Dear Expert
Test conditions: input voltage 230V, output 12V with half load 2.915A, abnormal because the power supply current equalizing IBUS voltage is high, the specification is 2.9-3.3V, the actual test is bad 3.41-3.43V, The failure rate is about 81/900 =9%
Sch:
Below is test input and output wave form
Figure 1 shows the PIN1 waveforms output by LM2904, PIN5 and PIN6 input by LM2904, and PIN7 output by LM2904
Figure 2. VBus: 3.495 V
Figure 3 shows the pressure difference of 29.8mV between PIN2 and PIN3
