AIC1579

AIC1579/L Step-Down Switching Regulator Controller FEATURES Operation Voltage up to 15V. Simple Voltage-Mode PWM Control. Fast Transient Response. 2V and 1.3V ± 2% Feedback Voltage Reference Option. Adjustable Current Limit without External Sense Resistors. 200KHz Free-Running Oscillator. Short-Circuit Protection with Low Short Circuit Output Current. DESCRIPTION The AIC1579 is a high-power, high-efficiency voltage-mode switching regulator controller for motherboard VI/O power supply applications. Designed to drive an N-channel MOSFET in a standard buck topology, the AIC1579 features a high voltage CMOS output driver, short-circuit protection, and 8-pin package. An external 4-bit Digital-to-Analog Converter (DAC) can be used along with the AIC1579 to adjust the output voltage from 2.0V to 3.5V in 0.1V increments. Table 1 on the following page specifies the corresponding output voltage for 16 combinations of DAC inputs as in the typical application circuit. The 200KHz switching frequency allows for using small external components while maintaining high conversion efficiency. The 11MHz bandwidth and 6V/µS slew rate of the error amplifier ensures high converter bandwidth and fast transient response. The AIC1579 provides adjustable overcurrent and short-circuit protections by sensing the output current across the on resistance of the external N-channel MOSFET rather than an external low value sense resistor. The AIC1579L provides lower reference voltage (1.30V) than the default...