1

I've been learning Arduino and playing with the TMP36 sensor, trying to read temperature of my room. To do that I've assembled a super-easy scheme just to read the values to Serial monitor, something very similar to the following pic. TMP36 Arduino Scheme

The problem is that silly me inserted the sensor facing the wrong way (not how it is depicted in the picture above but the other way around) and the temperature of the sensor went to 200+C. The actual component temperature also spiked since and I actually burnt my fingers when I touched it. I'm struggling to understand why this happened. Now obviously the problem is caused by the fact that power went through the pin that was supposed to be ground, however why did the temperature spike? Does this have something to do with the internal structure of the TMP36 sensor or is it something fundamental to this process that I don't understand?

enter image description here

Abgar Kebar
  • 11
  • 1
  • It's likely there was some breakdown somewhere, leading to significant current flow through the device. – Hearth Jun 10 '20 at 21:16
  • @Hearth I should also note that the sensor worked after it was inserted correctly, can this fact rule out breakdown? Or is it possible for the device to work even if this happened? – Abgar Kebar Jun 10 '20 at 21:18
  • Breakdown doesn't necessarily destroy the device. Zener diodes for instance are only intended to operate under breakdown conditions. When a device isn't designed to survive breakdown, though, it's very possible that it won't. I wouldn't risk it, since this device got hotter than it's rated to; the datasheet lists the absolute maximum temperature as 160°C, and you were well above that. – Hearth Jun 10 '20 at 21:24
  • If you interpreted the *analog voltage out* while inserted backwards as the actual temperature, that's likely wrong. Burnt finger suggests it did get very hot - but how hot ? You don't really know. – glen_geek Jun 10 '20 at 21:32
  • Possible duplicate of https://electronics.stackexchange.com/questions/97738/what-exactly-fries-the-chip-when-you-invert-power-supply – Spehro Pefhany Jun 10 '20 at 21:47

0 Answers0