ADS54J60 supports DC-coupling with offset
Hi,
Let me question whether the analog input of the ADS54J60 supports DC-Coupling.
We attach circuit configuration, input waveform, output data diagram.
Connect the +IN terminal of the differential amplifier to GND,
Input the signal to the -IN terminal.
For VOCM of the differential amplifier, input 2.0V from 22pin (VCM) of the ADS54J60.
We gave the following two types of inputs and confirmed the AD-conversion data.
case1
Connect a 50Ω resistor to the -IN terminal of the differential amplifier and input 0V.
Make sure -OUT and + OUT of the differential amplifier are both 2.0V (VCM voltage).
The result of A / D conversion for 0V has no problem.
case2
Input the DC-voltage (for example 200mV) to the -IN terminal of the differential amplifier.
A DC-offset voltage is applied to VCM at -OUT and + OUT of the differential amplifier.
The voltage is input to the ADS54J60.
The result of AD conversion at that time does not become DC-voltage.
A waveform like the attached waveform is output.
Question1
Is the analog input of the ADS54J60 compatible with DC-Coupling?
(Input offset voltage is several hundred mV)
Question2
When DC-coupling is possible, is it necessary to input a signal with 2.0V as common to the analog input terminal?
If DC-Coupling is not possible if an offset of several hundred mV is applied to the signal,
It is also possible to change to AC-Coupling.
best regards
