Description: The IR2159/IR21591 are complete dimming ballast controllers and 600V
half-bridge drivers all in one IC. The architecture includes phase control for transformer-
less lamp power sensing and regulation which minimizes changes needed to
adapt non-dimming ballasts for dimming. Externally programmable features such as
preheat time and current, ignition-to-dim time, and a complete dimming interface with
minimum and maximum settings provide a high degree of flexibility for the ballast
design engineer. Protection from failure of a lamp to strike, filament failures, thermal
overload, or lamp failure during normal operation, as well as an automatic restart
function, have been included in the design. The heart of this control IC is a voltagecontrolled
oscillator with externally programmable minimum frequency. The IR2159/
IR21591 are available in both 16 pin DIP and 16 pin narrow body SOIC packages.