Hi,
I am with Maxim. We make the DS1620. Someone in our technical organization saw your question and replied:
Thank you for your interest in Maxim parts.
The DS1620 is a temp sensor with 3-wire communication. This part reads local temperature (the temperature of the chip), and user can set the high/low alarm temperature. If the temperature exceeds the alarm temperature, the responding trigger pin goes high. More details are in the DS1620 datasheet, and it can be found here:
**broken link removed**
Also there are some DS1620 appnotes that can help you with your design:
**broken link removed**
If you do have any question regarding Maxim parts, feel free to visit Maxim's online Technical Support site. We will be happy to help you with your question.