manufactured with a
variety of dielectrics, each with different behavior across
temperature and applied voltage. The most common
dielectrics used are specifi ed with EIA temperature char-
acteristic codes of Z5U, Y5V, X5R and X7R. The Z5U and
Y5V dielectrics are good for providing high capacitances
in a small package, but they tend to have strong voltage
and temperature coeffi cients as shown in Figures 2 and 3.
When used with a 5V regulator, a 16V 10μF Y5V capacitor
can exhibit an effective value as low as 1μF to 2μF for the
DC bias voltage applied and over the operating tempera-
ture range. The X5R and X7R dielectrics result in more
stable characteristics and are more suitable for use as the
output capacitor. The X7R type has better stability across
temperature, while the X5R is less expensive and is avail-
able in higher values. Care still must be exercised when
using X5R and X7R capacitors; the X5R and X7R codes
only specify operating temperature range and maximum
capacitance change over temperature. Capacitance change
due to DC bias with X5R and X7R capacitors is better than
Y5V and Z5U capacitors, but can still be signifi cant enough
to drop capacitor values below appropriate levels. Capaci-
tor DC bias characteristics tend to improve as component
case size increases, but expected capacitance at operating
voltage should be verifi ed.
Figure 1. Adjustable Operation
IN
LT3014
VIN
OUT
ADJ
GND
3014 F01
VOUT
R2
R1
+
R2
R1
VOUT = 1.22V
VADJ = 1.22V
IADJ = 4nA AT 25oC
OUTPUT RANGE = 1.22V TO 60V
+ (IADJ)(R2)1 +
•
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LT3014
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LT3014
9
3014fd
Figure 2. Ceramic Capacitor DC Bias Characteristics
Table 1. SOT-23 Measured Thermal Resistance
COPPER AREA
BOARD AREA
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)TOPSIDE BACKSIDE
2500 sq mm 2500 sq mm 2500 sq mm 125°C/W
1000 sq mm 2500 sq mm 2500 sq mm 125°C/W
225 sq mm 2500 sq mm 2500 sq mm 130°C/W
100 sq mm 2500 sq mm 2500 sq mm 135°C/W
50 sq mm 2500 sq mm 2500 sq mm 150°C/W
Voltage and temperature coeffi cients are not the only
sources of problems. Some ceramic capacitors have a
piezoelectric response. A piezoelectric device generates
voltage across its terminals due to mechanical stress, simi-
lar to the way a piezoelectric accelerometer or microphone
works. For a ceramic capacitor the stress can be induced
by vibrations in the system or thermal transients.
For surface mount devices, heat sinking is accomplished
by using the heat spreading capabilities of the PC board
and its copper traces. Copper board stiffeners and plated
through-holes can also be used to spread the heat gener-
ated by power devices.
The following table lists thermal resistance for several
different board sizes and copper areas. All measurements
were taken in still air on 3/32” FR-4 board with one ounce
copper.
APPLICATIONS INFORMATION
Figure 3. Ceramic Capacitor Temperature Characteristics
Table 2. DFN Measured Thermal Resistance
COPPER AREA
BOARD AREA
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)TOPSIDE BACKSIDE
2500 sq mm 2500 sq mm 2500 sq mm 40°C/W
1000 sq mm 2500 sq mm 2500 sq mm 45°C/W
225 sq mm 2500 sq mm 2500 sq mm 50°C/W
100 sq mm 2500 sq mm 2500 sq mm 62°C/W
For the DFN package, the thermal resistance junction-to-
case (θJC), measured at the Exposed Pad on the back of
the die, is 16°C/W.
DC BIAS VOLTAGE (V)
CHANGE IN VALUE (%)
3014 F02
20
0
–20
–40
–60
–80
–100 04810
26 12 14
X5R
Y5V
16
BOTH CAPACITORS ARE 16V,
1210 CASE SIZE, 10μF
TEMPERATURE (oC)
–50
40
20
0
–20
–40
–60
–80
–100
25 75
3014 F03
–25 0 50 100 125
Y5V
CHANGE IN VALUE (%)
X5R
BOTH CAPACITORS ARE 16V,
1210 CASE SIZE, 10μF
Thermal Considerations
The power handling capability of the device will be limited
by the maximum rated junction temperature (125°C). The
power dissipated by the device will be made up of two
components:
1. Output current multiplied by the input/output voltage
differential: IOUT • (VIN – VOUT) and,
2. GND pin current multiplied by the input voltage:
IGND • VIN.
The GND pin current can be found by examining the GND
Pin Current curves in the Typical Performance Character-
istics. Power dissipation will be equal to the sum of the
two components listed above.
