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ADS1248EVM / AIN0 read value

Guru 20090 points
Other Parts Discussed in Thread: ADCPRO

Hello,

Our customer is evaluating ADS1248EVM via ADCPRO software.
Currently , they measured the AIN0 voltage as 2.048V always.
Could you please let me know this reason?

2.048V is external reference voltage for REF1P.
We could measure 2.048V If we changed the reference from REF1P.

Best Regards,
Ryuji Asaka

  • Ryuji-san,

    Is the customer having problems with any other inputs other than AIN0? What are the inputs connected to when it gives a result of 2.048V. Is AIN0 selected for AINP and AIN1 selected for AINN? Generally a reading of 2.048V is the maximum full scale and it may mean that the input is either too large or floating.

    I would start with a test to see if the input is working on the ADC. Have the customer start up ADCPro, select the ADS1248EVM plugin, and start the MultiScope test tool. At startup, the AIN0 input should be AINP and the AIN1 input should be AINN. Then turn on the VBIAS for both AIN0 and AIN1. This should tie the inputs together inside the multiplexer.

    Then take a reading. I've selected a data rate of 320SPS because at a data rate of 5SPS, I'd have to wait almost 2 minutes to get a result. The customer should get a reading close to 0. I get this result:

    Have them test this and let me know if they are able to get some non-full-scale result.

    Joseph Wu