Dual mode off-line controller for non-dimmable LED lighting

March 20, 2012 // By Paul Buckley
Texas Instruments Incorporated has introduced a new off-line primary side sensing controller to the company's portfolio of non-dimming LED drivers. The new TPS92310 AC/DC constant current driver with power factor correction (PFC) reduces cost and shrinks-to-fit in high-power LED retrofit bulbs, including A19, PAR30/38 and GU10.

The TPS92310 is the first in a family of primary side, regulated controllers with PFC.  In May, TI will offer the TPS92311 with similar features and an integrated, 600V power FET with avalanche energy capability, further reducing solution size and component count. The TPS92310 and TPS92311 join TI’s portfolio of off-line LED lighting controllers that include the National LM3445, the industry’s first TRIAC dimmable LED driver with both full-range and flicker-free dimming.

The TPS92310 LED driver’s AC input voltage supports all common line voltages (100 V, 120 V, 230 V, 240 V, 277 V), including US commercial.

The device’s true primary side sensing and regulation provides accurate LED current regulation, eliminating optocoupler, secondary error amplifier and associated passive components. B ill of materials is reduced by 14 percent or more compared to today’s solutions.

The device can select from dual operating modes.  Adaptive constant on-time (COT) provides inherent power factor correction with no external components. PFC reduces the EMI signature to ensure regulatory approval.  Peak current control provides low LED current ripple to minimize stroboscopic effects.  Critical-Conduction-Mode (CCM) with Zero-Current Detection (ZCD) provides valley switching for improved power conversion efficiency and low-EMI.  Cycle-by-cycle current limit, over/under voltage protection and thermal shutdown also protects the LED driver and user against fault and abnormal operating conditions.