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ADuC7060 _ADC4 output noise ?

Question asked by Terumasa on Mar 14, 2017
Latest reply on May 4, 2017 by barryzhang



Please let me know your advice about ADC4 output of ADuC7060.

Our customer uses EVAL-ADuC7060 at below condition.



Primary channel and Auxiliary channel is measured  alternately.

Output data of Primary channel is OK  ,

but the data of Auxiliary channel is periodically swing about  12274000LSB +- 1000LSB.


When auxiliary channel only is measured ,   ( primary channel is disabled)

above problem is not appeared  and result is about 12274000 LSB +- 100LSB




Is there any limitation of using both primary channel and auxiliary channel ?

If you need measurement data , please let me know your e-mail address because it is cutomer's data.


Measurement sequence

Measured channel is below sequence.

ADC0:1 - > ADC4 - > ADC2-> ADC4 -> ADC3  -> ADC4   - >  ADC0:1  ....


Channel settings

ADC0:1  = RTD

ADC2 and ADC3 : another sensor output voltage

ADC4:   0.88V from reference  voltage generator

ADC5 is connected to AGND.


Board switch setting


Other switch: Open


Register settings of both channel measurement

ADCMDE = 0x81;

ADCMSKI = 0x03;


ADC0-1: 0x8414

ADC2:   0x8580

ADC3:   0x85C0


ADC4:   0x8B00


ADCCFG = 0x0000;

IEXCON = 0x42;


Register settings of auxiliary channel  only measurement

Below change from above settings

ADCMSKI = 0x02; 

ADC0CON = 0x0000


Please let me know your advice.


Best Regards,