L6981-2-3: Synchronous step-down converters with low quiescent current

The L6981, L6982 and L6983 are easy-to-use synchronous monolithic step-down regulators capable of delivering from 1.5 to 3 A DC to the load. The wide input voltage range makes these devices suitable for a broad range of applications.

They are all available both in low-consumption mode (LCM) and low-noise mode (LNM) versions:

  • LCM maximizes the efficiency at light load with controlled output voltage ripple so the device is suitable for battery-powered applications
  • LNM makes the switching frequency constant and minimizes the output voltage ripple for light-load operations, meeting specifications for noise-sensitive applications

These buck regulators embed a full set of protection functions (overcurrent, overvoltage, and over-temperature) to increase the mean time between failures (MTBF) and reduce the number of external components required, thus lowering BOM costs.

 The 6V to 75V synchronous buck controller : L3751 

Untangle your industrial power conversion design and take advantage of high efficiency at all loads.

Choose your product:

Key features & applications:

  • 3.5 V to 38 V operating input voltage
  • Output voltage from 0.85 V to VIN
  • From 1.5 A DC to 3 A DC output current
  • From 17 to 20 μA operating quiescent current


  • 2 μA shutdown current
  • Output voltage sequencing
  • Synchronization to external clock for LNM devices
  • 3.3 V and 5 V fixed output voltage versions

Application examples

industrial power

24 V buses industrial power systems

battery-powered 24 V battery powered equipment
node Decentralized intelligent nodes
Sensors and always-on applications
low noise
Low-noise applications

Recommended resources


Switching Converters (DC-DC) Quick reference guide

This guide provides developers with an overview of our most commonly used switching regulators and will help identify the most appropriate solution for each type of application.

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Join this on-demand webinar as we explain the different Vbus topologies and associated product portfolios. We will showcase the benefits of our DC-DC and LDO regulators, eFuses, and LED drivers, along with the evaluation boards and free simulation tools available to help designers go to market faster.

We will help you:

  • Understand the advantages of ST power management products in your designs
  • Learn how to effectively identify and select the best regulators for your applications
  • Learn more about our simulation and design aid tool environment

Evaluation boards:

You may be interested in:



60 V 300 mA synchronous step-down switching regulator with 10 µA quiescent current.

More information here