Brushless motor driver

[Shlomi9137]

Hello, I have a Brushless motor driver PCB
A quantity of 70 such drivers and according to their original design

There are 3 units of THT Electrolytic capacitor 100V 220uf on it

And it has 6 units of Power Mosfet 100V 107A

Because it is 100V, it can be used with a motor of up to 75V

And I don't need 75V, I'm going to use 36V

And I checked about THT Electrolytic capacitor 63V 220uf

And also regarding Power Mosfet 63V 100A

And according to the Pitch, both the capacitor and the Mosfet of the 63V are compatible with the PCB

I'm asking this question because I want to save money and not just buy products that give a much larger consumption than I need and I don't even use that amount. My question is, can I solder the two things I mentioned to the board?

Thank you

[Peter BENSCH]

You are discussing a BLDC design with higher power, where you cannot simply replace one MOSFET with another. Depending on the gate driver and drive frequency, other components may also have to be adapted, e.g. gate resistors. You may even have to change the timing of the driving PWM pulses. Other capacitors are also providing different parameters (ESR, parasitic inductance, etc.), so that they cannot simply be replaced without risking the destruction of the running system.

A more precise statement can only be made after considering all parameters (schematics, existing board, etc.). I therefore recommend contacting local support (engineering office, local distributor, etc.).

Hope that helps?

Regards
/Peter

[Shlomi9137]

First thank you for replying

This is your company's PCB, STMicroelectronics, if I send you the schematics and bill of materials of the board, can you help me with that?

[Peter BENSCH]

If it's ST boards, I'm sure one'd be happy to take a look at the alternatives here. Please mention the type of board or the URL to it, as well as the URLs to the data sheets of the alternative devices (MOSFETs, capacitors, etc).

[Shlomi9137]

Hi again i added everything you mentioned

Board: https://www.st.com/en/evaluation-tools/evspin32g4.html#overview

Alternative devices links

Power mosfet: https://www.st.com/resource/en/datasheet/stl50n6f7.pdf

Capacitor: https://www.we-online.com/components/products/datasheet/860040775010.pdf

[Peter BENSCH]

It should be possible to use the STL50N6F7 instead of the STL110N10F7 if the gate resistors are adjusted to be approx. 2.2 times larger in accordance with the significantly smaller Ciss. Depending on the connected motor, you should take into account that the maximum ripple current of the 860040775010 with 1.1A is only half that of the electrolytic capacitors 860040878017 used in the EVSPIN32G4.

Good luck!
/Peter

[bogdandavyd]

Looks like you're working on getting a bldc fan motor running with an STM32. If you're considering a driver, the STSPIN series could be worth checking out. They integrate control logic and can simplify your setup. If you're aiming for sensorless control, make sure to configure your BEMF sensing correctly. Also, STM32's motor control SDK has useful examples that might help with implementing different control strategies.