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