General Description

The MAX6643/MAX6644/MAX6645 monitor temperature and automatically adjust fan speed to ensure optimum cooling while minimizing acoustic noise from the fan. Each device measures two temperature locations.

Features

♦ Simple, Automatic Fan-Speed Control

♦ Internal and External Temperature Sensing

♦ Detect Fan Failure Through Locked-Rotor Output, Tachometer Output, or Fan-Supply Current Sensing

♦ Multiple, 1.6 Output Duty-Cycle Steps for Low Audibility of Fan-Speed Changes

♦ Pin-Selectable or Factory-Selectable LowTemperature Fan Threshold

♦ Pin-Selectable or Factory-Selectable HighTemperature Fan Threshold

♦ Spin-Up Time Ensures Fan Start

♦ Fan-Start Delay Minimizes Power-Supply Load at Power-Up

♦ 32Hz PWM Output

♦ Controlled Duty-Cycle Rate-of-Change Ensures Good Acoustic Performance

♦ 2°C Temperature-Measurement Accuracy

♦ FULLSPD/FULLSPD Input Sets PWM to 100

♦ Pin-Selectable OT Output Threshold

♦ 16-Pin QSOP and 10-Pin µMAX Packages

Applications

   Networking Equipment

   Storage Equipment

   Servers

   Desktop Computers

   Workstations