ESP8266 Community Forum

- Fri Sep 13, 2019 1:21 pm #83785 I am building RGBW controller for my room I will be using ESP32 with 4 MOSFET for each channel. I want to know which is best for fast switching do I need to use MOSFET driver IC such as ICL766 with IRFZ44n or should I use lower VGS MOSFET such as AO3400 ? Or something entirely different? I'm open for suggestion.
what are the cons and pros for both, since it's only one time investment cost is not the issue.
I prefer smd components.

- Thu Sep 19, 2019 1:32 pm #83849 I am very much pro gate driver in almost every situation.

The ESP8266 has push-pull GPIO pins so it is able to drive a mosfet directly and it even can sink/source 30 mA. BUT I'd rather use a gate driver because a gate is driven much stronger than a GPIO ever can, the IR4426 can sink/source 8 A to get the charge in/out of the gate. This will make the mosfet switch much faster and make much more robust (larger safe operating area). Besides that, most mosfets (i.e. "logic" variants) will have a Vgth of < 3.3 V which sounds good, but mostly it will not be completely saturated until driver with something 9 V, even the "logic" ones. See datasheets. If you use a gate driver, you can feed it with 9 V or even 18 V (max) and you have the choice of almost every mosfet you like, you're not limited to logic level ones.

Also the gate driver input has a schmitt trigger (at least the IR4426 does), which helps making the switching transition even quicker.

Mosfet gate drivers don't have to be expensive $ 1-2 is normal.

Did you know that if you have a small load, you can even use the gate driver without external mosfet? The builtin driver fets can switch quite a bit of load, it surprised me!