TC647B Microchip Technology Inc., TC647B Datasheet
TC647B
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TC647B Summary of contents
Page 1
... FAULT is also asserted if the PWM reaches 100% duty cycle (TC642B only), indicat- ing that maximum cooling capability has been reached and a possible overheating condition exists. The TC642B and TC647B devices are available in 8-pin plastic MSOP, SOIC and PDIP packages. The specified V DD temperature range of these devices is -40 to +85º ...
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... TC642B/TC647B Functional Block Diagram TC642B/TC647B V OTF Clock Generator V MIN V SHDN GND DS21756B-page Note Note: The V is for the TC642B device only. Control Logic 3xT PWM V Timer OUT Start-up Timer FAULT Missing Pulse Detect SENSE (typ) comparator OTF 2003 Microchip Technology Inc ...
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... V SHDN REL Input Leakage IN MIN Pulse-Width Modulator PWM Frequency Note 1: Ensured by design, tested during characterization. 2: For V < 3.7V, t and t DD STARTUP 2003 Microchip Technology Inc. TC642B/TC647B PIN FUNCTION TABLE Name +0.3V) MIN DD GND SENSE FAULT V OUT V DD Sym Min ...
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... TC642B/TC647B ELECTRICAL SPECIFICATIONS (CONTINUED) Electrical Specifications: Unless otherwise specified, all limits are specified for -40°C < T Parameters SENSE Input SENSE Input Threshold Voltage with V Respect to GND Blanking time to ignore pulse due to V turn-on OUT FAULT Output Output Low Voltage Missing Pulse Detector Timer ...
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... TIMING SPECIFICATIONS t STARTUP V OUT FAULT SENSE FIGURE 1-1: TC642B/TC647B Start-Up Timing. 33.3 msec ( µ OUT FAULT SENSE FIGURE 1-2: Fan Fault Occurrence. V OUT FAULT Minimum 16 pulses SENSE FIGURE 1-3: Recovery From Fan Fault. 2003 Microchip Technology Inc. TC642B/TC647B t DIAG DS21756B-page 5 ...
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... MIN 0.1 µF V MIN - .01 µF 0.1 µF 1 µF Note: C and C 5 FIGURE 1-4: TC642B/TC647B Electrical Characteristics Test Circuit. DS21756B-page µF 0.1 µ OUT TC642B TC647B K 6 FAULT 5 SENSE GND are adjusted to get the necessary 1 µF value. ...
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... 100 200 300 400 500 (mV FIGURE 2-3: PWM Source Current (I vs 2003 Microchip Technology Inc. TC642B/TC647B = 5V +25°C. A 30.50 30.00 29.50 29.00 28. 110 125 -40 -25 -10 FIGURE 2-4: Temperature. 170 Pins 6 & 7 Open 165 C F 160 155 = 4.0V 150 145 140 ...
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... TC642B/TC647B Note: Unless otherwise indicated -40 -25 - Temperature (ºC) FIGURE 2-7: FAULT V vs. OL Temperature. 2.610 V = 5.5V DD 2.600 2.590 V = 3.0V DD 2.580 µF F 2.570 -40 -25 - Temperature (ºC) FIGURE 2-8: V vs. Temperature. ...
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... V = 5.0V 0.80 DD 0.75 0. 4.0V 0.65 DD 0.60 0.55 0. 3.0V DD 0.45 0.40 -40 -25 - Temperature (ºC) FIGURE 2-15: V Threshold vs. REL Temperature. 2003 Microchip Technology Inc. TC642B/TC647B = 5V +25°C. A 2.630 2.625 2.620 V = 5.0V DD 2.615 2.610 2.605 2.600 2.595 95 110 125 -40 -25 -10 ) vs. FIGURE 2-16: OL Temperature. 100 ...
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... Analog Input (V ) MIN An external resistor divider connected to V minimum fan speed by fixing the minimum PWM duty cycle (1.20V to 2.60V = 0% to 100%, typical). The TC642B and TC647B devices enter shutdown mode when During shutdown, the FAULT MIN SHDN output is inactive and supply current falls to 30 µA (typical) ...
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... D = Duty Cycle FIGURE 4-1: Waveform. The TC642B and TC647B generate a pulse train with a typical frequency can be varied from 0% to 100%. The pulse train gener- ated by the TC642B/TC647B device drives the gate of an external N-channel MOSFET or the base of an NPN transistor (shown in Figure 4-2). See Section 5.5, “ ...
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... This will ensure that in all operating environ- ments, the fan will start and operate properly. An exam- ple of the start-up timing is shown in Figure 1-1. A key feature of the TC642B/TC647B device is the start-up timer. When power is first applied to the device, (when the device is brought out of the shutdown mode ...
