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DESCRIPTION

The LTC?3646 is a high efficiency, step-down DC/DC

converter with internal high side and synchronous power

FETs. It draws only 140¦ÌA typical DC supply current in

Burst Mode operation at no load while maintaining output

voltage regulation.

The LTC3646 can supply up to a 1A load, and its combination

of Burst Mode operation, integrated power switches

and low quiescent current provides high efficiency over a

broad range of load currents. Alternatively, it can be used

in forced continuous mode for ripple sensitive applications.

The LTC3646 has a wide 4.0V to 40V input range and its

patented controlled on-time architecture and 0.6V reference

voltage allow for large step-down ratios without

the risk of output overvoltage. The frequency may be set

between 200kHz and 3.0MHz with a program resistor or

synchronized to an external clock.

The internal soft-start, short-circuit protection and voltage

rating make the LTC3646 a robust part ideal for high

voltage applications.

FEATURES

- Wide Input Voltage Range: 4.0V to 40V

- 1A Guaranteed Output Current

- High Efficiency: Up to 95

- Wide Output Voltage Range

- LTC3646: 2.0V to 30V

- LTC3646-1: 0.6V to 15V

- ¡À1 Accurate Reference Voltage

- Internal or External Compensation

- Switching Frequency Adjustable and Synchronizable:

200kHz to 3MHz

- Selectable High Efficiency Burst Mode? Operation or

Forced Continuous Mode

- 14 Lead 3mm ¡Á 4mm DFN or Thermally Enhanced

16-Lead MSOP Packages

APPLICATIONS

- Point of Load Power Supplies

- Intermediate Bus Power

- Automotive Applications