Features

• Wide Input Range: 5.5V to 60V
• 3A Peak Switch Current
• Small Thermally Enhanced 16-Pin TSSOP Package
• Constant 500kHz Switching Frequency
• Saturating Switch Design: 0.1 Ohm
• Peak Switch Current Maintained Over Full Duty Cycle Range
• Effective Supply Current: 2.5mA
• Shutdown Current: 30µA
• 1.2V Feedback Reference Voltage
• Easily Synchronizable
• Cycle-by-Cycle Current Limiting

Typical Application

Description

The LT3431 is a 500kHz monolithic buck switching regulator that accepts input voltages up to 60V. A high efficiency 3A, 0.1 Ohm 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 good 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 the device can be externally synchronized from 580kHz to 700kHz with logic level inputs.

The LT3431 is available in a thermally enhanced 16-pin TSSOP package.