5.5V to 60V 1.5A, 200kHz Step-Down Switching Regulator

The LT1766/LT1766-5 are 200kHz monolithic buck switching regulators that accept input voltages up to 60V. A high efficiency 1.5A, 0.2Ω switch is included on the die along with all the necessary oscillator, control and logic circuitry. A current mode control architecture delivers 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 25μA and the device can be externally synchronized from 228kHz to 700kHz with logic-level inputs.

The LT1766/LT1766-5 are available in a 16-pin fused-lead SSOP package or a TSSOP package with exposed backside for improved thermal performance.

Applications

* High Voltage, Industrial and Automotive

* Portable Computers

* Battery-Powered Systems

* Battery Chargers

* Distributed Power Systems

* Wide Input Range: 5.5V to 60V

* 1.5A Peak Switch Current

* Constant 200kHz Switching Frequency

* Saturating Switch Design: 0.2Ω

* Peak Switch Current Rating Maintained Over Full Duty Cycle Range

* Low Effective Supply Current: 2.5mA

* Low Shutdown Current: 25μA

* 1.2V Feedback Reference Voltage (LT1766)

* 5V Fixed Output (LT1766-5)

* Easily Synchronizable

* Cycle-by-Cycle Current Limiting

* Small 16-Pin SSOP and Thermally Enhanced TSSOP Packages