MAX6675 Thermocouple Chip.....Alive or Dead?

Scott4

I had a voltage event on my PCB and got 12V on the 5V line. It let the smoke out of an ADC on the same circuit·but I have 2 MAX6675 chips ($14 each) that show no outward sign of damage. Attached are some files that show my setup. The response from the Debug statement is "0" so I still don't know if the chips are·dead or if I may be doing something wrong with the setup or program.

Anyone have experience with these? -Scott

kf4ixm

I know from working with alot of max and ds chips that they are not very forgiving on the vcc voltage, anything above 7-8vdc usually makes them go into 'r.i.p' mode. your circuit and code looks fine as far as i can tell.

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I'm just 7*10²⁷ atoms floating through time and space in close formation. -KF4IXM

Scott4

I replaced the chips. Now the Debug statement returns 32764.·Being clueless, I dusted off·my Parallax Logic analyzer and got the attached result.·The chip seemed to respond·but not what·I would expect. Is there any condition that this chip would send back this data or have I burned up the chip soldering it in? -Scott

Franklin

Could you attach your code?

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- Stephen

Scott4

Still using the same code as in first post. -Scott

Franklin

Well no wonder it does not work. That code won't even compile in my stamp editor. How are you getting debug info?

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- Stephen