topic Re: PTC2 pin cannot be pulled to 0 level in S32K

PTC2 pin cannot be pulled to 0 level

FAR1234 — Wed, 20 Aug 2025 14:21:15 GMT

Dear NXP experts,

I had PTC2 (yellow waveform) and PTE7 (blue waveform) ports periodically reverse, and found that PTC2 (yellow waveform) could not drop to 0V, as shown in the following figure.

The configuration parameters of PTC2 and PTE7 ports are as follows:

I look forward to your reply.

Re: PTC2 pin cannot be pulled to 0 level

FAR1234 — Wed, 20 Aug 2025 15:05:44 GMT

I would like to add that my MCU is S32K142W.

Re: PTC2 pin cannot be pulled to 0 level

VaneB — Thu, 21 Aug 2025 18:43:04 GMT

Hi @FAR1234

The S32K1xx Data Sheet (Rev. 14) defines VOH and VOL at specific current levels. If your circuit draws more current than allowed, the output voltage may not reach the expected high or low levels.

Also, not all pins have the same drive strength. Some are designed to handle more current. You should check the I/O characteristics section in the datasheet for details.

For a deeper understanding, I recommend looking at the “Output Characteristics” section in Application Note AN2434. Even though it is for the HCS12 family, it gives useful insights into how MCU pins behave.

BR, VaneB

Re: PTC2 pin cannot be pulled to 0 level

FAR1234 — Fri, 22 Aug 2025 08:06:56 GMT

Hi @VaneB

I am glad to receive your reply.

Based on your suggestion, I have consulted relevant technical materials and conducted relevant tests, but the problem has not been resolved.

yellow waveform :PTC2;

blue waveform : PTC3;

Let me add the background of my port usage:
My application is to configure PTC2 as FTM0_CH2 channel. Currently, this PTC2 pin is only connected to the oscilloscope probe and not to any other load, so there is no problem of output current exceeding the standard.
And it was me who configured the six channels of FTM0, only this FTM0_CH2 has a problem, while the other channels are normal.
I tried to increase the driving capability of PTC2 to a level of 20mA (as shown in the figure below), but the problem still persists.

Best regards

Re: PTC2 pin cannot be pulled to 0 level

VaneB — Fri, 22 Aug 2025 21:56:31 GMT

Hi @FAR1234

It seems like your configuration is all set up correctly, and the issue is only happening with PTC2. Just to rule out any hardware-related issue, could you try routing the same signal to a different pin and see if the behavior changes?

It might also be worth taking a quick look at the PTC2 pin itself for any signs of physical damage or soldering issues.

Re: PTC2 pin cannot be pulled to 0 level

FAR1234 — Sat, 23 Aug 2025 03:06:07 GMT

Hi @VaneB

I am glad to receive your reply.

I routed FTM0_C2 to PTD0, and the output of PTD0 is normal.

By carefully examining my development board, I found that PTC2 was connected to the CAN chip as CAN0-RX on the expansion board. After removing the CAN chip, PTC2 returned to normal.

Thank you very much for your guidance.

Best regards