7.1 Overview

The LMR24220 step-down switching regulator features all required functions to implement a cost effective, efficient buck power converter capable of supplying 2 A to a load. It contains dual N-channel main and synchronous MOSFETs. The constant on-time (COT) regulation scheme requires no loop compensation, results in fast load transient response and simple circuit implementation. The regulator can function properly even with an all ceramic output capacitor network and does not rely on the ESR of the output capacitor for stability. The operating frequency remains constant with line variations due to the inverse relationship between the input voltage and the on-time. The valley current limit detection circuit, with the limit set internally at 2.8 A, inhibits the main MOSFET until the inductor current level subsides.

The LMR24220 can be applied in numerous applications and can operate efficiently for inputs as high as 42 V. Protection features include output over-voltage protection, thermal shutdown, V_CC undervoltage lockout, and gate-drive undervoltage lockout. The LMR24220 is available in a small DSBGA chip-scale package.