The LT3014 regulator has internal thermal limiting de-
signed to protect the device during overload conditions.
For continuous normal conditions the maximum junction
temperature rating of 125°C must not be exceeded. It is
important to give careful consideration to all sources of
thermal resistance from junction to ambient. Additional
heat sources mounted nearby must also be considered.
LT3014
L7LJCUEN2
LT3014
10
3014fd
APPLICATIONS INFORMATION
Continuous operation at large input/output voltage dif-
ferentials and maximum load current is not practical
due to thermal limitations. Transient operation at high
input/output differentials is possible. The approximate
thermal time constant for a 2500sq mm 3/32" FR-4 board
with maximum topside and backside area for one ounce
copper is 3 seconds. This time constant will increase as
more thermal mass is added (i.e. vias, larger board, and
other components).
For an application with transient high power peaks, average
power dissipation can be used for junction temperature
calculations as long as the pulse period is signifi cantly less
than the thermal time constant of the device and board.
Calculating Junction Temperature
Example 1: Given an output voltage of 5V, an input volt-
age range of 24V to 30V, an output current range of 0mA
to 20mA, and a maximum ambient temperature of 50°C,
what will the maximum junction temperature be?
The power dissipated by the device will be equal to:
I
OUT(MAX) • (VIN(MAX) – VOUT) + (IGND • VIN(MAX))
where:
I
OUT(MAX) = 20mA
V
IN(MAX) = 30V
I
GND at (IOUT = 20mA, VIN = 30V) = 0.55mA
So:
P = 20mA • (30V – 5V) + (0.55mA • 30V) = 0.52W
The thermal resistance for the DFN package will be in the
range of 40°C/W to 62°C/W depending on the copper
area. So the junction temperature rise above ambient will
be approximately equal to:
0.52W • 50°C/W = 26°C
The maximum junction temperature will then be equal to
the maximum junction temperature rise above ambient
plus the maximum ambient temperature or:
TJMAX = 50°C + 26°C = 76°C
Example 2: Given an output voltage of 5V, an input voltage
of 48V that rises to 72V for 5ms(max) out of every 100ms,
and a 5mA load that steps to 20mA for 50ms out of every
250ms, what is the junction temperature rise above ambi-
ent? Using a 500ms period (well under the time constant
of the board), power dissipation is as follows:
P1(48V in, 5mA load) = 5mA • (48V – 5V)
+ (100μA • 48V) = 0.22W
P2(48V in, 20mA load) = 20mA • (48V – 5V)
+ (0.55mA • 48V) = 0.89W
P3(72V in, 5mA load) = 5mA • (72V – 5V)
+ (100μA • 72V) = 0.34W
P4(72V in, 20mA load) = 20mA • (72V – 5V)
+ (0.55mA • 72V) = 1.38W
Operation at the different power levels is as follows:
76% operation at P1, 19% for P2, 4% for P3, and
1% for P4.
P
EFF = 76%(0.22W) + 19%(0.89W) + 4%(0.34W)
+ 1%(1.38W) = 0.36W
With a thermal resistance in the range of 40°C/W to
62°C/W, this translates to a junction temperature rise
above ambient of 20°C.
LT3014
URRENT FLOWS fi»
mu DUTPUT Pm
L7 LJUW
LT3014
11
3014fd
Protection Features
The LT3014 incorporates several protection features which
make it ideal for use in battery-powered circuits. In ad-
dition to the normal protection features associated with
monolithic regulators, such as current limiting and thermal
limiting, the device is protected against reverse-input volt-
ages, and reverse voltages from output to input.
Current limit protection and thermal overload protection
are intended to protect the device against current overload
conditions at the output of the device. For normal operation,
the junction temperature should not exceed 125°C.
The input of the device will withstand reverse voltages
of 80V. Current fl ow into the device will be limited to less
than 6mA (typically less than 100μA) and no negative
voltage will appear at the output. The device will protect
both itself and the load. This provides protection against
batteries which can be plugged in backward.
The ADJ pin can be pulled above or below ground by as
much as 7V without damaging the device. If the input is
left open circuit or grounded, the ADJ pin will act like an
open circuit when pulled below ground, and like a large
resistor (typically 100k) in series with a diode when pulled
above ground. If the input is powered by a voltage source,
pulling the ADJ pin below the reference voltage will cause
the device to current limit. This will cause the output to go
to an unregulated high voltage. Pulling the ADJ pin above
the reference voltage will turn off all output current.
