Features

• High Voltage Operation: Up to 60V
• Synchronizable Up to 600kHz
• Adjustable Constant Frequency: 100kHz to 500kHz
• Output Voltages Up to 36V
• Stable Operation in Current Limit
• Adaptive Nonoverlap Circuitry Prevents Switch Shoot-Through
• Reverse Inductor Current Inhibit for Discontinuous Operation Improves Efficiency with Light Loads
• Programmable Soft-Start
• 120μA No Load Quiescent Current
• 10μA Shutdown Supply Current
• 1% Regulation Accuracy
• Standard Gate N-Channel Power MOSFETs
• Reverse Overcurrent Protection
• 16-Lead Thermally Enhanced TSSOP Package

Typical Application

Description

The LT3845A is a high voltage, synchronous, current mode controller used for medium to high power, high efficiency supplies. It offers a wide 4V to 60V input range (7.5V minimum start-up voltage). An onboard regulator simplifies the biasing requirements by providing IC power directly from V_IN.

Burst Mode® operation maintains high efficiency at light loads by reducing IC quiescent current to 120μA. Light load efficiency is also improved with the reverse inductor current inhibit function which supports discontinuous operation.

Additional features include adjustable fixed operating frequency that can be synchronized to an external clock for noise sensitive applications, gate drivers capable of driving large N-channel MOSFETs, a precision undervoltage lockout, 10μA shutdown current, short-circuit protection and a programmable soft-start.

The LT3845A is available in a 16-lead thermally enhanced TSSOP package.