DFRobot MOSFET Power Controller DFR0457 - freewheeling diode
Mario.Kazana 2026-05-27 23:34:35 303 Views1 Replies I have a DFRobot DFR0457 MOSFET module where there is this information:
The Gravity: MOSFET Power Control Module is a versatile component that allows low-current microcontroller units (MCUs) such as Raspberry Pi and Intel Edison to control high-current devices. It operates with a wide voltage range of 5~36V VIN and can handle up to 20A of current. The module is equipped with a PH2.0-3P Gravity interface, making it compatible with various Arduino IO shields for a plug-and-play experience. Ideal for robotics and other applications requiring fast switching up to 1KHz, it is crucial for projects involving inductive loads like motors and solenoids to use a freewheeling diode to prevent back EMF damage. This module is a critical component for anyone looking to expand the capabilities of their MCU projects.
How do I properly add a freewheeling diode to switch inductive loads (motors, electromagnets, relays)?
Where and how should I correctly insert a protective diode to protect the module, and what is the best diode for this purpose?
Hi, add the freewheeling diode directly across the inductive load.
For DFR0457, the load should be connected between VOUT and GND. Connect the diode in parallel with the load: the cathode/striped end goes to VOUT, and the anode goes to GND.
During normal operation the diode is reverse-biased. When the MOSFET turns off, the coil current can recirculate through the diode instead of creating a high back-EMF spike.
For diode selection, choose a reverse-voltage rating higher than your supply voltage and a current/surge rating suitable for the load. A 1N400x is usually fine for small relays or solenoids. For PWM, motors, or faster switching, use a Schottky or fast-recovery diode with enough current margin.
Yx 
