L5981

www.DataSheet4U.com L5981 1A step-down switching regulator Features „ „ „ „ „ „ „ „ „ „ 1A DC output current 2.9V to 18V input voltage Output voltage adjustable from 0.6V 250kHz switching frequency, programmable up to 1MHz Internal soft-start and inhibit Low dropout operation: 100% duty cycle Voltage feed-forward Zero load current operation Over current and thermal protection VQFN3x3-8L package VFQFPN8 3x3 Description The L5981 is step down switching regulator with 1.5A current limited embedded power MOSFET, so it is able to deliver in excess of 1A DC current to the load depending on the application condition. The input voltage can range from 2.9V to 18V, while the output voltage can be set starting from 0.6V to VIN. Having a minimum input voltage of 2.9V, the device is suitable also for 3.3V bus. Requiring a minimum set of external components, the device includes an internal 250kHz switching frequency oscillator that can be externally adjusted up to 1MHz. The QFN package with exposed pad allows reducing the RthJA down to approximately 60°C/W. Applications „ Consumer: STB, DVD, DVD recorder, car audio, LCD TV and monitors Industrial: Chargers, car battery, PLD, PLA, FPGA Networking: XDSL, modems, DC-DC modules Computer: Optical storage, hard disk drive, printers, audio/graphic cards Application circuit „ „ „ Figure 1. L5981 October 2007 Rev 2 1/37 www.st.com 37 www.DataSheet4U.com Contents L5981 Contents 1 Pin settings . . . . . . . . . . . . . . . . . . . . . ...