Kris Sielski

LPC824 ADC Offset

Discussion created by Kris Sielski on Mar 23, 2018
Latest reply on Apr 11, 2018 by Simon Wood

I seem to be getting a large offset from the ADC on the LPC824.

 

I have the LPCXpresso824 eval board (OM13071) and I shorted the ADC input to GND.  I am using the default LPCopen ADC demo code.   The output of the ADC is 0x02C, which is about 35mV  [(3.3/4096)*44].  I have verified this on several different demo boards - all having an output value when the input is grounded.

 

I have verified that the calibration is being performed and have verified that the initialization and operation of the LPCopen code follows the users manual.

 

Am I doing something wrong or missing something that the ADC does not output zero when the input is grounded?

 

Thank you,

Kris

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