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LT1776

Wide Input Range,

High Efficiency, Step-Down

Switching Regulator

The LT

(step-down) switching regulator. The monolithic die in-

cludes all oscillator, control and protection circuitry. The

part can accept input voltages as high as 60V and contains

an output switch rated at 700mA peak current. Current

mode control delivers excellent dynamic input supply

rejection and short-circuit protection.

The LT1776 contains several features to enhance effi-

ciency. The internal control circuitry is normally powered

action of the LT1776 switch circuitry is also load depen-

dent. At medium to high loads, the output switch circuitry

maintains fast rise time for good efficiency. At light loads,

rise time is deliberately reduced to avoid pulse skipping

behavior.

The available SO-8 package and 200kHz switching fre-

quency allow for minimal PC board area requirements.

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Wide Input Range: 7.4V to 40V

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Tolerates Input Transients to 60V

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700mA Peak Switch Rating

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Adaptive Switch Drive Maintains Efficiency at High

Load Without Pulse Skipping at Light Load

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True Current Mode Control

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200kHz Fixed Operating Frequency

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Synchronizable to 400kHz

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Low Supply Current in Shutdown: 30

µA

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Available in 8-Pin SO and PDIP Packages

39

µF

63V

1776 F01

LT1776

FB

SHDN

SYNC

2

5

4

3

7

8

1

6

GND

+

100

µF

10V

+

MBR160

36.5k

1%

5V

400mA

12.1k

1%

22k

100

µH*

2200pF

8V TO 40V

100pF

*43T #30 ON MAGNETICS

MPP #55030

LOAD CURRENT (mA)

1

60

70

80

90

10

100

1000

1776 TA01

50

40

30

20

Figure 1

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

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Automotive DC/DC Converters

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Cellular Phone Battery Charger Accessories

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IEEE 1394 Step-Down Converters

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO