MAX31740

Click here for production status of specific part numbers. MAX31740 Ultra-Simple Fan-Speed Controller General Description The MAX31740 is a sophisticated, yet easy-to-use fanspeed controller. It monitors the temperature of an external NTC thermistor and generates a PWM signal that can be used to control the speed of a 2, 3, or 4-wire fan. The fan control characteristics are set using external resistors, thereby eliminating the need for an external microcontroller. Controllable characteristics include the starting temperature for fan control, PWM frequency, fan speed at low temperatures, and slope of the temperature-dutycycle transfer function. Because the operating characteristics are selected by hardwired passive components, a simple, low-cost fanspeed controller can be implemented without the need for firmware development. This can dramatically reduce development time for the fan control function. The MAX31740 is available in a 2mm x 3mm, 8-pin TDFN package. Features ● Self-Contained PWM Fan Control—No Micro Needed ● Controls Speed of 2-, 3-, or 4-Wire Fans ● Resistors Set Fan Control Characteristics ● Smooth, Linearly Varying PWM Duty Cycle Minimizes Audibility of Fan Noise ● Accurately Monitors External Thermistor Temperature ● 3.0V to 5.5V Operating Voltage Range ● -40°C to +125°C Operating Temperature Range Applications ● Consumer Equipment ● Communications Equipment ● Computing Equipment ● Industrial Equipment Ordering Information appears at end of data s...