SC1401

• >90% Efficiency (SMPS)
• 6.0V to 30V Input range
• 1.25V to 5.5V Adjustable output (SMPS)
• PWM and LDO regulator outputs
• High output gate drive of 2 Amps (SMPS)
• Power save mode for light load operation
• 200kHz/300kHz fixed-frequency PWM operation
• 2mA Typical quiescent current
• 2µA Typical shutdown current

• Notebook and palmtop computers
• LCD monitors
• Internet appliances

The SC1401 is a synchronous buck regulator designed to power the latest generation microprocessors in battery operated systems. The SC1401 may be used to provide both the I/O and core voltages utilizing synchronous rectification for the core supply voltage and an LDO N-Channel MOSFET controller for the I/O supply voltage. A 1.25 volt reference allows lower output voltages required by today's portable microprocessors.

The synchronous buck regulator is capable of achieving efficiencies up to 95%. The gate drive circuitry can deliver 2.0A peak currents, allowing the use of N-channel MOSFETs for lower switching and conduction losses.

A digital soft start is provided to ensure orderly start up of the power supply without the need for external components. At light load in power save mode, the controller changes mode of operation by missing gate drive cycles, thus reducing gate drive current and improving efficiency. A logic high on PSAVE disables the power saving mode thus reducing noise. The SC1401 is fabricated in a high performance BiCMOS process. This process reduces the power dissipation in low current and shutdown operation modes and improves efficiency.

The LDO controller is a high performance positive voltage regulator designed to provide a low noise power source to the microprocessor peripherals by driving a low cost external N-Channel MOSFET.