LPC845 HVQFN33 ADC won't provide correct counts

[scottbates]

Hi,

I have an LPCXpresso845MAX board. I am using ADC0 and ADC9 to acquire some signals. I started with the example code ADC_Seqa_Seqb and was able to get both channels to work. I have a desgined board that has the HVQFN33  version of the chip on it. I can not seem to get the ADC to work with the same code as mentioned above. The ADC returns counts of about 15 on both channels when I should be getting counts on the order of 350. I know the board design works because I previously used it with an lpc824 (ADC0 and 9 worked fine in this case). The Xpresso845MAX board has the 64 pin chip on it. Is there something special I need to do for the HVQFN33 chip? I have several builds of my board with the 845 on it and they are all behaving the same way. 

Thanks for the help.

[srchethan]

We are also facing the same problem

LPC845(HVQFN33) ADC is not Working

We downloaded SDK_2.8.0_LPC845 library for LPCXpresso845MAX and tested adc,adc functionality is working properly.
We designed board based on LPC845(HVQFN33) Package.We tested our board with the same library for adc application,we are not getting any adc value.(always showing adc count value as 12)

[jeremyzhou]

Hi Scott Bates,
Thank you for your interest in NXP Semiconductor products and for the opportunity to serve you.
It seems a bit weird, the ADC is identical on all LPC845 parts, I was wondering if you can provide more information about this phenomenon, for instance, screenshots, etc.
Have a great day,
TIC

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