Tool/software:
1. Testing for the AFE output setup
- All the signal VOUT_S<0>, …, VOUT_S<15>, VOUT_S<16>,…,VOUT_S<31> are tied together, and could be adjusted by a on board pot
- The another signal ( DAC-OUT0,…, DAC-OUT31 ) is controlled by separate DAC, which could be output 0 – 1.4V with 10 bits resolution
- AFE input: AFE-AIN0 = DAC-OUT0 + VOUT-S<0> / 2
- CLAMP-H2 = 1.17V, and CLAMP-L2 = 0.375V. They are used to protect the AFE inputs for out of range signals
2. Problems Observed for CH to CH influence
- If we set all the VOUT-S<> to 1V, and DAC-OUT<> to 0.95. All the channels are sampled to a value closed to -300 with certain gain.
- Then we change DAC-OUT0 to 0.7V, and the CH0 reading is closed to -1600; However other channels in AFE1 readings are jumped to around -700, and all the channels in AFE2 reading are still around -300. They are using the same external reference 1.4V.
- Do you see anything wrong with this? Or we overlooked something in the register settings?
