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ADC12DL080 Single-Ended Operation

Marko Rman
Prodigy 20 points

I'm trying to figure out how i need to connect this adc. I have 0-2V signal that i want to convert. if i understand from the datasheet:

However, if single ended-operation is required and the resulting performance
degradation is acceptable, one of the analog inputs should be connected to the d.c. mid point voltage of the
driven input. The peak-to-peak input signal at the driven input pin should be twice the reference voltage to
maximize SNR and SINAD performance (Figure 41b). For example, set VREF to 1.0V, bias VIN− to 1.5V and drive
VIN+ with a signal range of 0.5V to 2.5V.

So in my case i would need to connect Vin- to 1V and drive the Vin+ withy my 0-2V signal. Is this correct? 

  • 0
    TI__Expert 4340 points

    Yes, you are correct that Vin- should be 1V. The input common-mode range of the device supports this value. And in your case, the VREF will also be 1.0V.

    Regards, Josh

  • 0 in reply to Joshua Carnes
    Prodigy 20 points

    One more question about that. Datasheet says that input common volate should be in range of 1V to 2V. Would't in my case when Vin- is 1V and Vin+ 0V, common voltage drop to 0.5V ? Can device still operat outside of specified range?

  • 0 in reply to Marko Rman
    TI__Expert 4340 points

    Yes, you are correct. I was still in 'differential mode' when I answered previous. Since you are driving it single-ended, the input common-mode range of the converter must be half that of the input signal amplitude range. Your signal range is 2Vpp, therefore the common-mode range must be 1V wide. Based on the input range of the ADC, this can be done, but only if Vin- is set to 1.5V.

    Regards, Josh