450-V linear controller simplifies offline LED lighting

October 03, 2014 // By Graham Prophet
A high-voltage current controller for downlights and fixtures dims with both microcontroller controllers and standard wall dimmers

Texas Instruments has a 450-V linear controller that simplifies current regulation of high-voltage LED strings. The TPS92410 controller integrates a multiplier and tunable phase dimmer detection, as well as analogue dimming inputs and drive circuit protection functions to ease design of downlights, fixtures and lamps powered from an offline AC or conventional DC power source.

The TPS92410 operates over 9.5-V to 450-V input voltage range and functions as a standalone high-voltage LED string current regulator or pairs with TI's TPS92411 floating switch to provide power in mains AC linear direct drive applications. Together, the TPS92410 and TPS92411 feature driver and LED circuit protection while providing an inductor-free, low LED current ripple lighting solution. The TPS92410 includes an analogue dimming input pin with LED shutoff to provide easy light intensity control in intelligent, MCU-based light fixtures using the ultra-low-power MSP430F5172 microcontroller or SimpleLink ZigBee CC2530 wireless MCU.

The TPS92410 can be used with AC and DC applications; it has under-voltage lockout, MOSFET over-voltage protection and thermal foldback prevent driver and LED damage during fault conditions. In AC applications with the TPS92411, it is compatible with legacy TRIAC and reverse phase dimmers in AC mains powered LED lighting applications. An on-chip, internal multiplier produces very high power factor correction at greater than 0.95 with within ±3% regulation.

TPS92410, in a 13-pin SOIC package, costs $0.65 (1,000); the 120-V TPS92410EVM-001 and 230-V TPS92410EVM-002 light engine evaluation modules are available at $99.00 each. A downloadable 120V or 230V TPS92410 design calculator tool helps with selecting external components, and you can predict LED current ripple with the TPS92410 PSpice transient model.

TI; www.ti.com/tps92410-pr-eu