Supertex has introduced the HV9801A, a switch dimmable LED driver IC designed to drive LEDs in dimmable household and office lighting applications. The IC dims LED lamp brightness to one of four preset levels through simple, rapid toggling of a light switch. Light levels progress up and down sequentially and if the switch is turned off for more than a second, the lamp returns to full brightness.
Switch dimming offers an attractive alternative to TRIAC dimming as it enables dimming of lamps in any location, provides a better quality light source without flicker, and increases energy efficiency through the reduction of the excess circuitry required to accommodate the holding current of the TRIAC dimmer. The HV9801A works with all existing light switches and does not require installation of a wall dimmer.
As opposed to many LED driver ICs that utilise peak current control to regulate output current, the device employs a patented average-mode current control method that requires no loop compensation or high-side sensing. This proprietary control method provides quick and accurate response to input voltage fluctuations and delivers high accuracy (over 97%) and line and load regulation of the LED current.