In situations where the ADJ pin is connected to a resistor
divider that would pull the ADJ pin above its 7V clamp volt-
age if the output is pulled high, the ADJ pin input current
must be limited to less than 5mA. For example, a resistor
divider is used to provide a regulated 1.5V output from the
1.22V reference when the output is forced to 60V. The top
resistor of the resistor divider must be chosen to limit the
current into the ADJ pin to less than 5mA when the ADJ
pin is at 7V. The 53V difference between the OUT and ADJ
pins divided by the 5mA maximum current into the ADJ
pin yields a minimum top resistor value of 10.6k.
In circuits where a backup battery is required, several
different input/output conditions can occur. The output
voltage may be held up while the input is either pulled
to ground, pulled to some intermediate voltage, or is left
open circuit. Current fl ow back into the output will follow
the curve shown in Figure 4. The rise in reverse output
current above 7V occurs from the breakdown of the 7V
clamp on the ADJ pin. With a resistor divider on the
regulator output, this current will be reduced depending
on the size of the resistor divider.
When the IN pin of the LT3014 is forced below the OUT
pin or the OUT pin is pulled above the IN pin, input cur-
rent will typically drop to less than 2μA. This can happen
if the input of the LT3014 is connected to a discharged
(low voltage) battery and the output is held up by either
a backup battery or a second regulator circuit. The state
of the SHDN pin will have no effect on the reverse output
current when the output is pulled above the input.
APPLICATIONS INFORMATION
Figure 4. Reverse Output Current
OUTPUT VOLTAGE (V)
0
REVERSE OUTPUT CURRENT (μA)
50
45
40
30
35
25
20
15
10
5
08
3014 F04
21357946 10
TJ = 25oC
VIN = 0V
VOUT = VADJ
CURRENT FLOWS
INTO OUTPUT PIN
ADJ PIN
ESD CLAMP
LT3014
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J —‘[>°_i% E
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L7LJCUEN2
LT3014
12
3014fd
TYPICAL APPLICATIONS
5V Buck Converter with Low Current Keep Alive Backup
Buck Converter
Effi ciency vs Load Current
BOOST
VIN
6
2
10
12
D1
10MQ060N
R1
15.4k
VOUT
5V
1A/20mA
4
15
14
11
CC
1nF
FOR INPUT VOLTAGES BELOW 7.5V,
SOME RESTRICTIONS MAY APPLY
INCREASE L1 TO 30μH FOR LOAD
CURRENTS ABOVE 0.6A AND TO
60μH ABOVE 1A
1, 8, 9, 16
LT1766
SHDN
SYNC
SW
BIAS
FB
VC
GND
C2
0.33μF
C1
100μF 10V
SOLID
TANTALUM
L1†
15μH
D2
D1N914
R2
4.99k
3014 TA03
C3
4.7μF
100V
CERAMIC
VIN
5.5V*
TO 60V
+
ADJ
3.92M
1.27M
OUTIN
SHDN
LT3014
GND
OPERATING
CURRENT
HIGH
LOW
*
†
LOAD CURRENT (A)
0
EFFICIENCY (%)
80
90
100
1.00
3014 TA04
70
60
50 0.25 0.50 0.75 1.25
VIN = 10V
VIN = 42V
VOUT = 5V
L = 68μH
LT3014
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LT3014
13
3014fd
TYPICAL APPLICATIONS
LT3014 Automotive Application
LT3014 Telecom Application
Constant Brightness for Indicator LED over Wide Input Voltage Range
+
ADJ
OUTIN
SHDN
LT3014
GND
ON
OFF
1μF 1μF
VIN
12V
(LATER 42V) LOAD: CLOCK,
SECURITY SYSTEM
ETC
+
–
ADJ
OUTIN
SHDN
LT3014
GND
ON
OFF
1μF 1μF
VIN
48V
(72V TRANSIENT)
LOAD:
SYSTEM MONITOR
ETC
NO PROTECTION
DIODE NEEDED!
NO PROTECTION
DIODE NEEDED!
3014 TA05
BACKUP
BATTERY
R1
R2
R1
R2
IN
LT3014
SHDN
1μF
RETURN
OFF ON
–48V
OUT
ADJ
GND
3014 TA06
1μF
RSET
ILED = 1.22V/RSET
–48V CAN VARY FROM –3.3V TO –80V
LT3014
L7LJCUEN2
LT3014
14
3014fd
PACKAGE DESCRIPTION
S5 Package
5-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1635)
1.50 – 1.75
(NOTE 4)
2.80 BSC
0.30 – 0.45 TYP
5 PLCS (NOTE 3)
DATUM ‘A’
0.09 – 0.20
(NOTE 3) S5 TSOT-23 0302 REV B
PIN ONE
2.90 BSC
(NOTE 4)
0.95 BSC
1.90 BSC
0.80 – 0.90
1.00 MAX
0.01 – 0.10
0.20 BSC
0.30 – 0.50 REF
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. JEDEC PACKAGE REFERENCE IS MO-193
3.85 MAX
0.62
MAX
0.95
REF
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
1.4 MIN
2.62 REF
1.22 REF
LT3014
7 i
x U ML?
