Offline LED controller with Triac phase-cut dimming
The TPS92001D is an AC DC Offline Switcher from Texas Instruments, purpose-built for LED lighting applications that require Triac dimming compatibility. It supports both Flyback and Step-Down (Buck) topologies, switching at 100 kHz, and delivers a regulated 5 V output from a single channel.
Triac dimming and topology flexibility
Triac dimming means this controller is designed to work with standard residential phase-cut dimmers — the controller senses the dimmer's conduction angle and adjusts the LED current accordingly, avoiding flicker that plagues many retrofit drivers. The dual-topology support (Flyback or Buck) gives the board designer a choice: isolated designs (Flyback) for safety in metal-enclosure luminaires, or non-isolated Buck for cost-sensitive bulb replacements. Switching at 100 kHz keeps the magnetic components small — a typical flyback transformer for a 10 W LED bulb fits in a 12 mm EP core — while staying below the 150 kHz AM radio band, simplifying EMI filter design.
Package, temperature grade, and supply range
No exposed thermal pad; the junction-to-ambient thermal resistance is managed by the copper pour area on the PCB. The supply voltage range extends to 21 V maximum, which covers the typical rectified DC bus from a 120 VAC or 230 VAC offline front-end after bulk capacitance (roughly 15-20 V for a 12 V LED string).