MAX31760:Precision Fan-Speed Controller with Nonvolatile Lookup Table

Customizable Lookup Table-Based Fan Controller Enables Smooth Control of Fan Speed to Reduce Acoustic Noise

The MAX31760 integrates temperature sensing along with precision PWM fan control. It accurately measures its local die temperature and the remote temperature of a discrete diode-connected transistor, such as a 2N3906, or a thermal diode commonly found on CPUs, graphics processor units (GPUs), and other ASICs. Multiple temperature thresholds, such as local high/overtemperature (OT) and remote high/overtemperature, can be set by an I2C-compatible interface. Fan speed is controlled based on the temperature reading as an index to a 48-byte lookup table (LUT) containing user-programmed PWM values. The flexible LUT-based architecture enables the user to program a smooth nonlinear fan speed vs. temperature transfer function to minimize acoustic fan noise. Two tachometer inputs allow measuring the speeds of two fans independently. The active-low FF/FS pin multiplexes an open-drain fan-failure output with a full-speed fan-drive input. When the local or remote OT threshold is exceeded, the active-low SHDN pin is asserted low and can be used to shut down the system. A dedicated active-low ALERT pin reports that either a local or remote high-temperature threshold has been exceeded. Active-low ALERT can be programmed to work in either fault indicator mode or interrupt mode. These features make the device a compact and complete solution for a single-fan or two-fan cooling system.

Key Features
  • Customizable 48-Byte Lookup Table (LUT)-Based Architecture Enables a Smooth Nonlinear Control Output that Reduces Acoustic Noise
  • Operating Settings Stored in Nonvolatile Memory for Automatic Operation at Power-On
  • Two Tachometer Inputs Provide Flexibility by Measuring the Speeds of Two Fans Independently
  • Accurately Senses Both Remote and Local Temperature, Allowing Multiple Temperature Thresholds to Be Set
MAX31760: Typical Application Circuit
MAX31760: Typical Application Circuit
Applications/Uses
  • NAS/DAS
  • Networking Equipment
  • Servers
  • STB/DVR
DataSheet
titleDownload file
MAX31760 Data SheetMAX31760.pdf
Parametrics
Part NumberSensor TypeFan Controller FunctionsFan Cntrl.InterfaceAccuracy
(±°C)
Temp. Thresh.
(°C)
Temp. Resolution
(bits)
Package/PinsBudgetary
Price
See Notes
MAX31760RemoteFan Failure Detector
Remote & Local Sensor
PWM2-Wire/I2C/SMBus2Programmable11QSOP/16$1.10 @1k
Design kits & evaluation modules
Quality and Environmental Data
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX31760AEE+ActiveQSOP,;16 pin;30.9 mm²-40°C to +125°CLead Free
MAX31760AEE+TActiveQSOP,;16 pin;30.9 mm²-40°C to +125°CLead Free
MAX31760.pdf MAX31760
MAX31760_cn.pdf MAX31760
MAX31760.pdf MAX31760
MAX31760_cn.pdf MAX31760
MAX31760.pdf MAX31760
MAX31760.pdf MAX31760