DS1621:Digital Thermometer and Thermostat

The DS1621 Digital Thermometer and Thermostat provides 9-bit temperature readings, which indicate the temperature of the device. The thermal alarm output, TOUT is active when the temperature of the device exceeds a user-defined temperature TH. The output remains active until the temperature drops below user defined temperature TL, allowing for any hysteresis necessary. User-defined temperature settings are stored in nonvolatile memory so parts may be programmed prior to insertion in a system. Temperature settings and temperature readings are all communicated to/from the DS1621 over a simple 2-wire serial interface.

Key Features
  • Simply Adds Temperature Monitoring and Control to Any System
    • Measures Temperatures From -55°C to +125°C in 0.5°C Increments. Fahrenheit Equivalent is -67°F to 257°F in 0.9°F Increments
    • Temperature is Read as a 9-Bit Value (2-Byte Transfer)
    • Converts Temperature to Digital Word in Less than 1s
    • Thermostatic Settings are User Definable And Nonvolatile
  • Can Be Used in a Wide Variety of Applications
    • Power Supply Range (2.7V to 5.5V)
    • Data is Read From/Written Via a 2-Wire Serial Interface (Open Drain I/O Lines)
  • Saves Space
    • Temperature Measurements Require No External Components
    • 8-pin DIP or SO package (208-mil) Packages
DS1621: Functional Block Diagram
DS1621: Functional Block Diagram
Applications/Uses
  • Medical
  • Networking
  • Personal Computing
  • Routers/Switches
  • Test Measurement Systems
  • Wireless Base Stations
DataSheet
titleDownload file
DS1621 Data SheetDS1621.pdf
Parametrics
Part NumberSensor TypeFunctionsInterfaceChannelsAccuracy
(±°C)
Parasite Pwr.Temp. Thresh.Temp. Resolution
(bits)
Multi DroppableOper. Temp.
(°C)
Package/PinsBudgetary
Price
See Notes
DS1621LocalSingle Temperature Alarm2-Wire/I2C/SMBusOne0.5NoProgrammable (NV)9
10
11
12
Yes-55 to +125PDIP(N)/8
SOIC/8
SOIC(N)/8
$2.13 @1k
Quality and Environmental Data
Related Products
  • DS1631:High-Precision Digital Thermometer and Thermostat
  • DS1721:Digital Thermometer and Thermostat
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
DS1621No Longer AvailableDS1621+PDIP(N),;8 pin;81.9 mm²-55°C to +125°CNo
DS1621+ActivePDIP(N),;8 pin;79.7 mm²-55°C to +125°CLead Free
DS1621SNo Longer AvailableDS1621S+SOIC(N),;8 pin;30.9 mm²-55°C to +125°CNo
DS1621S+ActiveSOIC(N),;8 pin;30.9 mm²-55°C to +125°CLead Free
DS1621S+T&RActiveSOIC(N),;8 pin;30.9 mm²-55°C to +125°CLead Free
DS1621S+WActiveSOIC(N),;8 pin;30.9 mm²-55°C to +125°CLead Free
DS1621S/T&RNo Longer AvailableDS1621S+T&RSOIC(N),;8 pin;30.9 mm²-55°C to +125°CNo
DS1621S/T&R+WActiveSOIC(N),;8 pin;30.9 mm²-55°C to +125°CLead Free
DS1621VNo Longer AvailableDS1621V+SOIC,;8 pin;44.1 mm²-55°C to +125°CNo
DS1621V+ActiveSOIC,;8 pin;44.1 mm²-55°C to +125°CLead Free
Part NumberStatusRecommended ReplacementPackageTempRoHS
DS1621V+T&RActiveSOIC,;8 pin;44.1 mm²-55°C to +125°CLead Free
DS1621V/T&RNo Longer AvailableDS1621V+T&RSOIC,;8 pin;44.1 mm²-55°C to +125°CNo
DS1621.pdf DS1621
DS1621.pdf DS1621
DS1621.pdf DS1621
Understanding Multidrop Address Assignments for Thermal Sensors MAX7504
Package Thermal Resistance Values (Theta JA, Theta JC) for Temperature Sensors and 1-Wire Devices MAX31826
Using the DS1631 Temperature Sensor in DS1621 Applications DS1631
Reverse Compatibility of the DS1721 Digital Temperature Sensor with the DS1621 DS1721
DS1621.pdf DS1621
DS1621.pdf DS1621