Package Melds Control IC And FET For 30W Switchers

Combining a control IC and a low-loss, rugged HEXFET power MOSFET in a single, five-pin package, the IRIS4009 Integrated Switcher is designed for use in ac/dc open-frame power supplies rated up to 30W. Use of application-specific silicon and special packaging reportedly enables the IRIS4009 to handle 60% more power than similar devices classified at the same power level. The device has an avalanche energy rating of 100 mJ and is especially effective in space-constrained flyback converters of up to 30W, such as are commonly found in universal and single input ac/dc power supplies for consumer electronics and adapters. The IRIS4009 can be used as a housekeeping supply in larger ac/dc power supplies or motor drives in up to 30W open-frame or 15W closed-frame configurations. Power supplies made with IRIS4009 have a standby power of less than 1W. Performance is optimized by changing between a pulse ratio control mode at low load conditions and a quasi-resonant mode at high load. The devices also pack several protective features and in a TO-220 package cost $1.68 each/10K and in a TO-262 package, $1.64. INTERNATIONAL RECTIFIER, El Segundo, CA. (310) 252-7105.