International Rectifier Corp. (El Segundo, CA) has introduced the IRS2580DS Combo8, an IC that integrates power factor correction (PFC) and ballast control in an 8-pin SO-8 package. To provide power factor correction, the IRS2580DS includes a boost converter control circuit operating in critical-conduction free-running frequency mode. The new IC also includes a 600V half-bridge control circuit working at 50 percent duty-cycle. It has variable frequency for driving the resonant mode lamp output circuit.
Fault protection circuitry protects against mains interrupt, brownout, lamp non-strike, lamp filament failure, and end-of-life. The IRS2580DS requires only two primary control pins to perform ballast functions: an analog voltage-to-frequency input pin for programming the different operating frequencies for preheating, igniting, and running the lamp; and a PWM output pin for controlling the on and off times during each switching cycle of the PFC boost converter.