AnsweredAssumed Answered

LTC4633 Issue at start up

Question asked by Lorenzo_m on Jul 5, 2018

Goodmorning, 

we have some problems with this chip: it works properly when it is supplied with a 28V but when we powered it with 9-10V, it doesn't work as expected: before starting it waits for 9 seconds and then start to charge the mosftet creating a ramp in the output. I attached some pictures about the oscilloscope input and output at 10V. The circuit used is attached in the schematic, except for the mosfet that is a little bit different (in real circuit IXFB210N30P3) which has a typical VTH of 2,5V. The resistances values are extrapoleted from the evualation board DC2150A which is expected to work from 9V. 

Thanks in advance for any help.

Best Regards

Lorenzo

Attachments

Outcomes