LTC3803

The LTC^®3803 is a constant frequency current mode flyback controller optimized for driving 6V-rated N-channel MOSFETs in high input voltage applications. Constant frequency operation is maintained down to very light loads, resulting in less low frequency noise generation over a wide range of load currents. Slope compensation can be programmed with an external resistor.

The LTC3803 provides ±1.5% output voltage accuracy and consumes only 240A of quiescent current. Groundreferenced current sensing allows LTC3803-based converters to accept input supplies beyond the LTC3803's absolute maximum V_CC. A micropower hysteretic start-up feature allows efficient operation at high input voltages. For simplicity, the device can also be powered from a high V_IN through a resistor, due to its internal 9.4V shunt regulator. An internal undervoltage lockout shuts down the LTC3803 when the input voltage falls below 4.6V, guaranteeing at least 4.6V of gate drive to the external MOSFET.

The LTC3803 is available in a low profile (1mm) 6-lead SOT-23 (ThinSOT^TM) package.