50V to 5V @7A Synchronous Buck (Step-down) Converter

This module is a non-isolated 7A DC-DC converter. The module can convert any DC voltage between 7V to 50V to a 5V DC with load current up to 7A. The project has been designed around LM5116 Wide Range Synchronous Buck Controller IC. The design includes 6uH toroid inductor and two N channel MOSFETS. The operating frequency is 250 KHz.

The LM5116 is a synchronous buck controller intended for step-down regulator applications from a high-voltage or widely varying input supply. The control method is based upon current mode control utilizing an emulated current ramp. Current mode control provides inherent line feed-forward, cycle-by-cycle current limiting, and ease-of-loop compensation. The use of an emulated control ramp reduces noise sensitivity of the pulse-width modulation circuit, allowing reliable control of very small duty cycles necessary in high-input voltage applications.

The operating frequency is programmable from 50 kHz to 1 MHz and the LM5116 drives external high-side and low-side NMOS power switches with adaptive dead-time control. A user-selectable diode emulation mode enables discontinuous operation mode, for improved efficiency at light load conditions. A low quiescent current shutdown disables the controller and consumes less than 10 µA of total input current.