SC1403 Datasheet | SEMTECH

Description The SC1403 is a multiple-output power supply controller designed to power battery operated systems. The SC1403 provides synchronous rectified buck converter control for two (3.3 V and 5 V) power supplies. An efficiency of 95% can be achieved for the two supplies. The SC1403 uses Semtech’s proprietary Virtual Current Sense TM technology along with external error amplifier pensation to achieve enhanced stability and DC accuracy over a wide range of output filter ponents while maintaining fixed frequency operation. The SC1403 also provides a linear regulator for system housekeeping. The 5 V linear regulator takes its input from the battery; for 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% of the output voltage. The internal oscillator can be adjusted to 200 k Hz or 300 k Hz or synchronized to an external clock. The MOSFET drivers provide >1A peak drive current for fast MOSFET switching. skipping mode for high efficiency at light load, or fixed frequency mode for low noise operation. PRELIMINARY Features ‹ 3.3V and 5V dual synchronous outputs, resistor ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ programmable to 2.5V Fixed frequency or PSAVE for maximum efficiency over wide load current range 5V / 50m A linear regulator TM Virtual Current Sense for enhanced stability Accurate low loss current limiting Out of phase switching reduces input capacitance requirements External pensation supports wide range of output filter ponents Programmable power-up sequence Power good output Output overvoltage & overcurrent protection with output undervoltage shutdown 4µA typical shutdown current 6m W typical quiescent power Applications ‹ Notebook and subnotebook puters ‹ Automotive electronics The SC1403 includes a PSAVE# input to select pulse ‹ Desktop DC-DC converters Typical Application Circuit SHDN# V+ SYNC...