> More details please....
>
> *Circuit is very sensitive to my hand*
> What happens when you move your hand nearby ?
> Perhaps the transistor is

usually fan speeds up.

Transistor is a small n-fet, but I tried npn bipolar before with same resul=
ts.

> How are you varying the temperature ?
> How are you monitoring the temperature ?

I am heating up one pad (not connected) close to the IC on a board,
with soldering iron. Then the fan cools it down.
Sometimes "overheat" led turn on as expected, but usually not. "fault"
led does not ever light on. It is good and connected properly, I
checked :)

> how are you monitoring /FAULT ?

same as on demo board, just a small led with 1k resistor to +5v. Fault
led connected same way.

> How are you driving /SHDN ?  It may be wise to put a pullup resistor to V=
dd on this pin.

It did not work at all without that.

>
> Do you have a DMM ?
> If so, check the voltage going to the TC652.
>     Datasheet says chip can accept 2.8 to 5.5V.

it is 5V, I even tried another source and even local 5V regulator fed from =
12V.




I was asking more like to find out if anybody else has real experience
wit these chips. They do not seem to be very popular, probably there
is a reason for that.
This should not be a bad chip, since I tried another one too. Sure,
they are from the same run, as were ordered together.
It could be done using a pic, but implementing all of those nice
features would take a lot of time (for me)

--
KPL
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