Multi-topology PWM controller for isolated supplies
The UCC3809P-2 is a current-mode PWM controller from Texas Instruments designed for offline and DC-DC converter applications. It supports boost, buck, flyback, and forward topologies, making it a flexible choice for a range of isolated power supply designs. Operating from an 8 V to 19 V supply (Vcc/Vdd), the controller drives an external power switch — it has no internal switch, so the designer selects the MOSFET or IGBT that matches the output power target. Switching frequency reaches 1 MHz, which allows the use of smaller magnetics and capacitors compared to lower-frequency controllers. The 70% maximum duty cycle suits forward and flyback converters operating in continuous conduction mode.
Temperature grade and package fit
This makes it suitable for avionics, downhole instrumentation, and other high-reliability environments where the ambient temperature exceeds the commercial or industrial envelope. The controller is offered in an 8-VSSOP package (also listed as 8-TSSOP / 8-MSOP, 0.118-inch width). The small footprint suits space-constrained board layouts, but the fine-pitch leads require careful solder-paste stencil design for consistent wetting. Control features include frequency control and soft start, giving the designer a way to set the switching frequency with an external resistor and to limit inrush current during startup.
No stock-holding claim is made; each RFQ is quoted to order.