General Description
The MAX6640 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 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 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.

Features
♦ Two Thermal-Diode Inputs
♦ Local Temperature Sensor
♦ 1°C Remote Temperature Accuracy (+60°C to +100°C)
♦ 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
♦ ±4% Fan-Speed Measurement Accuracy
♦ Temperature Monitoring Begins at POR for FailSafe System Protection
♦ OT and THERM Outputs for Throttling or Shutdown
♦ Measures Temperatures Up to +150°C
♦ Tiny 5mm x 5mm 16-Pin TQFN and QSOP Packages

Applications
   Desktop Computers
   Notebook Computers
   Workstations
   Servers
   Networking Equipment