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AD7679 Drive by Single-Ended Signal

Hi All,

 

Does the AD7679 accept the single ended signal input?

Actually, IN- terminal will be connected to GND and 0-5V range signal will be driven to IN+. Is this configuration works okay?

I know that the AD7691 must be driven by differential signal only, because it has common-mode input range specification. The AD7679 doesn't have the common-mode range limitation specification.

 

Best Regards,

Ricky

  • Hi Ricky,

    We can't put one input to GND in true differential ADC as this would violate the common mode restriction. It does not specified the input common mode in the datasheet. However I would recommend to keep the common mode within +/- 100mV of Vref/2. May I ask what application  there are pseudo SAR input if you are interested in those.

    regards,

    LLoben

  • Hi Gnib-san,

     

    Thank you for your response.

    My customer's application using AD7679 is temperature sensor signal measurement, he said.

    I would like to hear more about why those high speed sampling ADC is required for his application, in later date. 

    Anyway, in responding to my customer's inquiry (high resolution single ended input ADC), May I chose AD7641 18 bit ADC which accept single ended input? The data sheet Table 2 indicate that the Operating Input Voltage is −0.1 V to AVDD at signal is to VIN+ and VIN− to AGND. 

     

    Best Regards,

    Ricky

  • Hi Ricky,

    AD7641 is the same input configuration of  AD7679 differential ADC . If he wants SE(pseud-diff)ADC we can recommend the AD7988-5 or some similar SE ADC in the same family of AD7679 like the AD7666.

    regards,

    Lloben

  • Hi Gnib-san,

     

    Thank you very much for your advice.

    I will talk to my customer based on your advice.

     

    Best Regards,

    Ricky