Evaluation Kit Design Tools Support Available Resources and Models Click here to ask an associate for production status of specific part numbers. Automatic PWM Fan-Speed Controllers MAX6643/MAX6644/ with Overtemperature Output MAX6645 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. Detect Fan Failure Through Locked-Rotor Output, Each device measures two temperature locations. Tachometer Output, or Fan-Supply Current Sensing The MAX6643/MAX6644/MAX6645 generate a PWM Multiple, 1.6% Output Duty-Cycle Steps for Low waveform that drives an external power transistor, which Audibility of Fan-Speed Changes in turn modulates the fans power supply. The MAX6643/ MAX6644/MAX6645 monitor temperature and adjust the Pin-Selectable or Factory-Selectable Low-Temperature Fan Threshold duty cycle of the PWM output waveform to control the fans speed according to the cooling needs of the system. Pin-Selectable or Factory-Selectable The MAX6643 monitors its own die temperature and High-Temperature Fan Threshold an optional external transistors temperature, while the Spin-Up Time Ensures Fan Start MAX6644 and MAX6645 each monitor the temperatures Fan-Start Delay Minimizes Power-Supply Load of one or two external diode-connected transistors. at Power-Up The MAX6643 and MAX6644 have nine selectable trip 32Hz PWM Output temperatures (in 5C increments). The MAX6645 is factory programmed and is not pin selectable. Controlled Duty-Cycle Rate-of-Change Ensures Good Acoustic Performance All versions include an overtemperature output (OT). OT can be used for warning or system shutdown. The 2C Temperature-Measurement Accuracy MAX6643 also features a FULLSPD input that forces FULLSPD Input Sets PWM to 100% the PWM duty cycle to 100%. The MAX6643/MAX6644/ Pin-Selectable OT Output Threshold MAX6645 also feature a FANFAIL output that indicates a failed fan. See the Selector Guide for a complete list of 16-Pin QSOP and 10-Pin MAX Packages each devices functions. The MAX6643 and MAX6644 are available in a small Ordering Information 16-pin QSOP package and the MAX6645 is available in a 10-pin MAX package. All versions operate from 3.0V PIN- PKG PART TEMP RANGE to 5.5V supply voltages and consume 500A (typ) supply PACKAGE CODE current. MAX6643LBFAEE -40C to +125C 16 QSOP E16-1 MAX6643LBBAEE -40C to +125C 16 QSOP E16-1 Applications MAX6644LBAAEE -40C to +125C 16 QSOP E16-1 Networking Equipment Storage Equipment MAX6645ABFAUB -40C to +125C 10 MAX U10-2 Servers Desktop Computers Workstations Pin Configurations, Typical Operating Circuit, and Selector Guide appear at end of data sheet. MAX is a registered trademark of Maxim Integrated Products, Inc. 19-3305 Rev 3 6/19 2019 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. One Analog Way, Wilmington, MA 01887 U.S.A. Tel: 781.329.4700 2019 Analog Devices, Inc. All rights reserved.MAX6643/MAX6644/ Automatic PWM Fan-Speed Controllers MAX6645 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 FULLSPD, TH , TL , TACHSET, Junction Temperature ......................................................+150C and OT to GND ................................-0.3V to +(V + 0.3V) Storage Temperature Range ............................ -65C to +150C DD FANFAIL, OT Current ......................................... -1mA to +50mA Lead Temperature (soldering, 10s) .................................+300C 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, T = +20C to +60C 2 DD A Remote Temperature Error +20C T C RJ T = 0C to +125C 3 +100C 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 Analog Devices 2 www.analog.com