MAX6645BAFAUB+T

Thermal Management Overview

The MAX6645BAFAUB+T is an automatic PWM fan-speed controller with overtemperature output. It operates from a 3.0V to 5.5V supply and consumes 500µA typical current. The device monitors one or two external diode-connected transistors for temperature sensing. It generates a 32Hz PWM waveform to drive an external power transistor, modulating fan speed based on cooling needs. Factory-programmed thresholds replace pin-selectable options found in other variants.

Thermal Management Feature Summary

• Automatic fan-speed control via PWM output driven by external power transistor
• Temperature monitoring of one or two external diode-connected transistors
• Overtemperature alarm output for system warning or shutdown
• Fan-fail detection through locked-rotor, tachometer, or current sensing

Thermal Management Applications

• Networking equipment thermal management
• Storage equipment cooling systems
• Server chassis ventilation control
• Desktop computer and workstation cooling

Thermal Management Procurement Notes

Verify the specific suffix BAFAUB against official Analog Devices documentation to confirm factory-programmed threshold settings and package type. Confirm availability status as distribution channels may list limited stock or obsolete status. Ensure the ordering code matches the required 10-pin µMAX package configuration for your design.

Thermal Management Selection Notes

Select this part when fixed factory-programmed temperature thresholds are preferred over pin-selectable configurations. It supports dual remote diode inputs for comprehensive thermal monitoring. The 10-pin µMAX package offers a compact solution for space-constrained designs requiring automatic fan control without external microcontroller intervention.

Thermal Management Part Context

This component belongs to the MAX6643/MAX6644/MAX6645 family of automatic PWM fan-speed controllers. Unlike the MAX6643 and MAX6644 which offer pin-selectable thresholds, the MAX6645 variant features factory-programmed high and low temperature trip points. It shares the same core functionality of temperature-based fan modulation and fault detection within the series.

Thermal Management Replacement Considerations

Direct functional substitutes include MAX6643LBFAEE+ and MAX6644LBAAEE+. Note that these alternatives require external resistor networks or pin connections to set temperature thresholds, whereas the MAX6645BAFAUB+T has fixed factory settings.