Description

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 Sense™ 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.

Features

◆ 3.3V and 5V dual synchronous outputs, resistor programmable to 2.5V

◆ Fixed frequency or PSAVE operation for maximum efficiency over wide load range

◆ 5V / 50mA linear regulator

◆ Virtual Current Sense™ for enhanced stability

◆ Lossless current limiting

◆ Out of phase switching reduces input capacitance

◆ External compensation supports wide range of output filter components

◆ Programmable power-up sequence

◆ Power Good output

◆ Output overvoltage and overcurrent protection with output undervoltage shutdown

◆ 6µA typical shutdown current

◆ 6mW typical quiescent power

Applications

◆ Notebook and subnotebook computers

◆ Tablet PCs

◆ Embedded applications