1-Wire Temperature/Data Logger with 8KB Datalog Memory

The iButton® temperature/data logger (DS2422) combines the core functions of a fully featured data logger in a single chip. It includes a temperature sensor, real-time clock (RTC), memory, 1-Wire® interface, and serial interface for an analog-to-digital converter (ADC), as well as control circuitry for a charge pump. The ADC and the charge pump are peripherals that can be added to build application-specific data loggers. Without an external ADC, the DS2422 functions as a temperature logger only. It measures the temperature and/or reads the ADC at a user-defined rate. Additionally, the DS2422 can store 8192 8-bit readings or 4096 16-bit readings taken at equidistant intervals ranging from 1 second up to 273 hours.

Applications

* Data logging (with an external ADC and charge pump), the DS2422S could be used in many data logging functions, such as pressure monitoring, light sensor monitoring, logging thermocouple temperatures, etc. * Monitoring of refrigeration systems, and environmental or thermal management systems (HVAC). * Temperature-Critical Product Shipping and Storage, such as Fresh Produce, Pharmaceuticals, and Blood Products.

* Automatically Wakes Up, Measures Temperature and/or Reads an External ADC and Stores Values in 8KB of Datalog Memory in 8 or 16-Bit Format

* On-Chip Direct-to-Digital Temperature Converter with 8-Bit (0.5°C) or 11-Bit (0.0625°C) Resolution

* Sampling Rate from 1s up to 273hrs

* Programmable Recording Start Delay After Elapsed Time or Upon a Temperature Alarm Trip Point

* Programmable High and Low Trip Points for Temperature and Data Alarms

* Quick Access to Alarmed Devices Through 1-Wire Conditional Search Function

* 512 Bytes of General-Purpose Memory Plus 64 Bytes of Calibration Memory

* Two-Level Password Protection of all Memory and Configuration Registers

* Unique Factory-Lasered 64-Bit Registration Number Assures Error-Free Device Selection and Absolute Part Identity

* Built-in Multidrop Controller Ensures Compatibility with Other Dallas Semiconductor 1-Wire Net Products

* Directly Connects to a Single Port Pin of a Microprocessor and Communicates at up to 15.4kbps at Standard Speed or up to 125kbps in Overdrive Mode

* -40°C to +85°C Operating Range

* 2.8V to 3.6V Single-Supply Battery Operation

* Low Power (1.2µA Standby, 350µA Active)