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Part: MAX6645
Category:
Power Management
-> Motor Controller/Drivers
Description: Automatic PWM Fan-speed Controllers With Overtemperature Output <<<>>>The MAX6643/MAX6644/MAX6645 Monitor Temperature And Automatically Adjust Fan Speed to Ensure Optimum Cooling While Minimizing Acoustic Noise From The Fan. Each Device Measures Two Temperature Locations. <<<>>>The MAX6643/MAX6644/MAX6645 Generate a PWM Waveform That Drives an External Power Transistor, Which in Turn Modulates The Fan's Power Supply. The MAX6643/MAX6644/MAX6645 Monitor Temperature And Adjust The Duty Cycle of The PWM Output Waveform to Control The Fan's Speed According to The Cooling Needs of The System. The MAX6643 Monitors Its Own Die Temperature And an Optional External Transistor's Temperature While The MAX6644 And MAX6645 Each Monitor The Temperatures of One or Two External Diode-connected Transistors. <<<>>><<<>>>The MAX6643/MAX6644/MAX6645 Are Available in H And L Versions. The H Versions Are Trimmed For Higher Temperature Trip Thresholds Than The L Versions. The MAX6643 And MAX6644 Have Nine Selectable Trip Temperatures (in 5 C Increments). The MAX6645 is Factory Programmed And is Not Pin Selectable. <<<>>><<<>>>All Versions Include an Overtemperature Output (OT-bar). Ot-bar CAN be Used For Warning or System Shutdown. The MAX6643 Also Features a Fullspd Input That Forces The PWM Duty Cycle to 100%. The MAX6643/MAX6644/ MAX6645 Also Feature a Fanfail-bar Output That Indicates a Failed Fan. See The Selector Guide For a Complete List of Each Device's Functions. <<<>>><<<>>>The MAX6643 And MAX6644 Are Available in a Small 16-pin Qsop Package And The MAX6645 is Available in a 10-pin µMAX Package. All Versions Operate From Supply Voltages From 3.0V to 5.5V And Consume 500µA (typ) Supply Current. <<<>>>KEY Features Applications <<<>>>Simple, Automatic Fan-speed Control <<<>>>Internal And External Temperature Sensing <<<>>>Detect Fan Failure Through Locked-rotor Output, Tachometer Output, or Fan-supply Current Sensing <<<>>>Multiple, 1.6% Output Duty-cycle Steps For Low Audibility of Fan-speed Changes <<<>>>Pin-Selectable or Factory-selectable Low- Temperature Fan Threshold <<<>>>Pin-Selectable or Factory-selectable High- Temperature Fan Threshold <<<>>>Spin-Up Time Ensures Fan Start <<<>>>Fan-Start Delay Minimizes Power-supply Load at Power-up <<<>>>32Hz PWM Output <<<>>>Controlled Duty-cycle Rate of Change Ensures Good Acoustic Performance <<<>>>2 C Temperature-measurement Accuracy <<<>>>FULLSPD-bar/FULLSPD Input Sets PWM to 100% <<<>>>Pin-Selectable Ot-bar Output Threshold <<<>>>16-Pin Qsop And 10-Pin µMAX Packages
Company: Maxim Integrated Products
Datasheet: Download MAX6645 datasheet File size : 770 kB
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Datasheet text preview:
19-3305; Rev 0; 5/04
Automatic PWM Fan-Speed Controllers with Overtemperature Output
General Description
The MAX6643/MAX6644/MAX6645 monitor temperature and automatically adjust fan speed to ensure optimum cooling while minimizing acoustic noise from the fan. Each device measures two temperature locations. T h e MAX6643/MAX6644/MAX6645 generate a PWM waveform that drives an external power transistor, which i n turn modulates the fan's power supply. The MAX6643/MAX6644/MAX6645 monitor temperature and adjust the duty cycle of the PWM output waveform to control the fan's speed according to the cooling needs of the system. The MAX6643 monitors its own die temperature and an optional external transistor's temperature while the MAX6644 and MAX6645 each monitor the temperatures of one or two external diode-connected transistors. The MAX6643/MAX6644/MAX6645 are available in H and L versions. The H versions are trimmed for higher temperature trip thresholds than the L versions. The MAX6643 and MAX6644 have nine selectable trip temperatures (in 5°C increments). The MAX6645 is factory programmed and is not pin selectable. All versions include an overtemperature output (OT). OT can be used for warning or system shutdown. The MAX6643 also features a FULLSPD input that forces the P W M duty cycle to 100%. The MAX6643/MAX6644/ MAX6645 also feature a FANFAIL output that indicates a failed fan. See the Selector Guide for a complete list of each device's functions. The MAX6643 and MAX6644 are available in a small 16-pin QSOP package and the MAX6645 is available in a 10-pin µMAX® package. All versions operate from supply voltages from 3.0V to 5.5V and consume 500µA (typ) supply current.
