Description

The SC461 is a synchronous EcoSpeed® buck regulator which incorporates Semtech’s advanced, patented adaptive on-time control architecture to provide excellent light-load efficiency and fast transient response. It features an integrated bootstrap switch and a fixed 5V LDO in a 3 x 3(mm) package. The device is highly efficient and uses minimal PCB area.

The SC461 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 programmable power-save provide high efficiency operation over a wide load range.

Features

■ Power system

   • Input voltage — 3V to 28V

   • Integrated bootstrap switch

   • Fixed 5V LDO output — 200mA

   • 1% reference tolerance -40 to +85 °C

   • Selectable internal/external bias power supply

   • EcoSpeed® architecture with pseudo-fixed frequency adaptive on-time control

■ Logic input and output control

   • Independent enable controls for LDO and switcher

   • Programmable soft-start time

   • Programmable VIN UVLO threshold

   • Power Good output

   • Selectable power-save mode

■ Protections

   • Automatic restart on fault shutdown

   • Over-voltage and under-voltage

   • TC compensated RDS(ON) sensed current limit

   • Thermal shutdown

   • Smart power-save

   • Pre-bias start-up

■ Capacitor types: SP, POSCAP, OSCON, and ceramic

■ Package — 3 x 3(mm), 20-pin MLPQ

■ Lead-free and halogen-free

■ RoHS and WEEE compliant

Applications

■ Office automation and computing

■ Networking and telecommunication equipment

■ Point-of-load power supplies and module replacement  