Hi,
I am using ADS1158 and on the same board a conditioning circuit is connected to the analog outputs MUXOUTP and MUXOUTN. The outputs of the conditioning circuit are connected to the analog inputs ADCINP and ADCINM.
1st test: BYPAS bit set to "0":
- voltages could be measured properly but with some drop because of the low input impedance of the IC and the high output impedance of the circuit connected to the analog channels.
2nd test: BYPAS bit set to "1" keeping the rest of the configuration as it is:
- totally wrong measurements (so small values).
NB: I verified with the oscilloscope that the analog outputs from the ADS1158 are correct and verified that from the outputs of the conditioning circuit we have the same signal and its reaching the ADCINM and ADCINP pins on the board.
The main settings are:
- Scan mode is configured with some single ended channels and some differential channels (same issue for both kind of channels).
- DRATE[1:0] = 0x3
- DLY[2:0] = 0x7
- CHOP = "0"
- Reference voltage is soldered properly and it's exactly 4096 mV : (VREFP = 4096 mV, VREFN = GND)
- AVDD = 5V, AVSS = GND.
Could you please help? Is there some additional detail that I am missing?
Regards.
