Hi,
My application is to detect the AC voltage presence using Continuous high or low signal.
I am using a Non-Isolated power supply with 120mV Vp-p as supply.
circuit is as shown below where I need GPIO continuous Hi or Low
With this when voltage detected it is not going to zero instead it is some where around 0.6-1.2v
And some times there is a noise on IO which is Reaching Vp-p as much as 32V as shown below
I Tried Below circuits , with TVS
The 34v noise clamped and Iam only getting Ripple of 0.4-0.6v at AC Presence
when I used Schottky arrangement of GPIO As shown below 34v noise clamped but ripple was 0.8-1.2v
now my question is which arrangement is better for my GPIO stability?
TVS of Schottky configuration? because rise time of noise is lessthan 10nS. even TVS is giving better performance Iam not sure will it sustain those type of continuous noise!
and My TCA6424A is stucking / not responding when I get this noise. but with TVS/ schottky arrangement its not happening but when The GPIO state is above
1v instead of ground Its false triggering and some times stucking.
is there any way I can make this low level to 0V or less than 200mV.
