Hello,
I have a rather simple circuit that became quite a puzzle when printed on a PCB and after spending lot's of time to figure out what is wrong I really got obsessed and I'd like to ask for some help to figure it out.
Here is my circuit, is an LTC1017I comparator that takes 2 input voltages and produces an EN signal of 5V if both voltages are disconnected or less than 5V. Vps, Vsw and Vbat are all on 16.8V.
When tested on bread board the circuit works as expected!
After breadboard testing, I made the following PCB but I keep getting a 5V output on EN pin. Also, don't mind the components on the right side, I did not solder them during the troubleshooting, but if you are really curious about the whole board I can share the project with you.
While testing I tried cutting the EN trace between the two leads of U1 (OUTA and OUTB signals of the IC) and also disconnected R4 and measurements show that OUTA is always at 5V even when Vps value is at 16.8V while OUTB performs as expected.
Further, some extra info, there are no shorts with 5V plane to EN pin, continuity test verifies that all components are connected correctly without shorts and get the right voltages.
If you have any ideas on what might be the problem or something that I could test please let me know!
Thanks,
Christos
I have a rather simple circuit that became quite a puzzle when printed on a PCB and after spending lot's of time to figure out what is wrong I really got obsessed and I'd like to ask for some help to figure it out.
Here is my circuit, is an LTC1017I comparator that takes 2 input voltages and produces an EN signal of 5V if both voltages are disconnected or less than 5V. Vps, Vsw and Vbat are all on 16.8V.
When tested on bread board the circuit works as expected!
After breadboard testing, I made the following PCB but I keep getting a 5V output on EN pin. Also, don't mind the components on the right side, I did not solder them during the troubleshooting, but if you are really curious about the whole board I can share the project with you.
While testing I tried cutting the EN trace between the two leads of U1 (OUTA and OUTB signals of the IC) and also disconnected R4 and measurements show that OUTA is always at 5V even when Vps value is at 16.8V while OUTB performs as expected.
Further, some extra info, there are no shorts with 5V plane to EN pin, continuity test verifies that all components are connected correctly without shorts and get the right voltages.
If you have any ideas on what might be the problem or something that I could test please let me know!
Thanks,
Christos