LT1529

Manufacturer Part NumberLT1529
Description3A Low Dropout Regulators with Micropower Quiescent Current and Shutdown
ManufacturerLINER [Linear Technology]
LT1529 datasheet
 
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FEATURES
Dropout Voltage: 0.6V at I
= 3A
OUT
Output Current: 3A
Quiescent Current: 50 A
No Protection Diodes Needed
Adjustable Output from 3.8V to 14V
3.3V and 5V Fixed Output Voltages
Controlled Quiescent Current in Dropout
Shutdown I
= 16 A
Q
Stable with 3.3 F Output Capacitor
Reverse Battery Protection
No Reverse Current
Thermal Limiting
U
APPLICATIO S
High Efficiency Regulator
Regulator for Battery-Powered Systems
Post Regulator for Switching Supplies
5V to 3.3V Logic Regulator
U
TYPICAL APPLICATIO
5V Supply with Shutdown
5
1
V
OUTPUT
IN
LT1529-5
V
> 5.5V
IN
4
2
SHDN
SENSE
GND
3
V
(PIN 4)
OUTPUT
SHDN
< 0.25
OFF
> 2.8
ON
NC
ON
3A Low Dropout Regulators
DESCRIPTIO
®
The LT
1529/LT1529-3.3/LT1529-5 are 3A low dropout
regulators with micropower quiescent current and shut-
down. The devices are capable of supplying 3A of output
current with a dropout voltage of 0.6V. Designed for use
in battery-powered systems, the low quiescent current,
50 A operating and 16 A in shutdown, make them an
ideal choice. The quiescent current is well controlled; it
does not rise in dropout as it does with many other low
dropout PNP regulators.
Other features of the LT1529 /LT1529-3.3/LT1529-5 in-
clude the ability to operate with small output capacitors.
They are stable with only 3.3 F on the output while most
older devices require between 10 F and 100 F for stabil-
ity. Small ceramic capacitors can be used, enhancing
manufacturabiltiy. Also the input may be connected to
voltages lower than the output voltage, including negative
voltages, without reverse current flow from output to
input. This makes the LT1529/LT1529-3.3/LT1529-5 ideal
for backup power situations where the output is held high
and the input is at ground or reversed. Under these
conditions, only 16 A will flow from the OUTPUT pin to
ground. The devices are available in 5-lead TO-220 and
5-lead DD packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
0.6
0.5
5V
0.4
+
3A
3.3 F
SOLID
0.3
TANT
0.2
0.1
0
LT1529 • TA01
LT1529
LT1529-3.3/LT1529-5
with Micropower
Quiescent Current
and Shutdown
U
Dropout Voltage
0
1.0
1.5
2.0
2.5
3.0
0.5
OUTPUT CURRENT (A)
LT1529 • TA02
1

LT1529 Summary of contents

  • Page 1

    ... The quiescent current is well controlled; it does not rise in dropout as it does with many other low dropout PNP regulators. Other features of the LT1529 /LT1529-3.3/LT1529-5 in- clude the ability to operate with small output capacitors. They are stable with only 3 the output while most older devices require between 10 F and 100 F for stabil- ity ...

  • Page 2

    ... SHDN TAB IS 3 GND GND 2 SENSE/ADJ* 1 OUTPUT Q PACKAGE 5-LEAD PLASTIC DD PAK *PIN 2 = SENSE FOR LT1529-3.3/LT1529-5 = ADJ FOR LT1529 T = 125 JMAX JA Consult factory for Military grade parts. ELECTRICAL C HARA TERISTICS C The denotes specifications which apply over the operating temperature range, otherwise specificatons are at T ...

  • Page 3

    ... When operating at maximum output current the input voltage range must be limited. Note 5: The LT1529 is tested and specified with the ADJ pin connected to the OUTPUT pin. Note 6: Dropout voltage is the minimum input/output voltage required to maintain regulation at the specified output current ...

  • Page 4

    ... LT1529 • G04 LT1529-3.3 Output Voltage 3.400 I = 1mA LOAD 3.375 3.350 3.325 3.300 3.275 3.250 3.225 3.200 – 50 – 100 TEMPERATURE ( C) LT1529 • G07 HARA TERISTICS C Dropout Voltage 0 100mA LOAD LOAD 1. 10mA 0.7 LOAD LOAD 700mA ...

  • Page 5

    ... TEMPERATURE ( C) LT1529 • G17 R = 7.5 LOAD I = 500mA* LOAD R = 12.5 LOAD I = 300mA* LOAD LOAD I = 100mA* LOAD LT1529 • G12 R = 1.25 LOAD I = 3A* LOAD R = 5.3 LOAD I = 700mA* LOAD R = 2.5 LOAD I = 1.5A* LOAD LT1529 • G15 = 3A = 1mA 75 100 125 LT1529 • G18 5 ...

  • Page 6

    ... I = 1.5A OUT (NOMINAL OUT + 50mV RIPPLE RMS OUT 30 SOLID TANT 125 10 100 1k FREQUENCY (Hz) LT1529 • G26 75 100 125 LT1529 • G21 100 125 75 LT1529 • G24 OUT SOLID TANT = 3.3 F 10k 100k LT1529 • G27 ...

  • Page 7

    ... SENSE (Pin 2): SENSE Pin. For fixed voltage versions of the LT1529 (LT1529-3.3, LT1529-5) the SENSE pin is the input to the error amplifier. Optimum regulation will be obtained at the point where the SENSE pin is connected to the output pin. For most applications the SENSE pin is connected directly to the OUTPUT pin at the regulator ...

  • Page 8

    ... OUTPUT pin. In the IN case of a reversed input, which can happen if a battery is plugged in backwards, the LT1529 will act as if there is a diode in series with its input. There will be no reverse current flow into the LT1529 and no reverse voltage will appear at the load ...

  • Page 9

    ... T JMAX Output Capacitance and Transient Performance The LT1529 is designed to be stable with a wide range of output capacitors. The minimum recommended value is 3.3 F with an ESR of 2 LT1529 LT1529-3.3/LT1529-5 THERMAL RESISTANCE ...

  • Page 10

    ... Larger values of output capacitance will decrease the peak deviations and provide improved output transient re- sponse for larter load current deltas. Bypass capacitors, used to decouple individual components powered by the LT1529, will increase the effective value of the output capacitor. Protection Features The LT1529 incorporates several protection features which make it ideal for use in battery-powered circuits ...

  • Page 11

    ... The state of the SHDN pin will have no effect on the reverse output current when the V floating. When the input of the LT1529 is forced to a voltage below its nominal output voltage and its output is held high, the output current will follow the curve shown in Figure 3 . This ...

  • Page 12

    ... LT1529 LT1529-3.3/LT1529-5 PACKAGE DESCRIPTIO 0.390 – 0.415 (9.906 – 10.541) 0.460 – 0.500 (11.684 – 12.700) 0.057 – 0.077 0.028 – 0.038 (1.448 – 1.956) (0.711 – 0.965) RELATED PARTS PART NUMBER DESCRIPTION LT1120A 125mA Low Dropout Regulator with ® ...