[time-nuts] Diodes as temperature sensors

Chris Albertson albertson.chris at gmail.com
Sun Jul 20 23:18:19 EDT 2014

On Sun, Jul 20, 2014 at 7:07 PM, Al Wolfe <alw.k9si at gmail.com> wrote:

> Seems like there are IC's that contain two diodes, one as a sensor and one
> as a heater. Part numbers escape me now.

You might mean the TMP36 family of sensors.  They use diodes and must be
the most common sensor out there.   They are cheap and ultra-easy to use.
 But when I tried to use one to measure an FE5680 Rubidium oscillator I got
a LOT of noise.  I had to take ten or more reading and average them.   Then
I use shielded cable and place an RC filter near the sensor with only
slight improvement.   Likely I'm still making some kind of design error.
But I moved on to one with a digital I2C output and it worked better.    I
was trying to moderate the fan speed to keep the Rb at constant
temperature.  The fan controller works well enough now.

Here is a really good write up from the place I bought mine from


Chris Albertson
Redondo Beach, California

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