MAXIM MAX6665ASA40

The MAX6665 is a simple fan controller/driver that turns on the internal power transistor when its die temperature exceeds a factory-set threshold. By connecting a small (typically 5V to 12V, 100mA to 250mA) cooling fan to FANOUT, a simple on/off fan-control system is created. FANOUT drives the fan’s low side. The fan’s positive supply pin should be connected to its normal power-supply voltage (up to 24V nominal). To turn the fan on when the MAX6665’s die temperature is less than the threshold voltage, drive FORCEON low. This overrides the internal control circuitry and allows an external device to activate the fan. FANON is an active-high push-pull logic output that goes high when the fan is turned on, either when temperature exceeds the threshold or the fan is forced on. WARN is an active-low, open-drain digital output that indicates the MAX6665’s die temperature exceeds 15℃ above the fan trip threshold. WARN output serves as a warning that the system temperature has continued to rise well above the fan activation temperature. OT is an active-low open-drain digital output that indicates the MAX6665’s die temperature exceeds 30℃ above the fan trip threshold. It serves as a thermal shutdown output to the system in case of excessive temperature rise.

• On-Chip 250mA Fan Switch
• No External Components Required
• Factory-Programmed Thresholds
• Two Overtemperature Warning Signals
• Pin-Selectable 1℃, 4℃, and 8℃ Hysteresis
• Low 65μA Supply Current
• The MAX6665 is a fully integrated thermal switch with an internal power transistor for driving a cooling fan rated up to 24V and 250mA.
• The MAX6665 is available with factory-programmed fan activation threshold temperatures from +40℃ to +70℃ in 5℃ increments.
• Accuracy of the fan activation trip point is ±1℃ (typ) and ±3℃ (max).
• The trip point’s hysteresis is pin selectable to 1℃, 4℃, or 8℃.
• Two open-drain logic outputs indicate overtemperature conditions: WARN is activated when the temperature is 15℃ above the fan activation threshold, and OT is activated when the temperature is 30℃ above the threshold.
• 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℃ to +125℃.

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