12-Bit Plus Sign Temperature Sensors with SMBus/I²C-Compatible Serial Interface

Please check latest availability status for a specific part variant.


The MAX6633/MAX6634/MAX6635 combine a temperature sensor, a programmable overtemperature alarm, and an SMBus™/I²C-compatible serial interface into a single package. They convert their die temperatures into digital values using internal analog-to-digital converters (ADCs). The result of the conversion is then held in a temperature register as a 12-bit + sign value, allowing 0.0625°C resolution, readable at any time through the serial interface. The devices are capable of reading temperatures up to +150°C.

The MAX6633/MAX6634/MAX6635 feature a shutdown mode that saves power by turning off everything except the power-on reset (POR) and the serial interface. The devices can be configured to separate addresses, allowing multiple devices to be used on the same bus.

The MAX6633 has four address pins, allowing up to 16 devices to be connected to a single bus. The MAX6634 has three address pins, allowing up to eight devices to be connected to a single bus. The MAX6635 has two address pins, allowing up to four devices to be connected to a single bus.

The MAX6633/MAX6634/MAX6635 make temperature data available for transfer over the serial interface. The MAX6634 incorporates a dual-mode active-low ALERT output (open drain) and can serve as an upgraded alternative to the LM75. The MAX6635 includes an active-low ALERT output and an active-low OVERT output (both open drain) and can function as an upgraded replacement for the LM76 in most applications. The MAX6634/MAX6635 feature user-programmable temperature thresholds. All three devices come in an 8-pin SO package.
MAX6633, MAX6634, MAX6635: Typical Operating Circuit MAX6633, MAX6634, MAX6635: Typical Operating Circuit Enlarge+

Key Features

  • +3V to +5.5V Supply Range
  • Accuracy
    • ±1°C max (0°C to +50°C)
    • ±1.5°C max (-20°C to +85°C)
    • ±2.5°C max (-40°C to +125°C)
    • ±2.5°C typ (+150°C)
  • User-Programmable Temperature Thresholds (MAX6634/MAX6635)
  • User-Configurable Alarm Output(s) (MAX6634/MAX6635)
  • Ability to Respond to SMBus/I²C-Compatible Alert Response Address (MAX6634/MAX6635)
  • Active-Low OVERT Output for System Shutdown (MAX6635)
  • Multiple Devices per Bus
    • 16 devices (MAX6633)
    • 8 devices (MAX6634)
    • 4 devices (MAX6635)


  • Battery-Temperature Alarms
  • PC Temperature Control

See parametric specs for Temperature Sensors (113)

Part NumberSensor TypeAlarm OutputInterface#ChannelsAccuracy
Parasite Pwr.Temp. Thresh.Temp. Resolution
Multi DroppableOper. Temp.
(See Notes)
MAX6633 Local-2-Wire/I2C/SMBusOne1No-13Yes-55 to +150
SOIC (N)/8
$1.63 @1k
MAX6634 AlertProgrammable
SOIC (N)/8
$1.68 @1k
SOIC (N)/8
$1.63 @1k

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.

MAX6635EVKIT: Evaluation Kit for the MAX6633, MAX6634, and MAX6635
Product Reliability Reports: MAX6634.pdf 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

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 >


Related Resources

Complete Optical Biosensing Module with Ultra-Low-Power Biometric Sensor Hub

  • Complete Biometric Sensor Hub
  • World-Class Algorithm for Wearable Applications

±0.25°C Accurate I2C Temperature Sensor

  • High Accuracy
  • Long Battery Life
  • Small Size

1-Wire® Temperature Sensor with ±1ºC Accuracy

  • 1-Wire Interface Requires Only One Port Pin for Communication
  • Unique 64-bit Serial Code Stored in an On-Board ROM
  • External Resistor Selects Address for Location Identification

Integrated Optical Sensor Module for Mobile Health

  • Miniature 3.5mm x 7.0mm x 1.5mm, 14-Pin Optical Module
  • Optical-Grade Glass for Long-Term Optimal and Robust Performance
  • Ultra-Low-Power Operation for Mobile Device