We have used a PTH08T250W in our design.
During verification, we found that when we measure the PTH08T250W GND Pin (8,9 and 12,13) against the ground at the 12V input, there is significant ground noise generated on Pin(8,9) and Pin(12,13). On Pin(8,9), p-to-p is about 700mv while pin(12,13) is about 300mv. Please see the pic below. The noise is still there even after we shut down the PTH08T250W by pull down the track pin. Since this noise is so significant, it propagates through ground plane and can be directly measured on every other power rail.
Please comment if this is normal and advise how to reduce it. Thank you very much
