Remote-Junction Temperature-Controlled Fan-Speed Regulator with SMBus Interface

Please check latest availability status for a specific part variant.


The MAX6660 is a remote temperature sensor and fan-speed regulator that provides a complete fan-control solution. The remote temperature sensor is typically a common-collector PNP, such as a substrate PNP of a microprocessor, or a diode-connected transistor, typically a low-cost, easily mounted 2N3904 NPN type or 2N3906 PNP type.

The device also incorporates a closed-loop fan controller that regulates fan speed with tachometer feedback. The MAX6660 compares temperature data to a fan threshold temperature and gain setting, both programmed over the SMBus by the user. The result is automatic fan control that is proportional to the remote-junction temperature. The temperature feedback loop can be broken at any time for system control over the speed of the fan.

Fan speed is voltage controlled as opposed to PWM controlled, greatly reducing acoustic noise and maximizing fan reliability. An on-chip power device drives fans rated up to 250mA.

Temperature data is updated every 0.25s and is readable at any time over the SMBus interface. The MAX6660 is accurate to 1°C (max) when the remote junction is between +60°C to +100°C. Data is formatted as a 10-bit + sign word with 0.125°C resolution.

The MAX6660 is specified for -40°C to +125°C and is available in a 16-pin QSOP package.
MAX6660: Typical Operating Circuit MAX6660: Typical Operating Circuit Enlarge+

Key Features

  • Integrated Thermal Sensing and Fan-Regulation Solution
  • Programmable Fan Threshold Temperature
  • Programmable Temperature Range for Full-Scale Fan Speed
  • Accurate Closed-Loop Fan-Speed Regulation
  • On-Chip Power Device Drives Fans Rated Up to 250mA
  • Programmable Under/Overtemperature Alarms
  • SMBus 2-Wire Serial Interface with Timeout (Cannot "Lock Up" the SMBus)
  • Supports SMBus Alert Response
  • ACPI Compatible, Including OVERT-bar System Shutdown Function
  • ±1°C (+60°C to +100°C) Thermal-Sensing Accuracy
  • MAX6660EVKIT Available


  • Industrial Control Systems
  • Notebook Computers
  • PC
  • Servers
  • Telecom Systems
  • Workstations
Part NumberSensor TypeFan Cntrl.InterfaceAccuracy
Temp. Thresh.
Temp. Resolution
See Notes
MAX6660 RemoteLinear2-Wire/I2C/SMBus1Programmable11
$3.75 @1k
See All Fan Controllers (21)
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.

MAX6660EVKIT: Evaluation System/Evaluation Kit for the MAX6660
MAX6660EVSYS: Evaluation System/Evaluation Kit for the MAX6660

CAD Symbols and Footprints

  • MAX6660AEE+
  • MAX6660AEE+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.

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