,,,\,,, * "W47, ,
\T + \ Jr
‘0 \ H mm}
L, ii a «4‘
V 77
L7 LJUW
LT3014
15
3014fd
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
PACKAGE DESCRIPTION
DD Package
8-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1698)
3.00 p0.10
(4 SIDES)
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON TOP AND BOTTOM OF PACKAGE
0.38 p 0.10
BOTTOM VIEW—EXPOSED PAD
1.65 p 0.10
(2 SIDES)
0.75 p0.05
R = 0.115
TYP
2.38 p0.10
(2 SIDES)
14
85
PIN 1
TOP MARK
(NOTE 6)
0.200 REF
0.00 – 0.05
(DD) DFN 1203
0.25 p 0.05
2.38 p0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
1.65 p0.05
(2 SIDES)2.15 p0.05
0.50
BSC
0.675 p0.05
3.5 p0.05
PACKAGE
OUTLINE
0.25 p 0.05
0.50 BSC
LT3014
L7HCUEM
LT3014
16
3014fd
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2005
LT 0808 REV D • PRINTED IN USA
RELATED PARTS
PART NUMBER DESCRIPTION COMMENTS
LT1129 700mA, Micropower, LDO VIN: 4.2V to 30V, VOUT(MIN) = 3.75V, VDO = 0.4V, IQ = 50μA, ISD = 16μA,
DD, SOT-223, S8, TO220, TSSOP-20 Packages
LT1175 500mA, Micropower Negative LDO VIN: –20V to –4.3V, VOUT(MIN) = –3.8V, VDO = 0.50V, IQ = 45μA, ISD = 10μA,
DD, SOT-223, S8 Packages
LT1185 3A, Negative LDO VIN: –35V to –4.2V, VOUT(MIN) = –2.40V, VDO = 0.80V, IQ = 2.5mA, ISD <1μA,
TO220-5 Package
LT1761 100mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 20μA, ISD <1μA,
ThinSOT Package
LT1762 150mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 25μA, ISD <1μA,
MS8 Package
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S8 Package
LT1764/LT1764A 3A, Low Noise, Fast Transient Response, LDO VIN: 2.7V to 20V, VOUT(MIN) = 1.21V, VDO = 0.34V, IQ = 1mA, ISD <1μA,
DD, TO220 Packages
LTC1844 150mA, Very Low Dropout LDO VIN: 1.6V to 6.5V, VOUT(MIN) = 1.25V, VDO = 0.08V, IQ = 40μA, ISD <1μA,
ThinSOT Package
LT1962 300mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.27V, IQ = 30μA, ISD <1μA,
MS8 Package
LT1963/LT1963A 1.5A, Low Noise, Fast Transient Response, LDO VIN: 2.1V to 20V, VOUT(MIN) = 1.21V, VDO = 0.34V, IQ = 1mA, ISD <1μA,
DD, TO220, SOT Packages
LT1964 200mA, Low Noise Micropower, Negative LDO VIN: –1.9V to –20V, VOUT(MIN) = –1.21V, VDO = 0.34V, IQ = 30μA, ISD = 3μA,
ThinSOT Package
LT3010 50mA, 80V, Low Noise Micropower, LDO VIN: 3V to 80V, VOUT(MIN) = 1.28V, VDO = 0.3V, IQ = 30μA, ISD <1μA,
MS8E Package
LT3020 100mA, Low VIN, Low VOUT Micropower, VLDO VIN: 0.9V to 10V, VOUT(MIN) = 0.20V, VDO = 0.15V, IQ = 120μA, ISD <1μA,
DFN, MS8 Packages
LT3023 Dual 100mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 40μA, ISD <1μA,
DFN, MS10 Packages
LT3024 Dual 100mA/500mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 60μA, ISD <1μA,
DFN, TSSOP-16E Packages
LT3027 Dual 100mA, Low Noise LDO with Independent
Inputs
VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 40μA, ISD <1μA,
DFN, MS10E Packages
LT3028 Dual 100mA/500mA, Low Noise LDO with
Independent Inputs
VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 60μA, ISD <1μA,
DFN, TSSOP-16E Packages
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