SC473

Single-Phase Single Chip Graphics Core Power Supply POWER MANAGEMENT Description The SC473 is a single-phase chip, high-performance PWM controller designed to power advanced graphic cores. Onchip support is provided that includes slew-rate controlled VID transitions. The SC473 implements hysteretic control technology which provides the fastest possible transient response while avoiding the stability issues inherent to classical PWM www.DataSheet4U.com controllers. Eliminating the sense resistors reduces costs and PCB area, plus increases system efficiency. Integrated SmartDriver™ technology initially turns on the high-side driver with ‘soft’ drive to reduce ringing, EMI, and capacitive turn-on of the low side MOSFET, while also increasing overall efficiency. Hysteretic operation adaptively reduces the SC473 switching frequency at light loads. Combined with an automatic “powersave” mode which prevents negative current flow in the low-side FET, system efficiency is significantly enhanced during light loading conditions. A 5-bit DAC, accurate to 0.85%, sets the output voltage reference, and implements the voltage range required by the processor. The DAC slew rate is externally programmed to minimize transient currents and audible noise. True differential remote sensing provides accurate point-of-load regulation at the processor die. Other features include programmable soft-start, an open-drain PWRGD output, dual-level over-voltage and programmable over-current protection. The SC473 i...