SDAA356 July 2026 LM5125A-Q1 , LM5126A-Q1
The LM5125A-Q1 is a stackable, dual-phase synchronous boost converter specifically designed for automotive audio amplifier applications. The output voltage is adjustable through the ATRK/DTRK pin.
To meet the increasing power demands of modern audio amplifiers, designs employing 3-phase and 4-phase operation are gaining popularity. A four-phase configuration can be readily achieved by connecting two LM5125A-Q1 devices. In this setup, the primary controller regulates the output voltage and communicates a current command (COMP) to the secondary controller. The secondary controller follows the current command and synchronizes with the primary controller with a phase shift.
This document provides a comprehensive guide to configuring and implementing 3-phase and 4-phase systems using the LM5125A-Q1, outlining the specific functionalities when the device is configured as either the primary or secondary controller.