MAX6643/MAX6644/MAX6645 19-3305 Rev 2 3/07 Automatic PWM Fan-Speed Controllers with Overtemperature Output General Description Features The MAX6643/MAX6644/MAX6645 monitor temperature Simple, Automatic Fan-Speed Control and automatically adjust fan speed to ensure optimum Internal and External Temperature Sensing cooling while minimizing acoustic noise from the fan. Each device measures two temperature locations. Detect Fan Failure Through Locked-Rotor Output, The MAX6643/MAX6644/MAX6645 generate a PWM Tachometer Output, or Fan-Supply Current waveform that drives an external power transistor, which Sensing in turn modulates the fans power supply. The Multiple, 1.6% Output Duty-Cycle Steps for Low MAX6643/MAX6644/MAX6645 monitor temperature and Audibility of Fan-Speed Changes adjust the duty cycle of the PWM output waveform to con- trol the fans speed according to the cooling needs of the Pin-Selectable or Factory-Selectable Low- system. The MAX6643 monitors its own die temperature Temperature Fan Threshold and an optional external transistors temperature, while the Pin-Selectable or Factory-Selectable High- MAX6644 and MAX6645 each monitor the temperatures Temperature Fan Threshold of one or two external diode-connected transistors. The MAX6643 and MAX6644 have nine selectable trip Spin-Up Time Ensures Fan Start temperatures (in 5C increments). The MAX6645 is fac- Fan-Start Delay Minimizes Power-Supply Load at tory programmed and is not pin selectable. Power-Up All versions include an overtemperature output (OT). 32Hz PWM Output OT can be used for warning or system shutdown. The MAX6643 also features a FULLSPD input that forces the Controlled Duty-Cycle Rate-of-Change Ensures PWM duty cycle to 100%. The MAX6643/MAX6644/ Good Acoustic Performance MAX6645 also feature a FANFAIL output that indicates 2C Temperature-Measurement Accuracy a failed fan. See the Selector Guide for a complete list of each devices functions. FULLSPD/FULLSPD Input Sets PWM to 100% The MAX6643 and MAX6644 are available in a small Pin-Selectable OT Output Threshold 16-pin QSOP package and the MAX6645 is available in a 10-pin MAX package. All versions operate from 16-Pin QSOP and 10-Pin MAX Packages 3.0V to 5.5V supply voltages and consume 500A (typ) supply current. Ordering Information Applications Networking Equipment PIN- PKG PART TEMP RANGE PACKAGE CODE Storage Equipment MAX6643LBFAEE -40C to +125C 16 QSOP E16-1 Servers MAX6643LBBAEE -40C to +125C 16 QSOP E16-1 Desktop Computers MAX6644LBAAEE -40C to +125C 16 QSOP E16-1 Workstations MAX6645ABFAUB -40C to +125C 10 MAX U10-2 Pin Configurations, Typical Operating Circuit, and Selector Guide appear at end of data sheet. MAX is a registered trademark of Maxim Integrated Products, Inc. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLEAutomatic PWM Fan-Speed Controllers with Overtemperature Output ABSOLUTE MAXIMUM RATINGS V to GND..............................................................-0.3V to +6V Continuous Power Dissipation (T = +70C) DD A PWM OUT, OT, and FANFAIL to GND.....................-0.3V to +6V 16-Pin QSOP (derate 8.3mW/C above +70C).......... 667mW FAN IN1 and FAN IN2 to GND...........................-0.3V to +13.2V 10-Pin MAX (derate 5.6mW/C above +70C) ...........444mW DXP to GND.........................................................-0.3V to +0.8V Operating Temperature Range .........................-40C to +125C Junction Temperature......................................................+150C FULLSPD, FULLSPD, TH , TL , TACHSET, Storage Temperature Range ............................-65C to +150C and OT to GND ..................................-0.3V to +(V + 0.3V) DD Lead Temperature (soldering, 10s) .................................+300C FANFAIL, OT Current..........................................-1mA to +50mA 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 = +3.0V to +5.5V, T = -40C to +125C, unless otherwise noted. Typical values are at V = +3.3V, T = +25C.) (Note 1) DD A DD A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Operating Supply Voltage Range V +3.0 +5.5 V DD V = +3.3V, DD T = +20C to +60C 2 A Remote Temperature Error +20C T C RJ +100C T = 0C to +125C 3 A T = +10C to +70C 2.5 A Local Temperature Error V = +3.3V C CC T = 0C to +125C 3.5 A Temperature Error from Supply 0.2 C/V Sensitivity Power-On-Reset (POR) Threshold V falling edge 1.5 2.0 2.5 V DD POR Threshold Hysteresis 90 mV Operating Current I During a conversion 0.5 1 mA S Average Operating Current Duty cycle = 50%, no load 0.5 mA Remote-Diode Sourcing Current High level 80 100 120 A Conversion Time 125 ms Spin-Up Time MAX664 B 8 s Startup Delay MAX664 B 0.5 s Minimum Fan-Fail Tachometer 16 Hz Frequency PWM OUT Frequency F 32 Hz PWM OUT DIGITAL OUTPUTS (OT, FANFAIL, PWM OUT) Output Low Voltage (OT)V I = 1mA 0.4 V OL SINK I = 6mA 0.5 Output Low Voltage SINK V V OL (FANFAIL, PWM OUT) I = 1mA 0.4 SINK Output-High Leakage Current I V = 3.3V 1 A OH OH 2 MAX6643/MAX6644/MAX6645