Fluorescent Ballast IC Saves Energy

Oct 25, 2006 12:14 PM

STMicroelectronics L6585 integrates a power factor corrector (PFC) with a half-bridge controller and all the relevant drivers and logic for an electronic fluorescent lamp ballast. Combining these functions on a single IC allows more light from less energy, while ensuring full compliance with safety and power consumption regulations.

The device enables end-of-life detection in either “lamp-to-ground” or “block capacitor-to-ground” ballast configurations. The L6585 ensures all these necessary functions, thus eliminating the need for external circuits.

The L6585 IC offers independently programmable pre-heating and ignition duration as well as the half-bridge frequencies for each operating phase. As a result, this one IC can serve many different lamp types.

The IC enables high levels of protection on both the PFC and Half-Bridge sections of the device. In addition to the capability of limiting the voltage applied to the lamp and controlling current levels during the ignition and run-mode phase, the L6585 increases ballast reliability by avoiding the capacitive mode in the half-bridge section through the over-current protection.

Other major benefits of the L6585 are the detection of overvoltage and feedback disconnection on the PFC, which stops the IC to avoid ballast damage, and the highly linear multiplier that allows wide-range-mains operation with extremely low total harmonic distortion. Lamp management is also simplified by the automatic re-lamp feature, which allows operators to replace lamps without needing to power off all the other lamps.

Offered in the SO20 ECOPACK package, the L6585 costs $1.40 in 10000-unit quantities. Samples of the Combo IC are available now and volume production is scheduled for January 2007.