STMicroelectronics — L6981/L6982 Synchronous Step-Down Regulator IC

The L6981 and L6982 from STMicroelectronics are easy-to-use, synchronous step-down regulator ICs which feature a wide input-voltage range of 3.5 V to 38 V, making them ideal for use in 24 V industrial power buses. The L6981 can supply up to 1.5 A dc to the load, and the L6982 can supply 2 A.

The L6981 and L6982 are based on a peak current-mode architecture. Housed in an SO8 package with internal compensation, these devices minimize the complexity and size of power-system designs.

The regulators are available in versions operating in a low-consumption mode (LCM) or a low-noise mode (LNM). The LCM maximizes efficiency at light loads with controlled output-voltage ripple: this variant is suitable for battery-powered applications.

LNM keeps the switching frequency constant and minimizes output-voltage ripple in light-load operations. This is ideal for noise-sensitive applications.

Typical shut-down current is 2 µA when the device is disabled. As soon as the Enable pin is pulled up, the device is enabled and the internal 1.3 ms soft-start begins. Pulse-by-pulse current sensing on both power elements provides effective constant current protection. Thermal shut-down protection prevents thermal run-away.

The L6981 and L6982 are included in the ST 10-year longevity program which ensures long-term component supply.