PSR flyback converter offers a simple, reliable and high-density design

Texas Instruments LM5180-Q1 Primary-Side Regulated Flyback Converter comes with high efficiency over a wide input voltage range of 4.5V to 65V. The isolated output voltage is sampled via the primary-side flyback voltage, removing the requirement for an optocoupler, voltage reference, or third winding from the transformer for output voltage regulation. The high level of integration provides a simple, reliable and high-density design with just one component crossing the isolation barrier. Boundary conduction mode switching allows a compact magnetic solution and better than ±1.5% load and line regulation performance. An integrated 100V power MOSFET gives output power up to 7W with enhanced headroom for line transients.

The converter simplifies the implementation of isolated DC-DC supplies with arbitrary features to optimise performance for the target end equipment. The output voltage is set by one resistor, whilst an optional resistor increases output voltage accuracy by negating the thermal coefficient of the flyback diode voltage drop. Further features offer an internally-fixed or externally-programmable soft start, precision enable input with hysteresis for adjustable line UVLO, optional bias supply connection for higher efficiency, hiccup-mode overload protection, and thermal shutdown protection with automatic recovery.

Typical applications cover automotive body electronics, automotive powertrain systems, and isolated bias power rails.