The DS1822Z is a digital thermometer with ±2°C accuracy over a -10°C to +85°C range. Data is read out over a 1-Wire serial bus in 2's complement format with 9 to 12 bits of resolution (user-programmable). The DS1822Z offers thermostatic functionality with over-temperature (TH) and under-temperature (TL) user-programmable setpoints stored in on-chip EEPROM. An internal flag is set when the measured temperature is greater than TH or less than TL. If thermostatic operation is not required, the two bytes of EEPROM reserved for TH and TL may be used for general-purpose nonvolatile storage. Each DS1822Z features a unique and unchangeable 64-bit silicon serial number, which serves as the bus address for the sensor. This allows multiple DS1822Z devices to coexist on the same 1-Wire bus. The DS1822Z may be locally powered via a 3.0V to 5.5V supply, or power can be derived from the 1-Wire data line ("parasite power"). The DS1822Z is offered in 3-pin TO-92 (DS1822) and 150mil 8-pin SO (DS1822Z) packages. In addition, the DS1822Z is available in a parasite-power only version, the DS1822-PAR. Also available is the high-precision DS18B20, which provides ±0.5°C accuracy and is software-compatible with the DS1822.
Feature
- Unique 1-Wire? Interface Requires Only One Port Pin for Communications
- Can Be Powered from Data Line
- Power-Supply Range is 3.0V to 5.5V
- Reduced Component Count with Integrated Temperature Sensor and Interface
- Requires No External Components
- Measures temperatures from -55°C to +125°C (-67°F to +257°F)
- ±2.0°C Accuracy from -10°C to +85°C
- Thermometer Resolution is User-Selectable from 9 to 12 Bits
- Converts Temperature to 12-Bit Digital Word in 750ms (max)
- Simplifies Distributed Temperature Sensing with Multidrop Capability
- Each Device Has a Unique 64-Bit Serial Code Stored in an On-Board Device
- Flexible, User-Definable Nonvolatile (NV) Alarm Settings with Alarm Search Command Identifies Devices with Temperatures Outside Programmed Limits
- Software compatible with the DS18B20
- Applications Include Thermostatic Controls, Industrial Systems, Consumer Products, Thermometers, or Any Thermally Sensitive System
Applications
- Fire Alarm Systems
- Hard Disk Drive
- Storage Area Networks (SANs)
- Telecommunications
