DESCRIPTION

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

converter with internal high side and synchronous power

FETs. It draws only 140μA 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

- ±1 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 × 4mm DFN or Thermally Enhanced

16-Lead MSOP Packages

APPLICATIONS

- Point of Load Power Supplies

- Intermediate Bus Power

- Automotive Applications