LPC4357 ADC Issue

[dshaikh]

Hello! 

We have used two out of eight dedicated pins of internal ADC of lpc4357 controller and remaining six pins are left unconnected. But while operating at 55 deg temperature one adc pin got latched to 3.3 V.

Even resetting the controller and strong pull down at adc pin doesn't affect, the pin was continuously latched to 3.3 V. Then we have directly shorted adc pin with ground and So it started working. Can any one tell what will be the reason for these wired scenario?

Thanks in advance!

[dshaikh]

Thanks soledad,

Please find the attachment for schematic. The sensing circuit is on other board and controller is on other.

Thanks in Advance!

[soledad]

Hi,

We need to understand which PIN, or terminal, it is the one that it is presenting this weird scenario, and  if there is something attach to this PIN. Could you please mention which pins are you using and which is the pin that has this issue?

Could you please share your schematic file?

Have a great day,
Sol

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