Lt3753 and EMC noise effecting on OC pin

Hi Ali,

If you already verified that there is no actual overcurrent event that triggers the OC then you can try to ground the OC pin to make sure that it is the OC fault that causes your output to go to zero.

You can try adding a filter on the current sense signal similar to the standard demo board DC2306A (R10, R11, C7): https://www.analog.com/media/en/technical-documentation/eval-board-schematic/DC2306A-4-SCH.PDF

Looking at the same schematic, you can also increase the OC threshold by adding a resistor divider (R3 and R4).

Regards,

Hi Ali,

If you already verified that there is no actual overcurrent event that triggers the OC then you can try to ground the OC pin to make sure that it is the OC fault that causes your output to go to zero.

You can try adding a filter on the current sense signal similar to the standard demo board DC2306A (R10, R11, C7): https://www.analog.com/media/en/technical-documentation/eval-board-schematic/DC2306A-4-SCH.PDF

Looking at the same schematic, you can also increase the OC threshold by adding a resistor divider (R3 and R4).

Regards,

• Hello. Thank you for your help. I have already grounded the oc pin of the chip.But the problem was not solved. I have also added a filter on the current sense signal similar DC2306A demo board. But the problem remains. The problem will only be solved if the R10 and R11 resistors from 100 ohms are converted to 2.2K ohm. But in this case, the protection against short circuit and over current is canceled. I worked with a lot of chips from ANALOGE DEVICE co. Such as AD1071, AD1074, LTC3765 / 3766, etc. But this problem only occurs in LT3753 and LT3752 chips. I think this problem arises due to the sensitivity of the OC pin and coming out of the pack. I thoroughly investigated the demo board(DC2306A),And I designed my PCB exactly according to DC2306A,But the problem still remains. The Images related to the filter section in the schematic, and the output waveform due to EMC noise are send.

I unfortunately can't send images for you.