The MAX6678 monitors its own temperature and the
temperatures of two external diode-connected transistors,
which typically reside on the die of a CPU or other
integrated circuit. The device reports temperature values
in digital form using a 2-wire serial interface. The
MAX6678 provides a programmable alarm output to generate
interrupts, throttle signals, or overtemperature shutdown
signals.
The 2-wire serial interface accepts standard System
Management Bus (SMBus™) write byte, read byte, send
byte, and receive byte commands to read the temperature
data and program the alarm thresholds. The temperature
data controls a PWM output signal to adjust
the speed of a cooling fan, thereby minimizing noise
when the system is running cool, but providing maximum
cooling when power dissipation increases.
Five GPIO pins provide additional flexibility. The GPIO
power-up states are set by connecting the GPIO preset
inputs to ground or VCC.
The MAX6678 is available in a 20-pin QSOP package
and a 5mm x 5mm thin QFN package. It operates from
3.0V to 5.5V and consumes just 500µA of supply current.
Key Features
Applications/Uses
Two Thermal-Diode Inputs
Local Temperature Sensor
Five GPIO Input/Outputs
Two PWM Outputs for Fan Drive (Open Drain; May Be Pulled Up to +5V)
Programmable Fan-Control Characteristics
Automatic Fan Spin-Up Ensures Fan Start
Controlled Rate of Change Ensures Unobtrusive Fan-Speed Adjustments
1°C Remote Temperature Accuracy (+60°C to +145°C)
Temperature Monitoring Begins at POR for Fail-Safe System Protection
OT-bar Output for Throttling or Shutdown
Four Versions Available, Each with a Different Address
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 prices
and delivery, please see the price and availability page
or contact an authorized distributor.