Description

The SC414/SC424 is a stand-alone synchronous buck regulated power supply. It features integrated power MOSFETs, a bootstrap switch, and a 5V LDO in a space-saving MLPQ-4x4mm 28-pin package. The device is highly efcient and uses minimal PCB area. It uses pseudo-f xed frequency adaptive on-time operation to provide fast transient response.

The SC414/SC424 supports using standard capacitor types such as electrolytic or special polymer, in addition to ceramic, at switching frequencies up to 1MHz. The programmable frequency, synchronous operation, and select able power-save provide high efciency operation over a wide load range.

Additional features include cycle-by-cycle current limit, soft-start, under and over-voltage protection, programmable over-current protection, soft shutdown, and selectable power-save. The device also provides separate enable inputs for the PWM controller and LDO as well as a power good output for the PWM controller.

The input voltage can range from 3V to 28V. The wide input voltage range, programmable frequency, and 5V LDO make the device extremely ?exible and easy to use in a broad range of applications. It can be used for single cell or multi-cell battery systems in addition to traditional DC power supply applications.

The 5V LDO or an external 3.3V to 5V supply can be used to provide the bias voltage for the SC414/SC424. When the SC414/SC424 is used as a 5V output switching regulator, the 5V LDO can be used as an initial bias supply for the device. Once the switch regulator output is in the switch over range, the LDO will be bypassed by the switcher output for optimum efciency.

Features

■ Input voltage — 3V to 28V

■ Internal power MOSFETs — 6A

■ Integrated bootstrap switch

■ Smart power-save protection

■ Integrated 5V, 150mA LDO with bypass capability

■ TC compensated RDS(ON) sensed current limit

■ Pseudo-fxed frequency adaptive on-time control

■ Designed for use with ceramic capacitors

■ Programmable VIN UVLO threshold

■ Independent enable for switcher and LDO

■ Selectable ultrasonic power-save (SC414)

■ Selectable power-save (SC424)

■ Internal soft-start and soft-shutdown at output

■ Internal reference — 1 tolerance

■ Over-voltage and under-voltage fault protection

■ Power good output

■ SmartDriveTM

■ Lead-free 4x4mm, 28 Pin MLPQ package

■ Fully WEEE and RoHS compliant, and halogen free

Applications

■ Notebook, desktop, tablet, and server computers

■ Networking and telecommunication equipment

■ Printers, DSL, and STB applications

■ Embedded applications

■ Power supply modules

■ Point of load power supplies