G2 18v25 capacitor

Hello, first, i’m french so sorry if my english is bad.
I just bought a G2 18v25 high power controler and i would like to know wich capacitor i have to use. i’m not very good in electronics calcul.
The power supply is a PC supply, delivery 12v at 20A. Motor is a drill motot, normaly for 18v and controled with a 20A mosfet, and pwm source an arduino at 23kHz.
I dont want to damage the 18v25 during the first test, if the capacitor is wrong.
the biggest one i have is a 220uF, 63V. can i use this one? or put two ( or tree) in parralel?
otherwise, i can unsolder two 330uf 50V or two 680uf 200V from old pcb.
wich posibility sounds greater?
thank you very much if you can help me.

(Ps : realy sorry for my bad english)

i have an other question.
For testing my sketch from arduino, can i use 5V supply (Vin-GND) from the PC supplu( 5v-30A) to powered the motor ( and use smaller motor)?


Your 220uF, 63V capacitors are probably fine, and you could use a few of them in parallel like you mentioned to get higher capacitance and be extra safe. As for your second question, the G2 18v25 high power controller’s operating voltage range is from 6.5V to 30V, so your 5V PC power supply would not be sufficient.


Thank you very much Rocky for your answer. I tested the controler ( with a smaller motor) ans all works fine with the 220uf Capa, if necessary, i would add some other in parallel.
I have another question please.
As mentionned, the power supply is a 12V 20A from Pc supply. if i understood correctly, the capacitor( inclued on the controler and the one i addeed) might increase the current trought the controler. So is it neccessary to put a resistor between GND and vref to preserve the G2 18v25?
thanks and have a good day


Adding a resistor is not necessary and using large capacitors on the input of the driver does not really increase the need for it. Adding those capacitors will just increase the initial inrush current that is drawn from your supply when first powering up the driver. A resistor can be added to the VREF node to decrease the driver’s current limit and help protect it from large motor current draws, for example in situations like a motor stalling. Adding a resistor is discussed in the Current sensing and limiting section of the G2 18v25 product page.