19-2056; Rev 0; 5/01 Fan Controller/Driver with Factory-Programmed Temperature ThresholdsMAX6665General DescriptionFeatures The MAX6665 is a fully integrated thermal switch with ♦ On-Chip 250mA Fan Switch an internal power transistor for driving a cooling fan rated up to 24V and 250mA. When the MAX6665’s tem- ♦ No External Components Required perature rises above a factory-programmed threshold, ♦ Factory-Programmed Thresholds the FANOUT pin becomes active and powers the fan. ♦ Two Overtemperature Warning Signals The MAX6665 is available with factory-programmed fan activation threshold temperatures from +40°C to +70°C ♦ Pin-Selectable 1°C, 4°C, and 8°C Hysteresis in 5°C increments. Accuracy of the fan activation trip ♦ Low 65µA Supply Current point is ±1°C (typ) and ±3°C (max). The trip point’s hys- teresis is pin selectable to 1°C, 4°C, or 8°C. Two open- drain logic outputs indicate overtemperature con- Ordering Information ditions: WARN is activated when the temperature is 15°C above the fan activation threshold, and OT is acti- vated when the temperature is 30°C above the thresh- TEMP.PIN-PARTTHRESHOLD old. These features can be used to safely power down RANGEPACKAGE systems that are overheated. -40°C to MAX6665ASA40 8 SO-EP* 40°C The MAX6665 operates from a +2.7V to +5.5V power +125°C supply, and the associated fan can be powered from -40°C to 4.5V to 24V. It is available in an 8-pin SO package and MAX6665ASA45 8 SO-EP* 45°C +125°C operates from -40°C to +125°C. -40°C to Applications MAX6665ASA50 8 SO-EP* 50°C +125°C Notebook and Desktop Computers -40°C to MAX6665ASA55 8 SO-EP* 55°C Servers +125°C PC Power Supplies -40°C to MAX6665ASA60 8 SO-EP* 60°C +125°C Laboratory Instruments -40°C to Card Racks MAX6665ASA65 8 SO-EP* 65°C +125°C Typical Operating Circuit -40°C to MAX6665ASA70 8 SO-EP* 70°C +125°C +4.5V TO +24V *Exposed paddle 100mA TO 250mA COOLING FAN Pin Configuration TOP VIEW +3.3V VDD FANOUT VDD 1µF MAX6665 100kΩ GND 1 8 FANOUT HYST WARN VDD FORCEON 2 7 VDD MAX6665 100kΩ HYST 3 6 WARN FORCEON OT FANON 4 5 OT FANON GND SO________________________________________________________________ Maxim Integrated Products1For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.