Dimmable Single-Stage Digital LED Driver for 15W SSL Retrofit Bulb Applications

The iW3609 is optimized for dimmable SSL retrofit bulbs requiring high power factor (PF), low total harmonic distortion, outstanding TRIAC dimmer capability, and low BOM cost. Designed for 15W applications, the iW3609 uses advanced digital control technology to detect the dimmer type, provide dynamic impedance to interface with the dimmer and control the LED brightness at the same time. A proprietary input current shaping option enables the iW3609 to balance the power loss of the bleeder circuit.

Renesas' patented PrimAccurate™ primary-side control eliminates the need for a secondary-side regulator and opto-isolator. The iW3609 further reduces the BOM cost by using low-cost bipolar junction transistors (BJTs), eliminating high-voltage electrolytic capacitors, and including built-in over-temperature protection (OTP) derating with no NTC resistor. The OTP derating feature enables continuous light output while protecting the LED driver by reducing output current drive to the LEDs during an over-temperature event.