The SC1403 is a multiple-output power supply controller designed to power battery operated systems. The SC1403 provides synchronous buck converter control for two (3.3V and 5V) power supplies. An efficiency of 95% can be achieved for the two supplies. The SC1403 uses Semtech's proprietary Virtual Current SenseTM technology along with external error amplifier compensation to achieve enhanced stability and DC accuracy over a wide range of output filter components while maintaining fixed frequency operation. Lossless current sensing can be used to eliminate current sense resistors and reduce cost. The SC1403 also provides a 5V linear regulator for system housekeeping. The 5V linear regulator is derived from the battery; for improved efficiency, the output is switched to the 5V output when available. Control functions include power-up sequencing, soft start, power-good signaling, and frequency synchronization. Line and load regulation is to +/-1%. The internal oscillator can be set to 200kHz, 300kHz, or synchronized to an external clock. The mosfet drivers provide >1A peak drive current for fast mosfet switching.