DS75 Digital Thermometer and Thermostat General Description Features The DS75 digital thermometer and thermostat provides 9, Temperature Measurements Require No External 10, 11, or 12-bit digital temperature readings over a -55C to Components +125C range with 2C accuracy over a -25C to +100C Measures Temperatures from -55C to +125C range. At power-up, the DS75 defaults to 9-bit resolution (-67F to +257F) for software compatibility with the LM75. Communication 2C Accuracy Over a -25C to +100C Range with the DS75 is achieved via a simple 2wire serial inter- face. Three address pins allow up to eight DS75 devices Thermometer Resolution is User-Configurable from Nine (Default) to 12 Bits (0.5C to 0.0625C to operate on the same 2-wire bus, which greatly simplifies distributed temperature sensing applications. Resolution) The DS75 thermostat has a dedicated opendrain output 9-Bit Conversion Time is 150ms (Max) (O.S.) and programmable fault tolerance, which allows the Thermostatic Settings are User-Definable user to define the number of consecutive error conditions Data is Read/Written Via 2-Wire Serial that must occur before O.S is activated. There are two (Interface (SDA and SCL Pins) thermostatic operating modes that control thermostat oper- Multidrop Capability Simplifies Distributed ation based on userdefined trip-points (T and T ). OS HYST Temperature-Sensing Applications A block diagram of the DS75 is shown in Figure 1 and Wide Power-Supply Range (+2.7V to +5.5V). detailed pin descriptions are given in Table 2. Pin/software Compatible with the LM75 Available in 8-Pin MAX and SO Packages and as a Pin Configuration 1.5mm x 1.3mm Flip Chip. See Table 1 for Ordering TOP VIEW Information + Applications Include Personal Computers, Cellular SDA 1 8 V DD Base Stations, Office Equipment, or Any Thermally Sensitive System SCL 2 7 A 0 DS75 O.S. 3 6 A1 Pin Description SDA Open-Drain Data I/O GND 4 5 A 2 SCL Clock Input DS75S+ (8-Pin SO 150mil) GND Ground O.S. Open-Drain Thermostat Output + SDA 1 8 V DD A Address Input 0 A Address Input 1 SCL 2 7 A0 DS75 A Address Input 2 V Power Supply O.S. 3 6 A DD 1 GND 4 5 A 2 DS75U+ (MAX) 19-7848 Rev 1 2/08DS75 Digital Thermometer and Thermostat Table 1. Ordering Information ORDERING PACKAGE DESCRIPTION NUMBER MARKING DS75S+ DS75 (see note) DS75 in Lead-Free 150mil 8-Pin SO DS75S+T&R DS75 (see note) DS75 in Lead-Free 150mil 8-Pin SO, 2500-Piece Tape-and-Reel DS75U+ DS75 (see note) DS75 in Lead-Free 8-Pin MAX DS75U+T&R DS75 (see note) DS75 in Lead-Free 8-Pin MAX, 3000-Piece Tape-and-Reel DS75S DS75 DS75 in 150mil 8-Pin SO DS75S/T&R DS75 DS75 in 150mil 8-Pin SO, 2500-Piece Tape-and-Reel DS75U DS75 DS75 in 8-Pin MAX DS75U/T&R DS75 DS75 in 8-Pin MAX, 3000-Piece Tape-and-Reel DS75X/T&R DS75 DS75 Flip Chip, 10,000-Piece Tape-and-Reel Note: A + symbol will also be marked on the package near the Pin 1 indicator Table 2. Detailed Pin Description PIN SYMBOL DESCRIPTION 1 SDA Data input/output pin for 2-wire serial communication port. Open drain. 2 SCL Clock input pin for 2-wire serial communication port. 3 O.S. Thermostat output. Open drain. 4 GND Ground pin. 5 A Address input pin. 2 6 A Address input pin. 1 7 A Address input pin. 0 8 V Supply Voltage. +2.7V to +5.5V supply pin. DD Maxim Integrated 2 www.maximintegrated.com