Tool/software:
Hello Team,
I have two sensor inputs. One is differential output connected to channel A of the ADC3908D025 ADC and one is single ended output connected to channel B of the ADC. VCM pin is not used. ADC is configured as DDR (M0 = LOW), ADC data (M1 = LOW), and for the differential input, M2 = GND i.e. 2s complement. I am getting the differential data correctly. However, for the single ended output I am not getting the readings properly. The single ended signal has a DC offset of 900mV and spans from 266mV to 1.4V. I have tried M2= AVDD, i.e. binary offset, but the reading are different in the sense DC offset reduced to 200mV from 900mV and highest peak reading is correct at 1.4V, but lowest peaks are clipped to 0. I tried M2 = 1V, but there also, we are getting some negative values whereas the signal is completely positive wrt GND of ADC. Can you help a bit in understanding why the problem is occurring and suggest how to interface the single ended signal to the ADC.
Second doubt is, internal reference of the ADC is 1.2V, but can we give a signal higher than 1.2V since AVDD is 1.8V? In that case, what will be the output?
Thanks and Regards,
Bhargav Saikia.
