MAX6668/MAX6670 19-2133 Rev 2 11/02 Remote Temperature Switches with Integrated Fan Controller/Driver General Description Features The MAX6668/MAX6670 remote-junction thermal +12V, 250mA Integrated Fan Driver switches with an internal power transistor drive a cool- No Calibration Required ing fan rated for supply voltages up to +12V and 250mA. These devices measure the temperature of an Pin-Selectable 4C, 8C, or 12C Hysteresis external P-N junction (typically a diode-connected tran- (MAX6670) sistor) and turn on the fan power switch when the Factory-Programmed Temperature Thresholds remote temperature rises above a factory-programmed threshold. Self-contained and requiring no software from +40C to +75C development, the MAX6668/MAX6670 are simple Overtemperature Warning Signals drop-in fan-control solutions for a variety of systems. 110A (typ) Supply Current The MAX6670 features an open-drain WARN output that goes active when the remote temperature exceeds Space-Saving 8-Pin and 10-Pin MAX Packages the factory-programmed fan activation threshold by +15C. The MAX6670 features an open-drain OT output that goes active when the remote temperature exceeds Ordering Information the factory-programmed threshold by +30C. The T H R ESH- MAX6668/MAX6670 provide a fan-control input, TEMP PI N- PART O L D FORCEON, that allows the fan to be driven externally, RANGE PA C K A G E regardless of temperature. ( C ) Available temperature thresholds range from +40C to MAX6668AUA40 -40C to +125C 8 MAX 40 +75C in 5C increments. Hysteresis is preset to 8C on MAX6668AUA45 -40C to +125C 8 MAX 45 the MAX6668 or pin selectable to 4C, 8C, or 12C MAX6668AUA50 -40C to +125C 8 MAX 50 using a three-level logic input on the MAX6670. MAX6668AUA60 -40C to +125C 8 MAX 60 Temperature threshold accuracy is 1C (typ) and 2.2C (max) for remote-junction temperatures from MAX6668AUA70 -40C to +125C 8 MAX 70 +40C to +75C. MAX6668AUA75 -40C to +125C 8 MAX 75 The MAX6668/MAX6670 operate from a +3V to +3.6V Ordering Information continued at end of data sheet. power supply, and are specified over the automotive temperature range (-40C to +125C). The MAX6668 is offered in an 8-pin MAX package and the MAX6670 is Typical Application Circuit available in a space-saving 10-pin MAX package. Applications +12V Notebook and Desktop Computers 250mA Network Switches +3.3V FAN PC Power Supplies V DD DXP FANOUT Laboratory Instruments V DD C S 10k Card Racks 2200pF MAX6670 Temperature Alarms 2N3904 DXN WARN Fan Controls V DD 10k HYST OT V FORCEON DD GND PGND Pin Configuration appears at end of data sheet. Typical Operating Circuit appears at end of data sheet. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.Remote Temperature Switches with Integrated Fan Controller/Driver ABSOLUTE MAXIMUM RATINGS V to GND..............................................................-0.3V to +6V Continuous Power Dissipation (T = +70C) DD A PGND to GND .......................................................-0.3V to +0.3V 8-Pin MAX (derate 4.1mW/C above +70C).............333mW FANOUT to GND ....................................................-0.3V to +15V 10-Pin MAX (derate 5.6mW/C above +70C) ...........444mW DXN to GND ..........................................................-0.3V to +0.8V Operating Temperature Range .........................-40C to +125C DXP, WARN, HYST, FORCEON, OT...........-0.3V to (V + 0.3V) Storage Temperature Range .............................-60C to +150C DD Current into V , GND, DXP, DXN, WARN, HYST, Junction Temperature......................................................+150C DD FORCEON, OT..............................................................20mA Lead Temperature (soldering, 10s) .................................+300C Current into FANOUT, PGND ........................................ 300mA Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = +3V to +3.6V, T = -40C to +125C, unless otherwise noted. Typical values are at V = +3.3V and T = +25C.) DD A DD A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER SUPPLY Power-Supply Range V 3 3.6 V DD Average Supply Current I 110 200 A DD Operating Current During sampling 400 650 A Power-On Reset (POR) Threshold POR V falling edge 1 1.5 2.0 V DD POR Threshold Hysteresis 50 mV TEMPERATURE SENSOR T = +40C to +75C (Note 1), RJ 1 2.2 T = 0C to +85C, V = +3.3V A DD FANOUT Temperature T C TH Threshold Accuracy T = +40C to +75C (Note 1), RJ 1 4 T = -40C to +125C, V = +3.3V A DD HYST = GND 4 MAX6670 HYST = float 8 FANOUT Temperature T C HYST Threshold Hysteresis HYST = V 12 DD MAX6668 8 WARN Temperature Threshold Relative to FANOUT temperature threshold +15 C (MAX6670 Only) OT Temperature Threshold Relative to FANOUT temperature threshold +30 C (MAX6670 Only) Supply Sensitivity of Temperature 1 1.6 C/V Threshold Temperature Sample Frequency 3.3 4 Hz FAN DRIVE OUTPUT FANOUT Output Voltage Low V I = 250mA 0.5 1 V OL SINK Thermal Shutdown 170 C Thermal Shutdown Hysteresis 20 C LOGIC INPUT/OUTPUT 0.8 x FORCEON Input High Voltage V V IH V DD 2 MAX6668/MAX6670