Deadtime Controller Manages Halogen Transformers

Described as the first intelligent control IC designed for transformers that drive low-voltage halogen lamps, the IR2161 adaptive deadtime controller integrates all necessary functions into a single 8-pin DIP or SOIC package. The device employs adaptive control techniques to respond to variations in supply voltage, frequency conditions, and lamp conditions. Its active deadtime circuit detects the point the dc bus voltage in the half bridge slews to 0V and sets the low-side driver high. An internal sample-and-hold system allows approximately the same delay to be used to set the high-side driver high after LO has gone low. Adaptive deadtime control reacts on a cycle-by-cycle basis of the oscillator and adjusts dead time as necessary to maintain soft switching. Other features include a 600V half-bridge driver, overload and short-circuit protection, an output drive of 250 mA or 400 mA, 15.6V Zener diode clamp on VCC, startup power of less than 300 mA, and a 30 to 125 kHz oscillator. Pricing begins at $0.73 each/100,000. For more details, call Wayne Yoshida at at INTERNATIONAL RECTIFIER CORP., El Segundo, CA. (310) 252-7726.