Phase control loop ballast ICs for transformer-less dimming
( 01 Aug 2004 )
The 600V IR21592 and IR21593 dimming ballast ICs from International Rectifier feature a phase control loop and half-bridge driver for fluorescent lamps. The new devices include a comprehensive set of protection features including dimming ignition detection as well as brown-out and over-temperature protection. A microcontrollable interface is included. The IR21592 is designed for linear lamps while the IR21593 is designed for compact lamps. The phase control loop architecture senses and regulates the phase current of the half-bridge. A single pin with an external current-sensing resistor is used to measure all feedback information necessary for pre-heat, ignition, dimming and lamp fault. The result is a closed loop system that simplifies linear dimming. The control method eliminates a separate current-sensing transformer.
IR21592 and IR21593, $1.50 (50,000).
International Rectifier Fax 852-2540-5835 www.irf.com
The 600V IR21592 and IR21593 dimming ballast ICs from International Rectifier feature a phase control loop and half-bridge driver for fluorescent lamps. The new devices include a comprehensive set of protection features including dimming ignition detection as well as brown-out and over-temperature protection. A microcontrollable interface is included.
