TC642 Microchip, TC642 Datasheet
TC642
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TC642 Summary of contents
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... MIN GND 4 General Description The TC642 is a switch mode fan speed controller for use with brushless DC fans. Temperature proportional speed control is accomplished using pulse width mod- ulation (PWM). A thermistor (or other voltage output temperature sensor) connected to the V nishes the required control voltage of 1.25V to 2.65V (typical) for 0% to 100% PWM duty cycle ...
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... Functional Block Diagram MIN V SHDN GND DS21444C-page 2 + – – V OTF + OTF – SHDN + Control Logic PWM Timer Clock Generator Start-up Timer + – Missing Pulse Detect TC642 + – 10k 70mV (typ OUT FAULT SENSE 2002 Microchip Technology Inc. ...
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... V x 0.19 — — — — 0.3 — 32/F — — 32/F — — 3/F — TC642 Units Test Conditions V mA Pins 6, 7 Open µ C(MAX) µA Pins 6, 7 Open µ 0.35V, F MIN Note 1 µA Note 1 µsec mA, Note 1 OH µ ...
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... PWM duty cycle (1.25V to 2.65V = 0% to 100%, typi- cal). The TC642 enters shutdown mode when During shutdown, the FAULT output is inactive SHDN and supply current falls to 25 µA (typical). The TC642 exits shutdown mode when V MIN Section 5.0, “Typical Applications”). DS21444C-page 4 2 ...
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... Normal fan start-up is then attempted as previously described. The FAULT output may be connected to external logic (or the interrupt input of a OUT microcontroller) to shut the TC642 down if multiple fault pulses are detected at approximately one second intervals. Diode D R are provided to ensure fan restarts are the result fan fault and not an over-temperature fault ...
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... TC642 The second condition by which the TC642 detects a fault is when the PWM control voltage applied to V becomes greater than that needed to drive 100% duty cycle (see Section 1.0, “Electrical Characteristics”). This indicates that the fan is at maximum drive and the potential exists for system overheating. Either heat dis- sipation in the system has gone beyond the cooling system’ ...
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... Quit Normal Operation and go to Fan Fault. (10) End. 2002 Microchip Technology Inc. 4.3 Fan Fault Fan fault is an infinite loop wherein the TC642 is latched in shutdown mode. This mode can only be released by a reset (i.e then above V SHDN ...
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... Normal No Operation Fan Fault Fan Fault FAULT = OUT No V < MIN SHDN Yes No V > MIN REL Yes Power-up FIGURE 4-1: TC642 Behavioral Algorithm Flowchart. DS21444C-page 8 Normal Operaton Clear Missing Pulse Detector V < MIN SHDN No > REL No Yes V > OTF No V ...
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... TC642 cir- cuits and prototyping aids. The TC642DEMO is a printed circuit board optimized for small size and ease of inclusion into system prototypes. The TC642EV is a larger board intended for benchtop development and analysis. At the very least, anyone contemplating a ...
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... V node added benefit, this IN configuration produces an output voltage delta of 1.4V, which is well within the range of the V specification of the TC642. A 100 k NTC thermistor is selected for this application in order to keep I minimum. For the voltage range equal to 1.25V to IN 2.65V, the temperature range of this configuration is 0° ...
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... Operations at Low Duty Cycle One boundary condition which may impact the selec- tion of the minimum fan speed is the irregular activation of the Diagnostic Timer due to the TC642 “missing” fan commutation pulses at low speeds. This is a natural consequence of low PWM duty cycles (typically 25% or less) ...
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... Output Drive Transistor Selection The TC642 is designed to drive an external transistor or MOSFET for modulating power to the fan. This is shown Figures 3-1, 5-1, 5-4, 5-6, 5-7, 5-8 1 and 5-9. The V pin has a minimum source current OUT and a minimum sink current of 1 mA. Bipolar transistors or MOSFETs may be used as the power switching element, as shown in Figure 5-7 ...
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... OUT V DD Fan R BASE V Q OUT SENSE GND b) Darlington Transistor Pair + 2 OUT Fan D 1 12.0V TC642 Zener Q GND -12V TC642 , causing Q to turn on. Operation is OUT Fan OUT R SENSE GND c) N-Channel MOSFET * 2.2 DS21444C-page 13 1 ...
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... V divider or shutdown circuit) is MIN powered by a supply different from that of the TC642. Care should be taken to ensure that the TC642’s V supply powers up first. If possible, the networks attached to V and V should connect to the V ...
