Part Number:LM5069
Hi,
I'm using the LM5069 with a PSMN3R8-100BS as the MOSN Switch to
have the Hot-Swap function, and the soft-start when I enable it via a little MOS (µC controlled) on the UVLO Pin,
as preconised in the LM5069 datasheet.
In my desing the PGD pin is pulled high with a 47K resistor going to the VOUT (OUT of the LM5069, a 48V bus).
After several tests and modifications, for some reasons (Rsense modification without modifying RPWR),
the PSMN3R8-100BS died in a Drain-Source short circuit ; but without damage for downstream circuitry.
As the MOS in short circuit :
- when the µC "shutdowns" (via the little MOS on the UVLO pin) the LM5069 and the tension (48V) it commands,
the 48V bus does not fall effectively. - but the PGD signal goes down, which is (as presented in the datasheet being just a comparator between VIN (SENSE) and VOUT)
impossible and a false information as the MOS in short circuit, the VOUT could not be 2.5V under SENSE (VIN)...
So I want to know if this is :
- A normal behaviour (I can misunderstand the datasheet)
- Not mentionned in the datasheet, but in reality the PGD pin is a convolution of the comporator (SENSE-VOUT) output and the UVLO PIN
(maybe this is not wanted) - My LM5069 has been damaged
- ...
Best Regards,
Brice