What's the hi-side current sense chip du jour?

Yeah, ok, I have done that on fully patient-isolated med devices but it's hard to do when you only have the real estate of a penny available.

I could, but this time there just ain't no space for all the resistors that go with that.

Then there's "Fudge's Factor"; the right answer divided by your answer.

Harborfreight contactless thermometer hacked and read out into a uC, which then thinks about the situation, shuts down the box, activates the sprinkler system and sends a text message to the fire department if further rising readings indicate an exothermal behavior :-)

Phil, you just described the California state budget system :-))

That actually works but requires analog glue. In this case I can't hog parts of the uC for stuff like this plus it's too slow.

Thanks, I'll have to check. I only know some that watch the FET current but even then there is way too much tolerance on the threshold.

That would be a problem in this case.

Newark stocks the LT6106CS5.ABS Max 44VDC

Its a little pricey like most of LT's stuff but it has integrated current liminting resistors and clamping diodes.

Their only other choice is to not live. Sad, isn't it?

I take it you have, as usual, no room and no budget ?:-)

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

And Cole's Law: thinly sliced cabbage. :-)

Cheers, James Arthur

No room for an SC70-6 and three resistors? You *are* pinched! Better get out your wallet.

Cheers, James Arthur

Joerg seems to have budget this time--normally he'd do this with a hair-pin and some adhesive tape!

Grins, James Arthur

Just use some #40 for a fuse ?:-)

...Jim Thompson

Thanks, it's actually not that expensive, around a Dollar in qties. A bit unorthodox though, hard to 2nd source. If anyone else is interested:

Might not work in my case though because it derives its VCC from the load rail and that could, in the case of a hard short, reside at a few hundred mV and still draw a ton of current.

Room no, budget yes. Within limits, as usual :-)

IOW I can't spend several Dollars per hi-side sense. $1 would be ok. What a relief, usually I'd have 5-10c here ...

Especially since we are training a guide dog over the weekend and his name is McGyver (seriously).

I prefer Cuervo's law: A margarita heavy on the Jose Cuervo can fix just about anything.

Well, I'll just find a SOT23-5 device in the Dollar-range with voltage output and then I am home. I just need to pick one that's popular so it won't go lalaland in a few years, hence my post :-)

It's strange that buck PWM chips typically don't offer this function. At least not new ones that can go up to a MHz.

We named The Brat's dog "Donner" because she'll eat anything.

John