MAX1989:Multichannel Remote/Local Temperature Sensors

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.

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
MAX1668, MAX1805, MAX1989: Typical Operating Circuit
MAX1668, MAX1805, MAX1989: Typical Operating Circuit
Applications/Uses
  • Central Office Telecom Equipment
  • Desktop/Notebook Computers
  • Industrial Controls
  • LAN Servers
  • Multichip Modules
  • Test and Measurement Equipment
DataSheet
titleDownload file
MAX1668-MAX1989 Data SheetMAX1668-MAX1989.pdf
Parametrics
Part NumberSensor TypeAlarm OutputFunctionsInterfaceChannelsAccuracy
(±°C)
Parasite Pwr.Temp. Resolution
(bits)
Oper. Temp.
(°C)
Package/PinsBudgetary
Price
See Notes
MAX1668RemoteAlertRemote & Local Sensor2-Wire/I2C/SMBusFour2No8-55 to +125QSOP/16$4.04 @1k
MAX1805TwoQSOP/16$3.35 @1k
MAX1989FourQSOP/16
TSSOP/16
$3.82 @1k
Design kits & evaluation modules
Quality and Environmental Data
Related Products
  • MAX1668:Multichannel Remote/Local Temperature Sensors
  • MAX1805:Multichannel Remote/Local Temperature Sensors
  • MAX1669:Fan Controller and Remote Temperature Sensor with SMBus Serial Interface
  • MAX1617:Remote/Local Temperature Sensor with SMBus Serial Interface
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX1989MEENo Longer AvailableMAX1989MEE+QSOP,;16 pin;30.9 mm²-40°C to +85°CNo
MAX1989MEE+ActiveQSOP,;16 pin;30.9 mm²-55°C to +125°CLead Free
MAX1989MEE+TActiveQSOP,;16 pin;30.9 mm²-55°C to +125°CLead Free
MAX1989MEE-TNo Longer AvailableMAX1989MEE+TQSOP;16 pin-40°C to +85°CSee data sheet
MAX1989MEE/GG8ActiveQSOP,;16 pin;30.9 mm²-55°C to +125°CNo
MAX1989MUENo Longer AvailableMAX1989MUE+TSSOP,;16 pin;33.4 mm²-40°C to +85°CNo
MAX1989MUE+ActiveTSSOP,;16 pin;33.4 mm²-55°C to +125°CLead Free
MAX1989MUE+TActiveTSSOP,;16 pin;33.4 mm²-40°C to +85°CLead Free
MAX1989MUE-TNo Longer AvailableMAX1989MUE+TTSSOP;16 pin-40°C to +85°CSee data sheet
MAX1668-MAX1989.pdf MAX1989
MAX1989.pdf MAX1989
MAX1668-MAX1989.pdf MAX1989