Fan Controller/Driver with Factory-Programmed Temperature Thresholds

The MAX6665 is a fully integrated thermal switch with an internal power transistor for driving a cooling fan rated up to 24V and 250mA. When the MAX6665's temperature rises above a factory-programmed threshold, the active-low FANOUT pin becomes active and powers the fan.

The MAX6665 is available with factory-programmed fan activation threshold temperatures from +40°C to +70°C in 5°C increments. Accuracy of the fan activation trip point is ±1°C (typ) and ±3°C (max). The trip point's hysteresis is pin selectable to 1°C, 4°C, or 8°C. Two open-drain logic outputs indicate overtemperature con- ditions: active-low WARN is activated when the temperature is 15°C above the fan activation threshold, and OT is activated when the temperature is 30°C above the threshold. These features can be used to safely power down systems that are overheated.

The MAX6665 operates from a +2.7V to +5.5V power supply, and the associated fan can be powered from 4.5V to 24V. It is available in an 8-pin SO package and operates from -40°C to +125°C.

Applications

* Card Racks * Laboratory Instruments * Notebook and Desktop Computers * PC Power Supplies * Servers

* On-Chip 250mA Fan Switch

* No External Components Required

* Factory-Programmed Thresholds

* Two Overtemperature Warning Signals

* Pin-Selectable 1°C, 4°C, and 8°C Hysteresis

* Low 65µA Supply Current