LMR36015-Q1: VOUT biased externally during VIN=0V

Hi:

for 3.3V on Vo, the Vin votlage will be lower than 3V, which will make the device can't work because it is in UVLO statues.

the PG can output low if Vin higher than 2V, our spec of PG indicated the Minimum input voltage for proper Power-Good function is 2V.

Thanks

Hi,

UVLO means Vcc-UVLO, correct? 

If Vcc is UVLO, then what does PG indicate?

If vout is externally biased to 3.3V which is within target range, PG will go High?

Or if Vcc is UVLO, then PG always pull output Low?

regards,

Hi

Yes, VCC UVLO.  

for PG statues, If EN is pulled low, the flag output is also forced low. With EN low, power good remains valid as long as the input voltage is ≥ 2 V (typical).

Thanks

Hi,

In my schematic, EN is connected to VIN, so it should be powered from Vout=3.3V - diode drop, then EN might be ON?

How does PG work when EN = ON?

Regardless of EN status, if VCC is in UVLO, PG = Low? (given VIN>2V)

regards,

Hi Tsuji:

I will double check it, I think PG= low,

let me see my EVM then reply to your later.

Thanks