MAX6684 fan-failure detector/driver

Maxim Integrated Products introduces the MAX6684 fan-failure detector/driver. The device is inserted in series with the low side of the fan and senses the fan current. Static fan current is interpreted by the device to indicate fan failure. The on-chip low-side power device drives 5V, 12V, and 24V fans rated up to 250mA (nominal). Because the device is sensing the fan's supply current to indicate fan functionality, no tachometer output on the fan is necessary.

Housed in a small 8-pin SO package, the MAX6684 detects fan failure- underspeed stalling and locked rotors in common DC brushless fans. Failure is reported to the system through an active-low open-drain output.

An ON/OFF-bar pin allows a microcontroller to turn the fan on or off. This feature enables the device to be used as an output power switch for PWM fan controllers.

The MAX6684 operates with a 3.0V to 5.5V supply voltage while connected to fans up to 24Vand operates over the -40 degrees Celsius to +85 degrees Celsius temperature range. Supply current is 3.4mA (max) when fan current is 300mA and standby current is just 10 microamps (max).

Maxim Integrated Products, 7250 N.W. Evergreen Pkwy, Hillsboro, OR 97124. Tel: 503-547-2016; Fax: 503-547-0142.