Description
The SC1404 is a multiple-output power supply controller designed for battery operated systems. The SC1404 provides synchronous rectified buck converter control for two power supplies. An efficiency of 95% can be achieved. The SC1404 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. The SC1404 also provides two linear regulators for system housekeeping. The 5V linear regulator takes its input from the battery; for efficiency, the output is switched to the 5V output when available. The 12V linear regulator output is generated from a coupled inductor off the 5V switching regulator.

Features
◆ 6 to 30V input range (operation possible below 6V)
◆ 3.3V and 5V dual synchronous outputs
◆ Fixed-frequency or PSAVE for maximum efficiency over wide load current range
◆ 5V/50mA linear regulator
◆ 12V/200mA linear regulator
◆ Virtual Current Sense TM for enhanced stability
◆ Accurate low-loss current limiting
◆ Out-of-phase switching reduces input capacitance
◆ External compensation supports wide range of output filter components for reduced cost
◆ Programmable power-up sequence
◆ Power Good output
◆ Output overvoltage & overcurrent protection with output undervoltage shutdown
◆ 4µA typical shutdown current
◆ 6mW typical quiescent power

Applications
◆ Notebook and Subnotebook Computers
◆ Automotive Electronics
◆ Desktop DC-DC Converters