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... In addition, the V input should be bypassed DD with a 1 µF capacitor. Grounds should be kept as short as possible. To keep fan noise off the TC642 ground pin, individual ground returns for the TC642 and the low side of the fan current sense resistor should be used. + ...
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... Output codes 001[B] to 111[B] operate the fan from roughly 40% to 100% of full speed. An open-drain output from the processor (I/O0) can be used to reset the TC642 following detection of a fault condition. The FAULT output can be connected to the processor's interrupt input I/O pin, for polled operation. ...
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... Standard marking consists of Microchip part number, year code, week code, traceability code (facility code, mask rev#, and assembly code). For marking beyond this, certain price adders apply. Please check with your Microchip Sales Office. 2002 Microchip Technology Inc. TC642 Example: TC642CPA 025 0215 Example: TC642COA 0215 025 Example: TC642E 215025 DS21444C-page 17 ...
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... TC642 8-Lead Plastic Dual In-line (P) – 300 mil (PDIP Dimension Limits Number of Pins Pitch Top to Seating Plane Molded Package Thickness Base to Seating Plane Shoulder to Shoulder Width Molded Package Width Overall Length Tip to Seating Plane Lead Thickness Upper Lead Width ...
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... A1 .004 .007 .010 E .228 .237 .244 E1 .146 .154 .157 D .189 .193 .197 h .010 .015 .020 L .019 .025 .030 .008 .009 .010 B .013 .017 .020 TC642 A2 MILLIMETERS MIN NOM MAX 8 1.27 1.35 1.55 1.75 1.32 1.42 1.55 0.10 0.18 0.25 5.79 6.02 6.20 3.71 3.91 3.99 4.80 4.90 5.00 0.25 0.38 0.51 0.48 0.62 0. 0.20 0.23 0.25 0.33 0.42 0. ...
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... TC642 8-Lead Plastic Micro Small Outline Package (MS) (MSOP (F) Dimension Limits Number of Pins Pitch Overall Height Molded Package Thickness Standoff § Overall Width Molded Package Width Overall Length Foot Length Footprint (Reference) Foot Angle Lead Thickness Lead Width Mold Draft Angle Top ...
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... Standard Reel Component Orientation for 713 Suffix Device Pitch (P) Part Per Full Reel 2500 User Direction of Feed P Standard Reel Component Orientation for 713 Suffix Device Pitch (P) Part Per Full Reel 2500 TC642 W Reel Size Reel Size 13 in DS21444C-page 21 ...
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... TC642 NOTES: DS21444C-page 22 2002 Microchip Technology Inc. ...
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... Microchip's development systems software products. Plus, this line provides information on how customers ® ® can receive the most current upgrade kits.The Hot Line or Microsoft Numbers are: 1-800-755-2345 for U.S. and most of Canada, and 1-480-792-7302 for the rest of the world. TC642 092002 DS21444C-page23 ...
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... Telephone: (_______) _________ - _________ Application (optional): Would you like a reply? Y Device: TC642 Questions: 1. What are the best features of this document? 2. How does this document meet your hardware and software development needs you find the organization of this document easy to follow? If not, why? 4 ...
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... Examples: a) TC642COA: PWM Fan Speed Controller w/ Fault Detection, SOIC package. b) TC642COA713: PWM Fan Speed Controller w/ Fault Detection, SOIC package, Tape and Reel. c) TC642CPA: PWM Fan Speed Controller w/ Fault Detection, PDIP package. d) TC642EUA: PWM Fan Speed Controller w/ Fault Detection, MSOP package. DS21444C-page25 ...
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... TC642 NOTES: DS21444C-page 26 2002 Microchip Technology Inc. ...
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... Microchip Technology Incorporated with respect to the accuracy or use of such information, or infringement of patents or other intellectual property rights arising from such use or otherwise. Use of Microchip’s products as critical com- ponents in life support systems is not authorized except with express written approval by Microchip. No licenses are con- veyed, implicitly or otherwise, under any intellectual property rights ...
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... Mississauga, Ontario L4V 1X5, Canada Tel: 905-673-0699 Fax: 905-673-6509 DS21444C-page ALES AND ERVICE ASIA/PACIFIC Australia Microchip Technology Australia Pty Ltd Suite 22, 41 Rawson Street Epping 2121, NSW Australia Tel: 61-2-9868-6733 Fax: 61-2-9868-6755 China - Beijing Microchip Technology Consulting (Shanghai) Co., Ltd., Beijing Liaison Office Unit 915 Bei Hai Wan Tai Bldg ...