The main question here is (explanation will follow):
Is there a way to filter out low voltage oscillations (>10MHz) on pins that have to stay high for the system to function? Oscillations are induced by EMI emitted by power circuit during relay bouncing). RC filters 100Ohm/100nF did not work. Traces are ~50cm long.
I’m currently struggling with proper EMI filtering for the low voltage control circuit that is responsible for switching on/off high voltage capacitors using relays.
I realize that the low level part of the circuit has a bunch of design flaws (e.g. the logic signal between uC and shift-reg could’ve been arranged into a differential pair). But currently I’m trying to figure out a way to modify the circuit with as little PCB modifications as possible.
Power circuit is operating on fairly high voltage and current, but I don’t care about the quality of power of this circuit, moreover I cannot modify it.
The only issue I have to deal with looks like this (the description will follow):
Green signal represents EN or CLR; it is a CMOS 3.3V open-drain pin. When voltage falls below certain treshold (I guess 1.8V) it is no longer high, therefore the shift-reg resets. It cannot reset.
2 Asked on December 5, 2020 by mahmoud-maarouf
0 Asked on December 5, 2020
2 Asked on December 4, 2020 by sizu-taylorventuresllc
1 Asked on December 4, 2020 by esilik
0 Asked on December 3, 2020 by crj11
1 Asked on December 2, 2020 by vladimir-martynenko
0 Asked on December 2, 2020 by beatriceuk
1 Asked on December 2, 2020
1 Asked on December 2, 2020 by nalostta
3 Asked on December 2, 2020 by ryantuck
0 Asked on December 2, 2020 by sahithi
1 Asked on December 1, 2020 by diego-colombo
0 Asked on December 1, 2020
1 Asked on November 30, 2020 by bunyamin-tamar
3 Asked on November 29, 2020 by pooya13
1 Asked on November 29, 2020 by digitalnewbie
Get help from others!