SC414/SC424 6A Integrated FET Regulator with 5V LDO POWER MANAGEMENT Features Description Input voltage 3V to 28V The SC414/SC424 is a stand-alone synchronous buck regu- Internal power MOSFETs 6A lated power supply. It features integrated power MOSFETs, Integrated bootstrap switch a bootstrap switch, and a 5V LDO in a space-saving MLPQ- Smart power-save protection 4x4mm 28-pin package. The device is highly effi cient and Integrated 5V, 150mA LDO with bypass capability uses minimal PCB area. It uses pseudo-fi xed frequency TC compensated R sensed current limit adaptive on-time operation to provide fast transient DS(ON) Pseudo-fi xed frequency adaptive on-time control response. Designed for use with ceramic capacitors The SC414/SC424 supports using standard capacitor types Programmable V UVLO threshold IN such as electrolytic or special polymer, in addition to Independent enable for switcher and LDO ceramic, at switching frequencies up to 1MHz. The pro- Selectable ultrasonic power-save (SC414) grammable frequency, synchronous operation, and select- Selectable power-save (SC424) able power-save provide high effi ciency operation over a Internal soft-start and soft-shutdown at output wide load range. Internal reference 1% tolerance Over-voltage and under-voltage fault protection Additional features include cycle-by-cycle current limit, Power good output TM soft-start, under and over-voltage protection, program- SmartDrive mable over-current protection, soft shutdown, and select- Lead-free 4x4mm, 28 Pin MLPQ package able power-save. The device also provides separate enable Fully WEEE and RoHS compliant, and halogen free inputs for the PWM controller and LDO as well as a power Applications good output for the PWM controller. Notebook, desktop, tablet, and server computers The input voltage can range from 3V to 28V. The wide Networking and telecommunication equipment input voltage range, programmable frequency, and 5V Printers, DSL, and STB applications LDO make the device extremely fl exible and easy to use in Embedded applications a broad range of applications. It can be used for single cell Power supply modules or multi-cell battery systems in addition to traditional DC Point of load power supplies 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 regula- tor, 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 effi ciency. 2009 Semtech Corporation September 11, 2009 1SC414/SC424 Typical Application Circuit ENABLE LDO ENABLE PSAVE V5V RTON RPGOOD 154K RILIM 10K 9.09K PGOOD 28 27 26 25 24 23 22 PAD 2 PAD 1 VIN AGND FB V5V 1 21 FB LX 2 20 V5V LX 3 19 C1 AGND PGND C2 VOUT 1F 4 18 1F SC414/SC424 VOUT PGND 5 17 VIN PGND 6 16 VLDO PGND 7 15 BST LX C3 100nF PAD 3 LX CBST 8 9 10 11 12 13 14 1F VIN +12V CIN CIN 10F 10 F RGND 0 VOUT L1 1.5H VOUT 1V 6A, 250kHz + COUT RFB1 C4 220F 10nF 10K FB RFB2 30K Key Components Component Value Manufacturer Part Number Web CIN 10F/25V Murata GRM32DR71E106KA12L www.murata.com COUT 220 F/15m/6.3V Panasonic EEFUE0J221R www.panasonic.com www.vishay.com L1 1.5H/9A Vishay IHLP2525CZER1R5M01 All other small signal components (resistors and capacitors) are standard SMT devices. 2 VIN ENL VIN TON VIN AGND VIN EN/PSV LXBST LXS PGND ILIM PGND PGOOD