Features
Simple, Automatic Fan-Speed Control Internal and External Temperature Sensing Detect Fan Failure Through Locked-Rotor Output, Tachometer Output, or Fan-Supply Current Sensing Multiple, 1.6% Output Duty-Cycle Steps for Low Audibility of Fan-Speed Changes Pin-Selectable or Factory-Selectable LowTemperature Fan Threshold Pin-Selectable or Factory-Selectable HighTemperature Fan Threshold Spin-Up Time Ensures Fan Start Fan-Start Delay Minimizes Power-Supply Load at Power-Up 32Hz PWM Output Controlled Duty-Cycle Rate of Change Ensures Good Acoustic Performance 2°C Temperature-Measurement Accuracy FULLSPD/FULLSPD Input Sets PWM to 100% Pin-Selectable OT Output Threshold 16-Pin QSOP and 10-Pin µMAX Packages
MAX6643/MAX6644/MAX6645
Applications
Networking Equipment Storage Equipment Servers Desktop Computers Workstations
PART MAX6643LBFAEE MAX6643LAFAEE* MAX6643LBBAEE* MAX6643LABAEE* MAX6643HAFAEE* MAX6644LAAAEE* MAX6644HAFAEE*
Ordering Information
TEMP RANGE -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C PIN-PACKAGE 16 QSOP 16 QSOP 16 QSOP 16 QSOP 16 QSOP 16 QSOP 16 QSOP 10 µMAX 10 µMAX
Pin Configurations, Typical Operating Circuit, and Selector Guide appear at end of data sheet. µMAX is a registered trademark of Maxim Integrated Products, Inc.
MAX6645AAFAUB* MAX6645BAFAUB*
*Future product--contact factory for availability.
________________________________________________________________ Maxim Integrated Products
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For 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.
Automatic PWM Fan-Speed Controllers with Overtemperature Output MAX6643/MAX6644/MAX6645
ABSOLUTE MAXIMUM RATINGS
VDD to GND .....-0.3V to +6V PWM_OUT, OT, and FANFAIL to GND............-0.3V to +6V FAN_IN1 and FAN_IN2 to GND...-0.3V to +13.2V DXP_ to GND.........-0.3V to +0.8V FULLSPD, FULLSPD, TH_, TL_, TACHSET, and OT_ to GND .....-0.3V to +(VDD + 0.3V) FANFAIL, OT Current .........-1mA to +50mA Continuous Power Dissipation (TA = +70°C) 16-Pin QSOP (derate 8.3mW/°C above +70°C).......... 667mW 10-Pin µMAX (derate 5.6mW/°C above +70°C) ..444mW Operating Temperature Range .......-40°C to +125°C Junction Temperature ......+150°C Storage Temperature Range ....-65°C to +150°C Lead Temperature (soldering, 10s) .........+300°C
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
(VDD = +3.0V to +5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VDD = +3.3V, TA = +25°C.) (Note 1)
PARAMETER Operating Supply Voltage Range Remote Temperature Error SYMBOL VDD VDD = +3.3V, +20°C TRJ +100°C VCC = +3.3V TA = +20°C to +60°C TA = 0°C to +125°C TA = +10°C to +70°C TA = 0°C to +125°C ±0.2 VDD falling edge IS During a conversion Duty cycle = 50%, no load High level MAX664_ _A_ _ _ _ MAX664_ _B_ _ _ _ MAX664_ _A_ _ _ _ MAX664_ _B_ _ _ _ 80 100 125 2.5 8 2.5 0.5 16 FPWM_OUT VOL VOL IOH ISINK = 1mA ISINK = 6mA ISINK = 1mA VOH = 3.3V 32 0.4 0.5 0.4 1 1.5 2.0 90 0.5 1 0.5 120 2.5 CONDITIONS MIN +3.0 TYP MAX +5.5 ±2 °C ±3 ±2.5 ±3.5 °C °C/V V mV mA mA µA ms s s Hz Hz V V µA UNITS V
Local Temperature Error Temperature Error from Supply Sensitivity Power-On-Reset (POR) Threshold POR Threshold Hysteresis Operating Current Average Operating Current Remote-Diode Sourcing Current Conversion Time Spin-Up Time Startup Delay Minimum Fan-Fail Tachometer Frequency PWM_OUT Frequency Output Low Voltage (OT) Output Low Voltage (FANFAIL, PWM_OUT) Output High-Leakage Current DIGITAL OUTPUTS (OT, FANFAIL, PWM_OUT)
Note 1: All parameters tested at TA = +25°C. Specifications over temperature are guaranteed by design. 2 _______________________________________________________________________________________
Automatic PWM Fan-Speed Controllers with Overtemperature Output
ELECTRICAL CHARACTERISTICS (continued)
(VDD = +3.0V to +5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VDD = +3.3V, TA = +25°C.) (Note 1)
PARAMETER SYMBOL VDD = 5.5V VDD = 3.0V VDD = 3.0V VIN = GND or VDD -1 CONDITIONS MIN 3.65 2.2 0.8 +1 TYP MAX UNITS DIGITAL INPUTS (FULLSPD, FULLSPD, TACHSET) Logic Input High Logic Input Low Input Leakage Current VIH VIL V V µA
MAX6643/MAX6644/MAX6645
Note 1: All parameters tested at TA = +25°C. Specifications over temperature are guaranteed by design.
Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
OPERATING SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX6643 toc01
PWMOUT FREQUENCY vs. DIE TEMPERATURE
MAX6643 toc02
400
32.0
320
PWMOUT FREQUENCY (Hz) 3.0 3.5 4.0 4.5 5.0 5.5
360 SUPPLY CURRENT (µA)
31.8
31.6
280
31.4
240
31.2
200 SUPPLY VOLTAGE (V)
31.0 -40 -15 10 35 60 85 100 TEMPERATURE (°C)
PWMOUT FREQUENCY vs. SUPPLY VOLTAGE
MAX6643 toc03
TRIP-THRESHOLD ERROR vs. TRIP TEMPERATURE
MAX664_L VERSIONS
MAX6643 toc04
35
1.0
PWMOUT FREQUENCY (Hz)
34
TRIP-THRESHOLD ERROR (°C)
0.6
33
0.2
32
-0.2
31
-0.6
30 3.0 3.5 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE (V)
-1.0 20 40 60 80 100 TRIP TEMPERATURE (°C)
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