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LT1373

250kHz Low Supply Current

High Efficiency

1.5A Switching Regulator

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Boost Regulators

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CCFL Backlight Driver

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Laptop Computer Supplies

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Multiple Output Flyback Supplies

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Inverting Supplies

The LT

current mode switching regulator. It can be operated in all

standard switching configurations including boost, buck,

flyback, forward, inverting and “Cuk.” A 1.5A high effi-

ciency switch is included on the die, along with all oscilla-

tor, control and protection circuitry. All functions of the

LT1373 are integrated into 8-pin SO/PDIP packages.

Compared to the 500kHz LT1372, which draws 4mA of

quiescent current, the LT1373 switches at 250kHz, typi-

cally consumes only 1mA and has higher efficiency. High

frequency switching allows for small inductors to be used.

All surface mount components consume less than 0.6

square inch of board space.

New design techniques increase flexibility and maintain

ease of use. Switching is easily synchronized to an exter-

nal logic level source. A logic low on the shutdown pin

reduces supply current to 12

µA. Unique error amplifier

circuitry can regulate positive or negative output voltage

while maintaining simple frequency compensation tech-

niques. Nonlinear error amplifier transconductance re-

duces output overshoot on start-up or overload recovery.

Oscillator frequency shifting protects external compo-

nents during overload conditions.

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Uses Small Inductors: 15

µH

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All Surface Mount Components

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Only 0.6 Square Inch of Board Space

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Low Minimum Supply Voltage: 2.7V

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Constant Frequency Current Mode

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Current Limited Power Switch: 1.5A

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Regulates Positive or Negative Outputs

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Shutdown Supply Current: 12

µA Typ

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Easy External Synchronization

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8-Pin SO or PDIP Packages

, LTC and LT are registered trademarks of Linear Technology Corporation.

OUTPUT CURRENT (mA)

1

70

80

90

10

100

1000

LT1373 • TA02

60

50

100

f = 250kHz

LT1373

5V

1

2

8

5

4

6, 7

SUMIDA CD75-220KC (22

µH) OR

COILCRAFT D03316-153 (15

µH)

AVX TPSD226M025R0200

GND

FB

LT1373 • TA01

S/S

L1*

22

µH

C1**

22

µF

C4**

22

µF

C2

0.01

µF

R3

5k

R2

24.9k

1%

R1

215k

1%

*

**

†

12V

D1

MBRS120T3

ON

OFF

L1

15

µH

22

µH

0.3A

0.35A

+

+

5V-to-12V Boost Converter

12V Output Efficiency

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO