I have purchased several of these TMP36/37 units from 4 different vendors, and all of them behaved the same terrible way. The output readings are inconsistent, unstable, jump all over the place, and the device is highly susceptible to electromagnetic radiation interference. The MCP9701A is an infinitely better, more stable device. Here is some info on the MCP9701A:
https://github.com/Joe0x7F/MCP9701A
People should stop making excuses for the TMP36 device. It's terrible and gives analog devices an undeserved bad name.
Adafruit should switch to the MCP9701A instead.
In 2022, the TMP36 is terrible.
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- adafruit2
- Posts: 22111
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Re: In 2022, the TMP36 is terrible.
the TMP36 is sorta like the LM741, its not really used often and its for beginners learning about ADC. that said, try adding a 20K pulldown - that may help.
http://www.doctormonk.com/2015/02/accur ... -from.html
http://www.doctormonk.com/2015/02/accur ... -from.html
- Joe0x7F
- Posts: 5
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Re: In 2022, the TMP36 is terrible.
I've already tried all that, multiple times over multiple units. Simon is wrong in this case for 2022.
If you try the MCP9701A beside the TMP36, then you will immediately see how the TMP36 is supposed to behave.
If you try the MCP9701A beside the TMP36, then you will immediately see how the TMP36 is supposed to behave.
- westfw
- Posts: 2005
- Joined: Fri Apr 27, 2007 1:01 pm
Re: In 2022, the TMP36 is terrible.
Maybe someday the MCP9701A will actually be "in stock" at most major distributors again...
(One wonders if the poorly performing TMP36 chips are "real", or perhaps "clones.")
(One wonders if the poorly performing TMP36 chips are "real", or perhaps "clones.")
- Joe0x7F
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Re: In 2022, the TMP36 is terrible.
Yes, if I had known that was going to happen I would have worked on characterizing a different analog sensor.westfw wrote:Maybe someday the MCP9701A will actually be "in stock" at most major distributors again...
I was shocked at what I was seeing. Never seen anything that bad and so widely used. Rechecked many times but same results.westfw wrote:(One wonders if the poorly performing TMP36 chips are "real", or perhaps "clones.")
- Joe0x7F
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Re: In 2022, the TMP36 is terrible.
You can take a look at the LMT87LPG. It's stable also.westfw wrote:Maybe someday the MCP9701A will actually be "in stock" at most major distributors again...
https://github.com/Joe0x7F/LMT87
- Joe0x7F
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Re: In 2022, the TMP36 is terrible.
It looks like there are some MCP9701A-E/TO currently available from Arrow.com:
https://www.arrow.com/en/products/mcp97 ... 01A-E%2FTO
I'd also take a look at the LMT87LPG to see if it fits your situation better.
https://github.com/Joe0x7F/LMT87/
https://www.arrow.com/en/products/mcp97 ... 01A-E%2FTO
I'd also take a look at the LMT87LPG to see if it fits your situation better.
https://github.com/Joe0x7F/LMT87/
- jordancram
- Posts: 9
- Joined: Sat Sep 10, 2022 10:19 am
Re: In 2022, the TMP36 is terrible.
Before seeing this post...I bought 10 of these from Adafruit to obtain temperature on the board since the unit will be in an enclosed (waterproof) casing.
I tried the 20k and 47k resistor approach (gnd to Vout) and it didn't stabilize the readings. My multimeter is reading between 50 and 300 mV. This is below the expected voltage in the Adafruit intro. When the radio frequency module turns on, the reading reduces a lot.
I'm just checking in on this post to see if there are any final ideas for the TMP36 other than the rubbish bin. Or, any alternates.
I tried the 20k and 47k resistor approach (gnd to Vout) and it didn't stabilize the readings. My multimeter is reading between 50 and 300 mV. This is below the expected voltage in the Adafruit intro. When the radio frequency module turns on, the reading reduces a lot.
I'm just checking in on this post to see if there are any final ideas for the TMP36 other than the rubbish bin. Or, any alternates.
- adafruit2
- Posts: 22111
- Joined: Fri Mar 11, 2005 7:36 pm
Re: In 2022, the TMP36 is terrible.
make sure your aref is stable, i bet the power supply is dipping!
Please be positive and constructive with your questions and comments.