SNVS783K January 2012 – August 2021 LM5017
The LM5017 step-down synchronous switching converter features all the functions needed to implement a low-cost, efficient buck regulator capable of supplying 600 mA to the load. This high-voltage regulator contains 100-V N-channel buck and synchronous rectifier switches and is available in 8-pin thermally-enhanced WSON and SO packages with pin pitches of 0.8 mm and 1.27 mm, respectively. The regulator operation is based on an adaptive constant on-time control architecture where the on-time is inversely proportional to input voltage VIN. 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.
The LM5017 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 communications and PoE voltage ranges. The LM5017 integrates an undervoltage lockout (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. Peak current limit detection circuit is implemented with a forced off-time during current limiting that is inversely proportional to VOUT and directly proportional to VIN. Varying the current limit off-time with VOUT and VIN ensures short-circuit protection with minimal current limit foldback. Additional protection features include thermal shutdown with automatic recovery, VCC and gate drive UVLO, minimum forced off-time, and remote shutdown.