Features

• Wide 4V to 60V Input Voltage Range
• Output Voltages up to 36V
• Adaptive Nonoverlap Circuitry Prevents Switch Shoot-Through
• Reverse Inductor Current Inhibit for Discontinuous Operation Improves Efficiency with Light Loads
• Output Slew Rate Controlled Soft-Start with Auto-Reset
• 100µA No Load Quiescent Current
• Low 10µA Current Shutdown
• 1% Regulation Accuracy
• 200kHz Operating Frequency
• Standard Gate N-Channel Power MOSFETs
• Current Limit Unaffected by Duty Cycle
• Reverse Overcurrent Protection
• 16-Lead Thermally Enhanced TSSOP Package

Typical Application

Description

The LT3800 is a 200kHz fixed frequency high voltage synchronous current mode step-down switching regulator controller. The IC drives standard gate N-channel power MOSFETs and can operate with input voltages from 4V to 60V. An onboard regulator provides IC power directly from V_IN and provides for output-derived power to minimize V_IN quiescent current. MOSFET drivers employ an internal dynamic bootstrap feature, maximizing gate-source "ON" voltages during normal operation for improved operating efficiencies. The LT3800 incorporates Burst Mode operation, which reduces no load quiescent current to under 100µA. Light load efficiencies are also improved through a reverse inductor current inhibit, allowing the controller to support discontinuous operation. Both Burst Mode operation and the reverse-current inhibit features can be disabled if desired. The LT3800 incorporates a programmable soft-start that directly controls the voltage slew rate of the converter output for reduced startup surge currents and overshoot errors. The LT3800 is available in a 16-lead thermally enhanced TSSOP package.

Protected by U.S. Patents, including 5481178, 6611131, 6304066, 6498466, 6580258.