Good day all.
Now we are facing to strange phenomenon on our new sensor product that uses ADS131E08. It uses ADC circuit to sense a physical value.
We would like to use out-of-range detect function of ADS131E08 to find circuit disconnect.
But it not works as we expected.
Our setting conditions are below.
DVDD 3.3V
AVDD 5.0V
AVSS 0V
VREFP 5.0V
VREFN 0V
COMP_TH 010 (upper 90%=4.5V / lower 10%=0.5V)
With this condition, we applied for IN1P=0V, IN1N=5.0V.
In that case, both input voltage level exceed threshold vale that fixed by COMP_TH register.
But corresponding error bits in FAULT_STATP and FAULT_STATN are not set. (Keep "0".)
On the other hand, when we apply IN1P=5.0V, IN1N=0V, both error is detected in error register.
Is it proper operation?
By other test, it looks like as below.
INxP(x:1-8) signal is compared with only high side threshold value.
INxN(x:1-8) signal is compared with only low side.
From specification sheets of ADS131E08, it seems that any inputs are compared with high and low threshold value at the same time.
Please let me know my understanding is correct or not.
Best regards.
