MAX6620:Quad Linear Fan-Speed Controller

Industry’s First Linear Fan Controller with RPM Control—Controls Up to Four Fans with a Single IC

The MAX6620 controls the speeds of up to four fans using four independent linear voltage outputs. The drive voltages for the fans are controlled directly over the I²C interface. Each output drives the base of an external bipolar transistor or the gate of a FET in high-side drive configuration. Voltage feedback at the fan's power-supply terminal is used to force the correct output voltage. The MAX6620 offers two methods for fan control. In RPM mode, the MAX6620 monitors four fan tachometer logic outputs for precise (±1%) control of fan RPM and detection of fan failure. In DAC mode, each fan is driven with a voltage resolution of 9 bits and the tachometer outputs of the fans are monitored for failure. The DAC_START input selects the fan power-supply voltage at startup to ensure appropriate fan drive when power is first applied. A watchdog feature turns the fans fully on to protect the system if there are no valid I²C communications within a preset timeout period. The MAX6620 operates from a 3.0V to 5.5V power supply with low 250µA supply current, and the I²C-compatible interface makes it ideal for fan control in a wide range of cooling applications. The MAX6620 is available in a 28-pin TQFN package and operates over the -40°C to +125°C automotive temperature range.

Key Features
  • Controls Up to Four Independent Fans with Linear (DC) Drive
  • Uses Four External Low-Cost Pass Transistors
  • 1% Accuracy Precision RPM Control
  • Controlled Voltage Rate-Of-Change for Best Acoustics
  • I²C Bus Interface
  • 3.0V to 5.5V Supply Voltage Range
  • 250µA (typ) Operating Supply Current
  • 3µA (typ) Shutdown Supply Current
  • Small 5mm x 5mm Footprint
MAX6620: Typical Application Circuit
MAX6620: Typical Application Circuit
Applications/Uses
  • Communications Equipment
  • Consumer Products
  • Servers
  • Storage Equipment
DataSheet
titleDownload file
MAX6620 Data SheetMAX6620.pdf
Parametrics
Part NumberFan Controller FunctionsFan Cntrl.InterfacePackage/PinsBudgetary
Price
See Notes
MAX6620Fan Failure DetectorLinear2-Wire/I2C/SMBusTQFN/28$2.72 @1k
Design kits & evaluation modules
Related Products
  • MAX6639:2-Channel Temperature Monitor with Dual, Automatic, PWM Fan-Speed Controller
  • MAX6660:Remote-Junction Temperature-Controlled Fan-Speed Regulator with SMBus Interface
  • MAX6651:Fan-Speed Regulators and Monitors with SMBus/I²C-Compatible Interface
  • MAX6650:Fan-Speed Regulators and Monitors with SMBus/I²C-Compatible Interface
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX6620ATI+ActiveTQFN,;28 pin;26 mm²-40°C to +125°CLead Free
MAX6620ATI+TActiveTQFN,;28 pin;26 mm²-40°C to +125°CLead Free
MAX6620.pdf MAX6620
MAX6620.pdf MAX6620
Understanding Multidrop Address Assignments for Thermal Sensors MAX7504