LT3798 Datasheet

• Isolated PFC Flyback with Minimum Number of External Components
• V_IN and V_OUT Limited Only by External Components
• Active Power Factor Correction
• Low Harmonic Distortion
• No Opto-Coupler Required
• Constant-Current and Constant-Voltage Regulation
• Accurate Regulated Voltage and Current (±5% Typical)
• Energy Star Compliant (<0.5W No Load Operation)
• Thermally Enhanced 16-lead MSOP Package

• Offline 5W to 100W+ Applications
• High DC V_IN Isolated Applications
• Offline Bus Converter (12V, 24V or 48V Outputs)

The LT3798 is a constant-voltage/constant-current isolated flyback controller that combines active power factor correction (PFC) with no opto-coupler required for output voltage feedback into a single-stage converter. A LT3798 based design can achieve a power factor of greater than 0.97 by actively modulating the input current, allowing compliance with most Harmonic Current Emission requirements.

The LT3798 is well suited for a wide variety of off-line applications. The input range can be scaled up or down, depending mainly on the choice of external components. Efficiencies higher than 86% can be achieved with output power levels up to 100W. In addition, the LT3798 can easily be designed into high DC input applications.