The ST1S40 device is an internally compensated 850 kHz fixed-frequency PWM synchronous step-down regulator. The ST1S40 operates from 4.0 V to 18 V input, while it regulates an output voltage as low as 0.8 V and up to VIN. The ST1S40 integrates a 95 mΩ high side switch and 69 mΩ synchronous rectifier allowing very high efficiency with very low output voltages. The peak current mode control with internal compensation delivers a very compact solution with a minimum component count. The ST1S40 is available in HSOP-8, VFQFPN 4 mm x 4 mm - 8 lead, and standard SO8 package.

3 A DC output current
4.0 V to 18 V input voltage
Output voltage adjustable from 0.8 V
850 kHz switching frequency
Internal soft-start
Integrated 95 mΩ and 69 mΩ Power MOSFETs
All ceramic capacitor
Enable
Cycle-by-cycle current limiting
Current fold back short-circuit protection
Available in HSOP-8, VFQFPN4x4-8L, and SO8 packages
Applications
μP/ASIC/DSP/FPGA core and I/O supplies
Point of load for: STB, TVs, DVD
Optical storage, hard disk drive, printers, audio/graphic cards