LM25180 PSR Flyback Converter with 65 V, 1.5 A Integrated Power MOSFET

Texas Instruments' LM25180 is a PSR flyback converter with high efficiency over a wide input voltage range of 4.5 V to 42 V. The isolated output voltage is sampled from the primary-side flyback voltage which eliminates the need for an optocoupler, voltage reference, or third winding from the transformer for output voltage regulation. The high level of integration results in a simple, reliable, and high-density design with one component crossing the isolation barrier. Boundary conduction mode (BCM) switching enables a compact magnetic solution and better than ±1.5% load and line regulation performance. An integrated 65 V power MOSFET provides output power up to 7 W with enhanced headroom for line transients.

The LM25180 converter simplifies implementation of isolated DC/DC supplies with optional features to optimize performance of the target end-equipment. The output voltage is set by one resistor, while an optional resistor improves output voltage accuracy by negating the thermal coefficient of the flyback diode voltage drop. The device includes an internally-fixed or externally-programmable soft-start, optional bias supply connection for higher efficiency, precision enable input with hysteresis for adjustable line UVLO, hiccup-mode overload protection, and thermal shutdown protection with automatic recovery. The LM25180 flyback converter is available in an 8-pin, 4 mm × 4 mm, thermally-enhanced WSON package with 0.8 mm pin-pitch.