I wonder if it's possible to start up a DGD05473 from 2.7-3.3V until a higher voltage is available in the system. The datasheet says it will lockout if Vcc is below 3.3V. Is there some trick to work around the lockout or am I out of luck?

 

Since I have no clue as to what a DGD05473 actually is, what I can tell you is that the short answer is NO! Various circuits have minimum voltages and below that minimum voltage nothing happens, at least nothing useful.

 

Hello,

@MisterBill2 , this seems to be the device:
https://www.diodes.com/part/view/DGD05473/

Bertus

 

Since I have no clue as to what a DGD05473 actually is, what I can tell you is that the short answer is NO! Various circuits have minimum voltages and below that minimum voltage nothing happens, at least nothing useful.

Yes, I've added a charge pump to boost the voltage above the undervoltage lockout threshold for the startup period. The simulations seem to run fine now. I wish they would lower the threshold to 3V or below (a discharged 3.7V lithium-ion battery).

 

@MisterBill2 , this seems to be the device:
https://www.diodes.com/part/view/DGD05473/

Yes, it's that part. It seems to be quite popular. Used in Teslas, for instance: https://www.chargerlab.com/teardown-of-tesla-model-y-15w-wireless-charging-module-2/

 

There are valid reasons for having a low-voltage lockout, and the one I see as most obvious is the probability of unwanted random actions of the circuit at lower voltages.