Electrical / Electronic Theory and Learning Center > Learning Center Miscellaneous
MOSFET driver issue
Hakasays:
--- Quote from: Grumpy on 2022-09-12, 00:02:20 ---Thanks Hakasays!
This was the issue. 10k at the input to ground and it shuts off when floating. They could have mentioned this in the datasheet...
Funny thing is that I had a 10k at the input when I tested it and then forgot the 10k at the gate, so I moved it.
--- End quote ---
The gate capacitance is so low and those drivers are such high impedance that it probably charges capacitively from its own drive voltage.
Glad to help ;)
Grumpy:
--- Quote from: Hakasays on 2022-09-12, 02:37:27 ---The gate capacitance is so low and those drivers are such high impedance that it probably charges capacitively from its own drive voltage.
Glad to help ;)
--- End quote ---
I believe you are correct. You can see the voltage bleeding off (from 12v down to zero) when you connect the resistor to the input.
I wanted to use a very fast TI driver but only a few were available and long lead time.
Grumpy:
10k wasn't always working reliably so I Googled it:
Found out how to calculate the minimum resistance here:
https://electronics.stackexchange.com/questions/60427/calculating-the-pulldown-resistance-for-a-given-mosfets-gate
I'm betting it will be pretty low ohms.
Navigation
[0] Message Index
[*] Previous page
Go to full version