My customer tested the ISO7641FM isolation voltage, by applying short-time(1.2/50 us) peak voltage(6000V) pulse between isolation barrier both sides. 4pcs were found damanged and only 2pcs passed the test. Below is test method(each side pins are all shorted) and applied voltage pulse. ISO7641 spec can sustain 6000V peak for 1minutes. So please check what's reason. Thanks.
Please find below. Actually customer do such test from 3KV to 4KV, 5KV, 5.5KV and 6KV. ISO7641 can survive till 5.5KV, as below left waveform. But when do 6KV test, the device broken and voltge waveform like below right(maybe the scope cannot capture the peak waveform, so just show 3KV and down). Do you think this is related to application issue or quality issue?
1. Could you please share more details about the kind of pulse that customer had applied?
2. Do you know how many pulses were applied to each sample? =>One test just use one pulse. Will repeat three times for each voltage level;
3. Do you know if both positive and negative pulses were applied? If yes, how many?=> Only use positive pulse. One pulse per time;
4. Do you know what was the fail signature observed on ISO7641FM? Did the impedance across barrier go down?=>The device/chip surface broken(raised);
