MAX1668

Multichannel Remote/Local Temperature Sensors


Please check latest availability status for a specific part variant.

Description

The MAX1668/MAX1805/MAX1989 are precise multichannel digital thermometers that report the temperature of all remote sensors and their own packages. The remote sensors are diode-connected transistors—typically low-cost, easily mounted 2N3904 NPN types—that replace conventional thermistors or thermocouples. Remote accuracy is ±3°C for multiple transistor manufacturers, with no calibration needed. The remote channels can also measure the die temperature of other ICs, such as microprocessors, that contain an on-chip, diode-connected transistor.

The 2-wire serial interface accepts standard system management bus (SMBus™) write byte, read byte, send byte, and receive byte commands to program the alarm thresholds and to read temperature data. The data format is 7 bits plus sign, with each bit corresponding to 1°C, in two's-complement format.

The MAX1668/MAX1805/MAX1989 are available in small, 16-pin QSOP surface-mount packages. The MAX1989 is also available in a 16-pin TSSOP.
MAX1668, MAX1805, MAX1989: Typical Operating Circuit MAX1668, MAX1805, MAX1989: Typical Operating Circuit Enlarge+

Key Features

  • Multichannel
    • 4 Remote, 1 Local (MAX1668/MAX1989)
    • 2 Remote, 1 Local (MAX1805)
  • No Calibration Required
  • SMBus 2-Wire Serial Interface
  • Programmable Under/Overtemperature Alarms
  • Supports SMBus Alert Response
  • Accuracy
    • ±2°C (+60°C to +100°C, Local)
    • ±3°C (-40°C to +125°C, Local)
    • ±3°C (+60°C to +100°C, Remote)
  • 3µA (typ) Standby Supply Current
  • 700µA (max) Supply Current
  • Small, 16-Pin QSOP/TSSOP Packages

Applications/Uses

  • Central Office Telecom Equipment
  • Desktop/Notebook Computers
  • Industrial Controls
  • LAN Servers
  • Multichip Modules
  • Test and Measurement Equipment
Part NumberSensor TypeAlarm OutputFunctionsInterfaceChannelsAccuracy
(±°C)
Parasite Pwr.Temp. Resolution
(bits)
Oper. Temp.
(°C)
Package/PinsBudgetary
Price
See Notes
MAX1668 RemoteAlertRemote & Local Sensor2-Wire/I2C/SMBusFour2No8-55 to +125
QSOP/16
$4.04 @1k
MAX1805 Two
QSOP/16
$3.35 @1k
MAX1989 Four
QSOP/16
TSSOP/16
$3.82 @1k
See All Temperature Sensors (111)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Technical Documents

App Note 694 Temperature Sensor ICs Simplify Designs
App Note 687 Distributed Temperature Sensing Improves Reliability

Quality and Environmental Data

Product Reliability Reports: MAX1668.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

Additional Resources

Temperature Family by Product Type

CAD Symbols and Footprints

  • MAX1668MEE+
  • MAX1668MEE+T
  • Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

    Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

    Quality Management System >
    Environmental Management System >

     
    Status:
    Package:
    Temperature:

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