7.1 Overview

The LM5160-Q1 step-down synchronous switching regulator features all the functions needed to implement a low-cost, efficient buck converter capable of supplying 2 A to the load. This high voltage regulator contains 65-V N-channel buck and synchronous rectifier switches and is available in a 14-pin HTSSOP package with 0.65-mm pin pitch. The regulator operation is based on an adaptive constant on-time control architecture where the on-time is inversely proportional to input voltage V_IN. This feature maintains a relatively constant operating frequency with load and input voltage variations. A constant on-time switching regulator requires no loop compensation resulting in fast load transient response. Peak current limit detection circuit is implemented with a forced off-time during current limiting which is inversely proportional to voltage at the feedback pin, V_FB and directly proportional to V_IN. Varying the current limit off-time with V_FB and V_IN ensures short-circuit protection with minimal current limit foldback. The LM5160-Q1 can be applied in numerous end equipment systems requiring efficient step-down regulation from higher input voltages. This regulator is well-suited for 24-V industrial systems as well as 48-V telecom and PoE voltage ranges. The LM5160-Q1 integrates an undervoltage lockout (EN/UVLO) circuit to prevent faulty operation of the device at low input voltages and features intelligent current limit and thermal shutdown to protect the device during overload or short circuit.