What this part is and where it fits
The Texas Instruments UCC28703DBVT is an offline flyback controller designed for isolated AC-DC power supplies. It operates from a Vcc range of 9 V to 35 V with a startup threshold of 21 V, and switches between 1 kHz and 130 kHz. The controller drives an external MOSFET — there is no internal power switch. Typical applications include chargers, adapters, and auxiliary housekeeping supplies where isolation is required.
Key ratings and what they mean for the BOM
The 21 V startup voltage sets the bias winding and bulk capacitor design. The 1 kHz to 130 kHz switching range supports valley-switching or quasi-resonant operation, which helps manage EMI and light-load efficiency. Because the controller has no internal switch, the designer must select an external MOSFET and budget for its gate drive — this is the dominant BOM cost alongside the transformer. Fault protection includes current limiting and overvoltage shutdown, which simplifies the secondary-side feedback loop and reduces external component count. The -20°C to 125°C junction temperature range covers industrial and outdoor telecom environments.
Sourcing and lifecycle
There is no end-of-life notice, and the part is available through independent distribution. For current pricing and availability, submit an RFQ — lead times and stock levels are confirmed at quote time.