One-Chip Electronic Ballast for Fluorescent Lamps

The L6585 one-chip solution, in fact, is the first on the market to enable EOL (End-of-Life) detection in either “lamp-to-ground” or “block capacitor-to-ground” ballast configurations. For the first time, manufacturers can choose how to design their application to simplify board qualification and easily pass ballast security tests.

Unlike previous solutions that require a Combo IC and several external components to feature EOL detection and the specific protections required by the new types of fluorescent lamps, the L6585 ensures all these necessary functions, thus eliminating the need for external circuits, drastically reducing design time and complexity, dramatically lowering costs, and increasing reliability.

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 Combo 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 over-voltage 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 an extremely low Total Harmonic Distortion (THD).

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 $1.4 in 10,000 unit quantities. Samples of the Combo IC are available now and volume production is scheduled for January 2007.