Dear Technical Support Team,
I have a question about ADC34J45IRGZR.
When no signals for analog input on 4ch, digital values have variation between Ach and Bch and Cch and Dch.
In this case, the average of digital values on FS 2Vp-p are below.
Cch looks like bigger than other channels.
Ach 1.1mV
Bch 1.2mV
Cch 5.2mV
Dch 0.7mV
But datasheet page.8 shows that Offset error(Eo) is from -20mV to 20mV.
Is it shows above result?
Dose Offset error(Eo) have variation between 4ch?
I guess that the offset error(Eo) specification is for each individual channel (+/-20mV).
■environment information
・Other devices on same board are a little variation between Ach and Bch and Cch and Dch like from 1.2mV to 2.0mV.
・ENOB shows 11.3bit on datasheet, so LSB 3bit noise is around 1mV.
Variations of Ach and Bch and Dch digital values looks appropriate except for Cch.
・Dither is enable on all channel.
・Our board schematic refer to ADC34J45EVM schematic.
・2 cases test for no analog input,
One is connected pre-circuit to analog input of ADC.
Second is cable open.
Digital values of both cases are almost the same.
Regards,
y.i
