Digital Thermometer and Thermostat with Extended Addressing

This low-voltage (1.7V to 3.7V) digital thermometer and thermostat provides 9, 10, 11, or 12-bit digital temperature readings over a -55°C to +125°C range with ±2°C accuracy over a -25°C to +100°C range. At power-up, the DS75LX defaults to 9-bit resolution for software compatibility with the LM75. Communication with the DS75LX is achieved through a simple 2-wire serial interface. Three tri-state address pins allow up to 27 DS75LX devices to operate on the same 2-wire bus, which greatly simplifies distributed temperature-sensing applications.

The DS75LX thermostat has a dedicated open-drain output (O.S.) and programmable fault tolerance, which allow the user to define the number of consecutive error conditions that must occur before O.S. is activated. There are two thermostatic operating modes that control thermostat operation based on user-defined trip-points (TOS and THYST).

Applications

* Any Thermally Sensitive System * Cellular Base Stations * Servers * Telecom Switches and Routers

* 1.7V to 3.7V Operating Range

* Tri-State Address Pins Allow Up to 27 Unique Bus Addresses

* Temperature Measurements Require No External Components

* Measures Temperatures from -55°C to +125°C (-67°F to +257°F)

* ±2°C Accuracy from -25°C to +100°C

* Thermometer Resolution Is User-Configurable from 9 (Default) to 12 Bits (0.5°C to 0.0625°C Resolution)

* 9-Bit Conversion Time is 25ms (max)

* Thermostatic Settings are User-Definable

* Data is Read/Written Through 2-Wire Serial Interface (SDA and SCL Pins)

* Data Lines Filtered Internally for Noise Immunity (50ns Deglitch)

* Bus Timeout Feature Prevents Lockup Problems on 2-Wire Interface

* Multidrop Capability Simplifies Distributed Temperature-Sensing Applications

* Pin/Software Compatible with the LM75

* Available in 8-Pin µSOP (µMAX®) and SO Packages