Thermal Sensors on I2C
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I've been working on a PCB layout and made room for an additional I2C chip.
The PCB has all the EEProm expansion it would ever need and a RTC good for 10 years.

So I'm looking for something in an I2C chip packaged SOIC 8pin (208mil or 150mil) to take advantage of the space. A device in the same pinout as the standard EEProm that would add a little extra capability to the design.

After scanning every I2C company I know, a thermal sensor appears to be the best pick. As I've mentioned before, our product has to deal with very cold temperatures due to high altitudes. Even though we are in a sealed metal case, adding internal monitoring of temperature would allow me to modify our power profile to regulate the internal temperature and thereby decrease our minimum temperature specification or at least increase it beyond its published point.

I've been looking at thermal sensors and surprisingly, a company 3 kilometers away appears to have the best product.

Dallas Semiconductor's DS1621 & DS1624:

http://www.dalsemi.com/datasheets/pdfs/1621.pdf

are both I2C, accurate to 0.5C and per ApNote 105 below, capable of higher resolution with a previously unpublished register access:

http://www.dalsemi.com/datasheets/pdfs/app105.pdf

I don't require that type of accuracy, but I want it in the product because its the best for the circuit opening I have. It will allow us to experiment.

The only thing not perfect about this chip is DalSemi's defiant I2C pinout. What's the deal?! Is there a licensing restriction on I2C pinouts?

I guess I'll just add the DS162x pinout to the free I2C pad and give up the ability to place another EEProm there. I suppose DalSemi has a memory EEProm I could always place there.

Anyone know of another I2C standard pinout thermometer chip with 0.5C accuracy and high resolution?

-Jay C. Box