Other Parts Discussed in Thread: TPS386000
Hello,
I start this new thread because the last was locked (after only 1 month ?).
The initial thread is on this link:
At the end, we think the problem comes from the input EN behavior
1) At the start, the EN input is directly link via resistor bridge to the input voltage (24V). But when the input voltage was noised, the chip not start and was blocked, the output voltage was 1 or 2V.
2) We link EN from an TPS386000. By this, the problem comes when input voltage grow up very slowly. In fact, when the input voltage overpass the input threshold of the TPS386000 (17V), the EN input was enabled. The LM5160 start. But its start lead to load the input and generate some minor noise, but this was sufficient if the input voltage nt grow enought, to goes under the TPS386000 threshold hysteresis. THen its output lock again the EN Input, and after few ms enable again. (If the input voltage grow up fast, there is no problem).
Then we can conclued the LM5160 has a strange behavior and will be blocked if EN input is not stable and evoluate too fast. I reproduced a simplified chronograme:
From the point 2 observation, we validate this conclusion by only place a manual switch on the input EN. We easily reproduce the problem when we make move this switch fast (< 100ms). THis could be easily reproduced on your side.
Bellow the schematic we finaly design to correct the problem
What is your opinion on my analys? Is possible you reproduce this problem on your side?
Regards and thank for your support.