MC56F84763VLH - Wrong values for ADC connected to PIN25

[M4k5]

Hi,

we are using the MC56F84763VLH in one of our projects. We now already had multiple issues with the ADC connected to PIN25. The ADC is reporting wrong values no matter what voltage is applied to the pin. 

In the same project we are using multiple pins for measuring voltage and current and therefore the layout of the pcb and the code is the same for other pins. That means if the failure would be caused by the layout or by our code, it would be very unlikely that alwas PIN25 is failing. In the last batch we orderd had three defective units with exactly this error. 

The ADC value reported by those three defective units on PIN25 are all different. Measuring the voltage on the pin confirms those wrong values. Also manually applying voltage to the pin doesnt change the value. It just remains stuck. 

Does anybody had a issue like this or is this a known issue?

Thanks Already

Maximilian

[xiangjun_rong]

Hi,

I have download the errata for MC56F84xxx, but it does not lists the any issue for the ANB1 pin.

https://www.nxp.com.cn/docs/en/errata/MC56F847xx_2N27E.pdf

I think this is the pin configuration

1)enable GPIOB gated clock

SIM_PCE0|=1<<5;

2)configure GPIOB1 as analog function ANB1

GPIOB_PER|=1<<1;

Can you tell us the defective rate for all your board?

BR

XiangJun Rong

[M4k5]

So is there a solution for this problem?  

[xiangjun_rong]

Hi,

I am sorry, I have not idea for your issue.

BR

XiangJun Rong

[M4k5]

Hi,

I also looked through the errata sheet already and didnt find anything.

I checked the pin configuration and it is exactly as you mentioned it.

We have ~0.6% defective units with exactly this error. 

Thanks

Maks