LM5146: LM5146 VCC is only 0.6V after set En pin=2.7V

W SM

Part Number: LM5146

Tool/software:

In My new design with LM5146, Its Pin14 VCC is only 0.6V after power up and En Pin is set 2.7V,VIN=12V。

Is connecting Pin9，Pin16（NC Pin）to PGDN a possible reason?

+1 Taru Kapoor 4 months ago

Hi,

I don't think connecting the NC pins to PGND will lead to this. In fact, tying these pins to PGND is a good idea to improve thermals of your design.

Thanks,

Best Regards,

Taru

+1 W SM 4 months ago in reply to Taru Kapoor

+1 W SM 4 months ago in reply to W SM

Thank for you reply.

I found the cause,is that the diodes(DSS24) from Vout to VCC was soldered backwards.

+1 Taru Kapoor 4 months ago in reply to W SM

Good to know that your problem is solved!

Please close the thread if there are no further questions.

Thanks,

Best Regards,

Taru

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