SC1402

• 6V to 30V Input range
• 3.3V and 5V dual synchronous rectified outputs
• Fixed frequency or PSAVE for maximum efficiency over wide load current range
• 5V/50mA linear regulator
• 12V/120mA linear regulator
• Precision 2.5V reference output
• Programmable power-up sequence
• Power good output (RESET)
• Output over current protection
• Output over voltage protection
• Output under voltage shut down
• 4A typical shut down current
• 7mW typical quiescent power

• Notebook and subnotebook computers
• PDAs and Mobile communicators
• Desktop DC-DC converters

The SC1402 is pin compatible with the MAX1632 with improved load regulation performance. The SC1402 is a multiple-output power supply controller designed to power logic supply components in battery operated systems. The SC1402 utilizes synchronous rectified buck topologies to generate two voltages, (3.3V and 5V) with up to 95% efficiency. It also provides two linear regulators for system housekeeping functions. The 12V linear regulator output is generated from a coupled inductor of the 5V switching regulator.

Control functions include: power up sequencing, soft start, power-good signaling, automatic bootstrapping for high side MOSFETs, and frequency synchronization. An internal precision 2.5V reference ensures ±2% output voltage. The internal oscillator can be adjusted to 200kHz, 300kHz or synchronized to an external clock. The MOSFET drivers provide 1A peak drive current for fast MOSFET switching.

The SC1402 includes a PSAVE enable input to select a pulse skipping mode for high efficiency or a fixed frequency mode for low noise operation.