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LT1676

Wide Input Range,

High Efficiency, Step-Down

Switching Regulator

s

Wide Input Range: 7.4V to 60V

s

700mA Peak Switch Current 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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100kHz Fixed Operating Frequency

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Synchronizable to 250kHz

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Low Supply Current in Shutdown: 30

µA

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Available in 8-Pin SO and PDIP Packages

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Automotive DC/DC Converters

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Telecom 48V Step-Down Converters

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Cellular Phone Battery Charger Accessories

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IEEE 1394 Step-Down Converters

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 offers excellent dynamic input supply rejec-

tion and short-circuit protection.

The LT1676 contains several features to enhance effi-

ciency. The internal control circuitry is normally powered

action of the LT1676 switch circuitry is also load depen-

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

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

rise time is deliberately reduced to avoid pulse skipping

behavior.

The available SO-8 package and 100kHz switching fre-

quency allow for minimal PC board area requirements.

Figure 1

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

39

µF

63V

1676 F01

LT1676

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

220

µH*

2200pF

8V TO 50V

100pF

*65T #30 ON MAGNETICS

MPP #55030

1

60

70

80

90

10

100

1000

1676 TA01

50

40

30

20

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO