I am using a tmp36 temperature sensor to measure temperature (with an attiny 85), when I put 5V across the GND and Vs pins of the to92 model the Vout is not 0 (I can't remember the exact value now but perhaps 0.7 or similar).

I have been trying to make a surface mount board and the Vout value using the SOIC version of the tmp36 temperature sensor is only a few mV (or sometimes 0). I thought maybe I had killed the chips when soldering them but I just tried one before it was soldered and it is giving Vout of 0V. I also checked all the other pins in case I had the wrong Vout pin and they were all 0. Is there something obvious I am doing wrong, or could I have gotten fake chips? (bought from two different suppliers though)... will go and check a few more now.


  • 3
    \$\begingroup\$ Do you have the /SHUTDOWN line pulled high? The TO92 version doesn’t have this pin. \$\endgroup\$ Feb 15, 2018 at 11:51
  • \$\begingroup\$ Also, show your layout. \$\endgroup\$
    – Wesley Lee
    Feb 15, 2018 at 11:52
  • \$\begingroup\$ No, I haven't connected anything to shutdown. The only connections I have are Vs = 5v, GND = 0V and then using a multimeter to measure between GND and Vout \$\endgroup\$
    – Shara
    Feb 15, 2018 at 12:11
  • \$\begingroup\$ do I need to pull the shutdown line high? .... \$\endgroup\$
    – Shara
    Feb 15, 2018 at 12:12
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    \$\begingroup\$ @RussellBorogove thanks!!! I checked the datasheet which said to pull the shutdown line high and now it's reading 0.7V. Thanks very much. If you want to add this as an answer I will accept it. \$\endgroup\$
    – Shara
    Feb 15, 2018 at 12:17

1 Answer 1


The SOIC and SOT-23 packages for this part offer a “shutdown” state in which it consumes almost no current. The /SHUTDOWN line controls this mode. For normal operation, /SHUTDOWN must be held high — tying it to the positive voltage supply should work.

The TO-92 version of the part doesn’t have this signal; it is always running as long as it’s powered.

Many modern parts have features like this as power management for small portable devices has become a priority.


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