IRF520 MOSFET driver module
IRF520 MOSFET module pinout (SIG, VCC, GND, VIN, V+, V−), why it barely switches from 3.3 V or even 5 V, the flyback diode it lacks, and logic-level alternatives.
Community draft — report a mistake
3.3 V or 5 V? The IRF520 is not a logic-level MOSFET: it needs about 10 V on the gate to switch fully. From 5 V it handles roughly 1 A; from 3.3 V (ESP32, Pico) it barely turns on. For 3.3 V boards use a logic-level module (AOD4184 / D4184, IRLZ44N).
The module puts an IRF520 N-channel MOSFET on a board with screw terminals, so a GPIO can switch a DC load — an LED strip, 12 V fan, small pump or solenoid lock. The MOSFET sits on the ground side (“low-side switch”): the load’s + goes to the supply and its − is pulled to ground when SIG is HIGH. PWM on SIG dims LEDs or slows fans.
The catch: the IRF520 needs about 10 V on its gate to switch fully on. Arduino’s 5 V gets it partly there, enough for loads up to about 1 A; the 3.3 V from an ESP32 or Pico leaves it mostly off. The “5 A / 24 V” in listings only applies with a proper 10 V gate drive.
For new builds, buy a logic-level module instead — the blue D4184 (AOD4184) MOSFET module switches fully from 3.3 V and handles 10 A+. And DC only: never use any MOSFET module for 230 V AC.
Prices are indicative (Nov 2026) and vary by seller.
Pinout
| Pin | What it does |
|---|---|
SIG | Gate control from your GPIO (PWM is fine for LED strips and fans) |
VCC | Not used by the MOSFET on most boards — can be left unconnected |
GND | Ground — shared by the signal side and the load supply |
VIN | Load supply + in (screw terminal), DC only |
V+ | Load + out (connected straight to VIN) |
V- | Load − out — the MOSFET switches this side to ground |
Common errors
Load runs weakly and the MOSFET gets hot
The gate isn’t driven hard enough, so the MOSFET sits half-on. Drive it from 5 V at most for small loads, or swap to a logic-level MOSFET module.
Board resets or the MOSFET dies when a pump, solenoid or motor switches off
Inductive loads kick back. The module has no flyback diode — fit a 1N4007 (or 1N5819) across the load: band to V+, other end to V−.
Load never switches off fully
The gate is floating while the board boots. Add a 10 kΩ resistor from SIG to GND.