Current-mode PWM controller for push-pull and half-bridge stages
The Texas Instruments UC3846N is a current-mode PWM controller for step-up and step-up/step-down topologies including boost, flyback, forward converter, half-bridge, and push-pull. It drives two transistor outputs with a maximum duty cycle of 50%. The switching frequency reaches 500 kHz. Control features include current limiting, enable, frequency control, and soft start — all accessible through the 16-pin DIP package.
The controller operates from a 6.95 V to 40 V supply rail.
Through-hole package and assembly fit
The 16-DIP (0.300" width, 7.62 mm pitch) through-hole package is a legacy footprint that still sees use in prototyping, low-volume production, and repair boards where hand-soldering or socketing is preferred.
50% duty cycle — what it means for topology choice
The 50% maximum duty cycle is a hard limit set by the internal logic. In push-pull and half-bridge converters, this ensures equal volt-second balance across the transformer primary and prevents core saturation. For a boost or flyback operating at high input-to-output ratio, 50% duty may be insufficient — those designs typically need a controller with a higher duty ceiling. Check your conversion ratio before committing this part to a boost-only design.
Pricing and availability are confirmed at quote time through our independent distribution network — submit an RFQ for the exact quantity and lead time.