Other Parts Discussed in Thread: ADS1198, ADS1298
I used ADS1298 for a while and now I'm trying to use ADS1198. As I know the only difference is 16-bit vs 24-bit and some register contents. Schematics is the same which was used on ADS1298 and is posted below.
The problem I have with ADS1198, is that I always receive maximum values (data saturated probaby) on output and I don't know why.
Electrodes are connected to ECG simulator which works OK tested with another ECG.
I moved further and I used 1.5V battery and potentiometer and put directly to pins for xP and xN of channels and values are always max positive or max negative no matter how potentiometer is rotated. I've set gain to 1 to all registers but on success.
Even, if I short inputs by setting 0x11 to all channels, I see only max and min values at output.
I've measure all VCAP voltages and everything looks OK. Reference voltage is 2.4V and clock is internal 2.048 MHz.
Voltages:
AVDD: 3.3V
DVDD: 3.3V
VCAP1: 1.2V
VCAP2: 1.65V
VCAP3: 5.1V
VCAP4: 2.4V
What could be wrong here?
My registers settings and schematics are below.
Thanks for any help, I'm working on this problem now for 2 days without success.
The same board with ADS1298 worked OK.
Edit: When I rotate my potentiometer, returned result is always the same, but LEAD off status changes randomly.
Edit 2: I've set channels to temperature sensor measurement and output is always set to max value possible: 0x7FFF.
