I am working with Logic Gate Output Optocoupler. I have tried removing 15pF capacitor but it didn't made any difference.
On output port it is generating noise
Any help would be appreciated..!
Thanks in advance
\$\begingroup\$
\$\endgroup\$
Add a comment
|
1 Answer
\$\begingroup\$
\$\endgroup\$
4
Your schematic is barely legible, but it appears that you have a resistor (R8?) in series with VDD of a CMOS logic power rail. That shouldn't be there and will cause the voltage to drop depending on the load on VO.
-
\$\begingroup\$ Currently, it doesn't have any load and only the oscilloscope is connected. I am trying to change it to 0E and see. Thanks for the help.. I have updated image as well \$\endgroup\$Abhishek Parikh– Abhishek Parikh2021-07-28 10:43:18 +00:00Commented Jul 28, 2021 at 10:43
-
\$\begingroup\$ That bounce in the output is weird. I don't have an explanation for that. \$\endgroup\$Transistor– Transistor2021-07-28 10:53:34 +00:00Commented Jul 28, 2021 at 10:53
-
4\$\begingroup\$ The 220 ohm resistor is still invalid on a logic power supply, and the 1nF bypass capacitor is two orders of magnitude too small, and the 15pF capacitor must be removed as it just resembles load capacitance that was presented to the opto output under the test conditions. \$\endgroup\$Justme– Justme2021-07-28 11:20:04 +00:00Commented Jul 28, 2021 at 11:20
-
1\$\begingroup\$ We have replaced R7 by 330E and R8 by 0E and this is working perfectly fine \$\endgroup\$Abhishek Parikh– Abhishek Parikh2021-07-28 12:32:10 +00:00Commented Jul 28, 2021 at 12:32