DESCRIPTION

The SC1578 is a high performance step-down DC-DC converter, designed to drive an external P-channel MOSFET to generate programmable output voltages. Two main schemes of pulse-skipping and pulsefrequency modulation are employed to maintain low quiescent current and high conversion efficiency over wide ranges of input voltage and loads. The SC1578 delivers 10mA to 2A of output current with 87-93 efficiency at VIN=9V, VOUT=5V. A current sense comparator with both inverting and non-inverting inputs uncommitted is included to provide the crucial function of either current limit protection or constant output current control.

FEATURES

• 4V to 24V input voltage operation.

• High efficiency (up to 95).

• Low quiescent current at 90µA.

• Pulse-skipping and pulse-frequency modulation.

• Inputs-uncommitted current sense comparator.

• Duty cycle adjustable

• 90kHz to 280kHz oscillator frequency

• Power-saving shutdown mode (8µA Typical).

• Push-pull driver output

APPLICATIONS

• Notebook 5V/3.3V main power

• Step-down DC-DC converter module.

• Constant current source for battery chargers.