Outputs and switching

IRLZ44N MOSFET with ESP32

A MOSFET switches or dims a DC load silently, where a relay would click and could not do PWM. A common use is a 12 V LED strip or fan controlled from a display board. It goes on the low side: load to +12 V, load to drain, source to ground, and the ESP32 gate signal turns it on.

The IRLZ44N is often called logic level, but be careful at 3.3 V. Sources disagree, and its best on-resistance is reached with about 5 V on the gate. At 3.3 V it can stay partly open and run hot at high current, so it is fine for small loads and not a safe choice for many amps. For larger loads use a gate driver, or a MOSFET that is specified at 3.3 V.

Add a resistor of about 100 to 330 Ω in series with the gate, and about 10 kΩ from gate to ground, so the load stays off while the ESP32 boots. Inductive loads such as fans, valves and motors need a flyback diode like a 1N4007 across them, with the cathode to +12 V. The grounds of both supplies must be connected. LCD Ultra Pro can set a PWM value on a pin from a slider or rule, without code.

const int GATE_PIN = 5;
const int FREQ = 1000, BITS = 10;

void setup() {
  ledcAttach(GATE_PIN, FREQ, BITS);
}

void loop() {
  for (int d = 0; d < 1024; d += 8) { ledcWrite(GATE_PIN, d); delay(10); }
  for (int d = 1023; d >= 0; d -= 8) { ledcWrite(GATE_PIN, d); delay(10); }
}

Use this information at your own risk. It is for general guidance only: the example code compiles, but it has not been tested on every part, and modules differ between sellers. Check the manufacturer's data before you build. Product names belong to their owners, and LCD Ultra Pro is not affiliated with them. See our Terms.