Features: ·2 Thermal-Diode Inputs
·Up to 25kHz PWM Output Frequency
·3 Selectable SMBus Addresses
·Local Temperature Sensor
·1°C Remote Temperature Accuracy
·Two PWM Outputs for Fan Drive (Open Drain; Can be Pulled Up to +13.5V)
·Programmable Fan-Control Characteristics
·Automatic Fan Spin-Up Ensures Fan Start
·Controlled Rate-of-Change Ensures Unobtrusive Fan-Speed Adjustments
·±3% Fan-Speed Measurement Accuracy
·Temperature Monitoring Begins at POR for Fail-Safe System Protection
·OT and THERM Outputs for Throttling or Shutdown
·Measures Temperatures Up to +150°CApplicationDesktop Computers
Notebook Computers
Projectors
Servers
Networking EquipmentPinout
SpecificationsVCC to GND...........................................................-0.3V to +6V
PWM1, PWM2, TACH1, and TACH2 to GND ......-0.3V to +13.5V
DXP1 and DXP2 to GND.........................-0.3V to +(VCC + 0.3V)
DXN to GND ......................................................-0.3V to +0.8V
SCL, SDA, THERM, OT, FANFAIL, ADD,
and ALERT to GND ..............................................-0.3V to +6V
SDA, OT, THERM, ALERT, FANFAIL,
PWM1, and PWM2 Current .............................-1mA to +50mA
DXN Current ..................................................................±1mA
ESD Protection (all pins, Human Body Model) ...............2000V
Continuous Power Dissipation (TA = +70°C)
16-Pin QSOP (derated 8.3mW/°C above +70°C) .... 667mW
16-Pin TQFN 5mm x 5mm
(derated at 33.3mW/°C above +70°C)................2666.7mW
Operating Temperature Range ..................-40°C to +125°C
Junction Temperature.................................................+150°C
Storage Temperature Range .....................-65°C to +150°C
Lead Temperature (soldering, 10s) ...........................+300°C
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
DescriptionThe MAX6639 monitors its own temperature and one external diode-connected transistor or the temperatures of two external diode-connected transistors, typically available in CPUs, FPGAs, or GPUs. The 2-wire serial interface of MAX6639 accepts standard System Management Bus (SMBusTM) write byte, read byte, send byte, and receive byte commands to read the temperature data and program the alarm thresholds. Temperature data of MAX6639 can be read at any time over the SMBus, and three programmable alarm outputs can be used to generate interrupts, throttle signals, or overtemperature shutdown signals.
The temperature data of MAX6639 is also used by the internal dual-PWM fan-speed controller to adjust the speed of up to two cooling fans, thereby minimizing noise when the system is running cool, but providing maximum cooling when power dissipation increases. Speed control of MAX6639 is accomplished by tachometer feedback from the fan, so that the speed of the fan is controlled, not just the PWM duty cycle. Accuracy of speed measurement is ±4%.The MAX6639 is available in 16-pin QSOP and 16-pin TQFN 5mm x 5mm packages. It operates from 3.0V to 5.5V and consumes just 500A of supply current.
MAX6639 Data Sheet
