DS620 Low-Voltage, 0.5C Accuracy Digital Thermometer and Thermostat www.maxim-ic.com GENERAL DESCRIPTION FEATURES The DS620 digital thermometer and thermostat Low-Voltage Operation: 1.7V to 3.5V provides low-voltage (1.7V V 3.5V) temperature 0.5C Accuracy from 0C to +70C DD measurements with 0.5C accuracy from 0C to Operating Temperature Range: -55C to +125C +70C and an operating temperature range of -55C (-67F to +257F) to +125C. The DS620 communicates over a 2-wire Temperature Measurements Require No digital interface. For distributed-sensing applications, External Components it is multidroppable with three address pins that allow Resolution is User-Selectable to 10-, 11-, 12-, or up to eight DS620s to operate on a single bus. 13-Bits (0.5C, 0.25C, 0.125C, and 0.0625C LSb Weight, Respectively) The DS620 has thermostat functionality with user- Multidroppable defined thresholds stored in EEPROM registers, and Fast (200ms max) Temperature-to-Digital it can be configured for standalone thermostat Conversion Time operation. The programmable output (PO) pin serves Thermostatic Settings are User-Definable and as the thermostat output, and this pin can also be Nonvolatile configured to function as an active-low control for Standalone Thermostat Capability peripheral devices. Data is Read/Written Through a 2-Wire Serial Interface Package: 8-Pin SOP APPLICATIONS Portable Applications ORDERING INFORMATION Low-Voltage Temperature-Sensitive Applications PART TEMP RANGE PIN-PACKAGE Computers/Servers 8 SOP, Test Equipment DS620U -55C to +125C Exposed Pad Medical Instruments 8 SOP Industrial Applications DS620U/T&R -55C to +125C Exposed Pad Tape-and-Reel PIN CONFIGURATION TYPICAL OPERATING CIRCUIT 1.7V to 3.5V 1.7V to 3.5V SDA VDD VDD . SCL A0 SDA SDA PAD PO SCL SCL PO A1 DS620 A0 GND A2 A1 Thermostat A2 HOST GND 8-Pin SOP Package PAD Exposed Pad 1 of 15 041607 DS620 Digital Thermometer and Thermostat PIN DESCRIPTION PIN NAME FUNCTION 1 SDA Data Input/Output Pin for serial communication. Open drain. (No diode connection to V ). DD Clock Input Pin for 2-wire serial communication. 2 SCL Programmable Output Pin. Open drain. (No diode connection to V ). 3 PO DD Ground Pin. 4 GND 5 A2 Address Input Pin. 6 A1 Address Input Pin. Also serves as an input to trigger one-shot conversions during standalone use. 7 A0 Address Input Pin. Supply Voltage Pin. +1.7V to +3.5V power supply pin. 8 V DD PAD. Connect to GND or float. DO NOT CONNECT TO SUPPLY. The exposed pad is the best way to conduct PAD temperature into the package. Connecting PAD to a ground plane can assist in properly measuring the temperature of the circuit board. Figure 1. Block Diagram DS620 Temp. Core Digital Control Bandgap POR ADC Memory Array Configuration Register Conversion Control TH, TL Registers Digital Comparator Address/Command PO Pin PO Decode Control Temperature Register Address Counter Temperature Counter Charge Pump User EEPROM Registers SCL 2-Wire Interface SDA Memory Interface Logic A0 A2 A1 2 of 15