Integrated Switchers Shrink And Reduce Component Count

The IRIS Series integrated switchers are said to simplify design and reduce pc board area and component count by 25% at the same or better efficiency than discrete-based circuits in switched mode power supplies. The devices combine a low-loss, fully characterized avalanche energy HEXFET power MOSFET with a dual-mode voltage and current control IC and are optimized for flyback topologies in universal- and single-input, 60W to 180W swirchers.Six devices in the series provide on-resistances from 0.9½ to 3.95½ and maximum switching currents from 2.5A to 8A. They can operate in either a quasi-resonant or pulse ratio control (PRC) mode. In quasi-resonant mode, switching is done when the drain voltage is at the lowest point of oscillation to reduce switching lossesÑPRC mode is preferred when a low-current standby mode may be required. In 5-pin TO-220 and TO-262 packages, prices start at $1.14 each/1,000. International rectifier CORP., El Segundo, CA. (310) 252-7105.