Manufacturers Part #: UC2879DW
Description: Resonant Controllers 100mA 300kHz 20-Pin Manufacturing
Lot: 8278470M L8
Date Code: 1809
The test spikes the input supply above a threshold for a duration of 50ms to test that the converter which is controlled by U4 is disabled (Note that the maximum time we can run the converter with the spiked input is 50ms). The converter is disabled by grounding U4 pin 6 (Soft Start) and during the spike test the output signal is monitored to confirm the disable has occurred. A typical disable time is within 25ms, on the failing modules this is around 48ms and therefore only just disabling within the 50ms. We have never seen this variation before, is this level of variation in spec for the parts?
