Cost effective and reliable magnetic ballast replacement eliminates electrolytics

August 22, 2013 // By Paul Buckley
International Rectifier has introduced a reliable, efficient and cost effective control IC for magnetic ballasts used in fluorescent lamps.

IRS2538DS emulates the behaviour of a magnetic ballast control system, using IR’s ballast and high-voltage technologies to offer an easy to use, high-performance, cost effective, single-chip magnetic ballast replacement.
In an SO8 package, IRS2538DS uses a novel control method to achieve high power factor with ultra-low THD to eliminate the need for a Power Factor Correction (PFC) stage and electrolytic capacitor at the input. The new IC integrates a 600V half-bridge control circuit, bootstrap MOSFET and comprehensive set of protection features to further reduce component count and PCB area, and increase reliability.
It also features preheat, ignition and running lamp modes, closed-loop lamp current control, fixed pre-heat time (2 sec typical), adaptive deadtime (0.5 µsec to 1.5 µsec typical), lamp insert auto-restart, micropower start-up (125 µA) and an internal 15.6V Zener diode clamp on Vcc. It costs $0.94 (10,000).