Futterama
Member
Hello forum,
I'm working on a simple motor control using a PIC12F629 and 2 dual MOSFETs, a P-channel FDS6875 and a N-channel FDS6898AZ.
When I say "simple motor control" I mean full forward, stop and full reverse, no PWM is used. The controller is not speed critical, since it's for a small RC toy car with a small motor with a stall-current of 1,3A at 3,6V. The PIC is also running at 3,6V.
I have connected the MOSFETs in a H-bridge design, and have connected pull-up resistors on the P-channel gates, and pull-down resistors on the N-channel gates (56k).
The PIC is driving the gates directly.
The problem is, the PIC cannot drive the gates without a series resistor. This puzzles me. I know the gate is like a capacitor, and the PIC output current is max 25mA. But in other projects, a PIC10F206 is driving a SI2302DS MOSFET without problems.
Can some of you explain to me what my problem is?
Here is some links to the MOSFET datasheets if nessasary:
https://www.electro-tech-online.com/custompdfs/2007/11/FDS6875.pdf
https://www.electro-tech-online.com/custompdfs/2007/11/FDS6898AZ.pdf
Thanks.
I'm working on a simple motor control using a PIC12F629 and 2 dual MOSFETs, a P-channel FDS6875 and a N-channel FDS6898AZ.
When I say "simple motor control" I mean full forward, stop and full reverse, no PWM is used. The controller is not speed critical, since it's for a small RC toy car with a small motor with a stall-current of 1,3A at 3,6V. The PIC is also running at 3,6V.
I have connected the MOSFETs in a H-bridge design, and have connected pull-up resistors on the P-channel gates, and pull-down resistors on the N-channel gates (56k).
The PIC is driving the gates directly.
The problem is, the PIC cannot drive the gates without a series resistor. This puzzles me. I know the gate is like a capacitor, and the PIC output current is max 25mA. But in other projects, a PIC10F206 is driving a SI2302DS MOSFET without problems.
Can some of you explain to me what my problem is?
Here is some links to the MOSFET datasheets if nessasary:
https://www.electro-tech-online.com/custompdfs/2007/11/FDS6875.pdf
https://www.electro-tech-online.com/custompdfs/2007/11/FDS6898AZ.pdf
Thanks.