1

LT1372/LT1377

500kHz and 1MHz

High Efficiency

1.5A Switching Regulators

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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

switching regulators. They can be operated in all standard

switching configurations including boost, buck, flyback,

forward, inverting and “Cuk.” A 1.5A high efficiency switch

is included on the die, along with all oscillator, control and

protection circuitry. All functions of the LT1372/LT1377

are integrated into 8-pin SO/PDIP packages.

The LT1372/LT1377 typically consumes only 4mA quies-

cent current and has higher efficiency than previous parts.

High frequency switching allows for very small inductors

to be used. All surface mount components consume less

than 0.5 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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Faster Switching with Increased Efficiency

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Uses Small Inductors: 4.7

µH

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All Surface Mount Components

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Only 0.5 Square Inch of Board Space

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Low Minimum Supply Voltage: 2.7V

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Quiescent Current: 4mA Typ

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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

FEATURES

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

12V Output Efficiency

OUTPUT CURRENT (A)

0.01

50

60

70

80

90

0.1

1

LT1372 • TA02

100

5V-to-12V Boost Converter

LT1372/LT1377

5V

1

2

8

5

4

6, 7

GND

FB

LT1372 • TA01

S/S

L1*

4.7

µH

C1**

22

µF

C4**

22

µF

C2

0.047

µF

C3

0.0047

µF

R3

2k

R2

6.19k

1%

R1

53.6k

1%

†

12V

D1

MBRS120T3

ON

OFF

*COILCRAFT DO1608-472 (4.7

µH) OR

COILCRAFT DT3316-103 (10

µH) OR

SUMIDA CD43-4R7 (4.7

µH) OR

SUMIDA CD73-100KC (10

µH) OR

**AVX TPSD226M025R0200

L1

4.7

µH

10

µH

0.25A

0.35A

+

+