High Voltage, 3A, 200kHz Step-Down Switching Regulator

The LT3430/LT3430-1 are monolithic buck switching regulators that accept input voltages up to 60V. A high efficiency 3A, 0.1Ω switch is included on the die along with all the necessary oscillator, control and logic circuitry. A current mode architecture provides fast transient response and excellent loop stability.

Special design techniques and a new high voltage process achieve high efficiency over a wide input range. Efficiency is maintained over a wide output current range by using the output to bias the circuitry and by utilizing a supply boost capacitor to saturate the power switch. Patented circuitry* maintains peak switch current over the full duty cycle range. A shutdown pin reduces supply current to 30µA and a SYNC pin can be externally synchronized with a logic level input from 228kHz to 700kHz for the LT3430 or from 125kHz to 250kHz for the LT3430-1.

The LT3430/LT3430-1 are available in a thermally enhanced 16-pin TSSOP package.

Applications

* Industrial and Automotive Power Supplies

* Portable Computers

* Battery Chargers

* Distributed Power Systems

* Wide Input Range: 5.5V to 60V

* 3A Peak Switch Current over All Duty Cycles

* Constant Switching Frequency:

* 200kHz (LT3430)

* 100kHz (LT3430-1)

* 0.1Ω Switch Resistance

* Current Mode

* Effective Supply Current: 2.5mA

* Shutdown Current: 30µA

* 1.2V Feedback Reference Voltage

* Easily Synchronizable

* Cycle-by-Cycle Current Limiting

* Small, 16-Pin Thermally Enhanced TSSOP Package