Other Parts Discussed in Thread: TPS1H000-Q1, TPS1H200A-Q1
Hi Team,
Good day.
I would like to seek your assistance for our customer's query as follows:
I am using the TPS1H100A on a new design. During testing I've come across behaviour in the current limit which I didn't realise when designing in, and can't understand why the IC is designed like this.
When the current limit is reached, it current limits, which means there is more voltage over the FET, and so it heats up more. Then, once a thermal delta limit is reached the part turns off, and back on, as a square wave re-trying. All OK so far.
But then (as in Figure 37 of the datasheet) once a high temperature limit is reached the part limits to HALF the current, and the datasheet says "the current limit is reduced to Ilim,tsd, or half of the programmable current limit value, to avoid repeated thermal shutdown". However this will only make it worse! It means the load could drop below the original set current limit and still be current limited! The load would have to be reduced drastically or removed and added back, possibly meaning a site visit for a remote piece of equipment. Why not just back off the retry TIME? And manage the temperature that way, so that when the current was below the limit again everything would just work.
1) Am I misunderstanding something?
2) Is there any way to get this part to function as I want (retry & work once back below the original current limit)?
3) If not, do you have any other part recommendations - which don't lock the part into a mode which it won't be able to recover from?
Thank you in advance for the help.
Regards,
Carlo
