Dual Remote/Local Temperature Sensors and Four-Channel Voltage Monitors

Please check latest availability status for a specific part variant.


The MAX6655/MAX6656 are precise voltage and temperature monitors. The digital thermometer reports the temperature of two remote sensors and its own die temperature. The remote sensors are diode-connected transistors—typically a low-cost, easily mounted 2N3906 PNP type—that replace conventional thermistors or thermocouples. Remote accuracy is ±1°C for multiple transistor manufacturers with no calibration necessary. The remote channels can also measure the die temperature of other ICs, such as microprocessors, that contain a substrate-connected PNP with its collector grounded and its base and emitter available for temperature-sensing purposes. The temperature is digitized with 11-bit resolution.

The MAX6655/MAX6656 also measure their own supply voltage and three external voltages with 8-bit resolution. Each voltage input's sensitivity is set to give approximately 3/4-scale output code when the input voltage is at its nominal value. The MAX6655 operates at +5V supply and its second voltage monitor is 3.3V. The MAX6656 operates on a +3.3V supply and its second voltage monitor is 5V.

The 2-wire serial interface accepts standard SMBus™ Write Byte, Read Byte, Send Byte, and Receive Byte commands to program the alarm thresholds and to read data. The MAX6655/MAX6656 also provide SMBus alert response and timeout functions. The MAX6655/MAX6656 measure automatically and autonomously, with the conversion rate programmable. The adjustable rate allows the user to control the supply current.

In addition to the SMBus active-low ALERT output, the MAX6655/MAX6656 feature an active-low OVERT output, which is used as a temperature reset that remains active only while the temperature is above the maximum temperature limit. The active-low OVERT output is optimal for fan control or for system shutdown.
MAX6655, MAX6656: Typical Application Circuit MAX6655, MAX6656: Typical Application Circuit Enlarge+

Key Features

  • Three Temperature Channels
    • Two Remote PN Junctions
    • One Local Sensor
  • Four Voltage Channels
    • +12V, +5V, +3.3V, +2.5V
    • Three External Monitors
    • One Internal Supply Monitor
  • 11-Bit, 0.125°C Resolution
  • High Accuracy: ±1°C Over +60°C to +100°C Temperature Range
  • Programmable Under/Over-Threshold Alarms
  • Programmable Power-Saving Mode
  • No Calibration Required
  • SMBus/I²C-Compatible Interface
  • Active-low OVERT Output for Fan Control and System Shutdown


  • Communication Systems
  • Computers: Desktop, Workstation, Server
  • Notebook Computers
  • Servers
  • Thin Clients
  • Workstations

See parametric specs for Temperature Sensors (113)

Part NumberSensor TypeAlarm OutputFunctionsInterfaceChannelsAccuracy
Parasite Pwr.Temp. Thresh.Temp. Resolution
Multi DroppableOper. Temp.
See Notes
MAX6655 Remote
Remote & Local Sensor
Voltage Monitor
2-Wire/I2C/SMBusTwo1NoProgrammable11Yes-55 to +125
$4.05 @1k
$3.16 @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.

MAX6655EVKIT: Evaluation System/Evaluation Kit for the MAX6655, MAX6656
MAX6655EVSYS: Evaluation System/Evaluation Kit for the MAX6655, MAX6656
Product Reliability Reports: MAX6655.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

Gesture Sensor for Automotive Applications

  • Low-Cost, Flexible Gesture-Sensing Solution for Automotive Applications
  • Low-Power, Low-Cost External CPU Processes Sensor Output
  • Supports Swipe, Rotation, and Proximity Gestures

Best-in-Class Optical Pulse Oximeter and Heart-Rate Sensor AFE for Wearable Health

  • Complete Single-Channel Optical Data Acquisition System
  • Ultra Low-Power Operation for Wearable Devices
  • Excellent Top-End Dynamic Range > 91dB in White Card Loop-Back Test (Nyquist Sample-to-Sample Variance)