LTC3803-3

The LTC^®3803-3 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 LTC3803-3 provides ±1.5% output voltage accuracy and consumes only 240A of quiescent current. Groundreferenced current sensing allows LTC3803-3-based converters to accept input supplies beyond the LTC3803-3'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 VIN through a resistor, due to its internal 9.4V shunt regulator. An internal undervoltage lockout shuts down the LTC3803-3 when the input voltage falls below 4.4V, guaranteeing at least 4.4V of gate drive to the external MOSFET.

The LTC3803-3 is available in a low profile (1mm) 6-lead SOT-23 (ThinSOTTM) package.