The L7981 is a step-down switching regulator with a DC output current of 3A, an input voltage range of 4.5V to 28V, an adjustable output voltage starting from 0.6V, a switching frequency of 250kHz (programmable up to 1MHz), internal soft-start and enable functions, low dropout operation, voltage feed-forward, zero load current operation, overcurrent and thermal protection, etc. It is suitable for consumer electronics, industrial equipment, networking devices, and computer applications, and is suitable for LED driving.