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... Minimum Speed (V Pin) MIN For the TC642B and TC647B devices, pin 3 is the V pin. This pin is used for setting the minimum fan speed threshold. The minimum fan speed function provides a way to set a threshold for a minimum duty cycle on the V put ...
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... REL normal start-up routine. If, during a fan fault condition, the voltage at the V drops below the V TC647B device will continue to hold the FAULT line low and drive the V fault condition is then removed, the FAULT output will be released and the V duty cycle that is being commanded by the V The sink current capability of the FAULT output is listed in the “ ...
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... DC current. When a fan locked rotor condition and the TC642B/TC647B device is in PWM mode, it will see one current pulse each time the V turned on. The initial pulse blanker allows the TC642B/ TC647B device to ignore this pulse and recognize that the fan fault condition. 4.9 Behavioral Algorithms The behavioral algorithm for the TC642B/TC647B devices is shown in Figure 4-9 ...
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... Fan Fault FAULT = Low High OUT Yes Shutdown V <V ? MIN SHDN MIN No 16 Pulses Detected? Yes Normal Operation FIGURE 4-9: TC642B/TC647B Behavioral Algorithm. DS21756B-page 16 Normal Operation Clear Missing Pulse Detector V < MIN SHDN > REL No Yes V > OTF No V OUT ...
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... A very important factor to consider when selecting the PWM frequency for the TC642B/TC647B devices is the RPM rating of the selected fan and the minimum duty cycle that the fan will be operating at. For fans that have a full speed rating of 3000 RPM or less desirable to use a lower PWM frequency ...
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... FanSense Network (R SENSE The FanSense Network (comprised allows the TC642B and TC647B devices to SENSE detect commutation of the fan motor. R the fan current into a voltage. C voltage signal to the SENSE pin. The goal of the sense network is to provide a voltage pulse to the SENSE pin that has a minimum amplitude ...
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... Figure 5-4 shows some typical waveforms for the fan current and the voltage at the SENSE pin. FIGURE 5-4: Typical Fan Current and SENSE Pin Waveforms. 2003 Microchip Technology Inc. TC642B/TC647B Another important factor to consider when selecting the SENSE R value is the fan current value during a locked SENSE rotor condition ...
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... FIGURE 5-5: Fan Current During a Locked Rotor Condition. 5.5 Output Drive Device Selection The TC642B/TC647B is designed to drive an external NPN transistor or N-channel MOSFET as the fan speed modulating element. These two arrangements are shown in Figure 5-7. For lower current fans, NPN transistors are a very economical choice for the fan drive device ...
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... For this reason, the V pin should be bypassed with a IN 0.01 µF capacitor. In order to keep fan noise off of the TC642B/TC647B device ground, individual ground returns for the TC642B/TC647B and the low side of the fan current sense resistor should be used. 2003 Microchip Technology Inc. ...
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... TC642B/TC647B The fan used in the system is a Panasonic series fan, model number FBA06T12H. A fault indication is desired when the fan locked rotor condition. This signal is used to indicate to the system that cooling is not available and a warning should be issued to the user. No fault indication from the fan controller is necessary for an over-temperature condition, as this is being reported elsewhere ...
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... No over-temperature indication is necessary. Based on these specifications, the proper selection is the TC647B device. Step 3: Setting the PWM Frequency. The fan is rated at 4200 RPM with a 12V input. Since the goal is to run to a 40% duty cycle (roughly 40% fan ...
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... The goal again for selecting these values is to ensure that the signal at the SENSE pin amplitude under all operating conditions. This will ensure that the pulses are detected by the TC642B/TC647B device and that the fan operation is detected. The fan current waveform is shown in Figure 5-8 and, ...
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... FAULT output. The value for this resistor is system-dependent. 2003 Microchip Technology Inc. TC642B/TC647B + C VDD ® 1.0 µ FAULT 7 TC647B V OUT V MIN 5 SENSE C F GND were also B nodes. These is the 5 +12V ® Panasonic ...
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... TC642B/TC647B 6.0 PACKAGING INFORMATION 6.1 Package Marking Information 8-Lead PDIP (300 mil) XXXXXXXXX NNN YYWW 8-Lead SOIC (150 mil) XXXXXX XXXYYWW NNN 8-Lead MSOP XXXXXX YWWNNN Legend: XX...X Customer specific information* Y Year code (last digit of calendar year) YY Year code (last 2 digits of calendar year) WW Week code (week of January 1 is week ‘ ...
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... Mold Draft Angle Bottom * Controlling Parameter § Significant Characteristic Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side. JEDEC Equivalent: MS-001 Drawing No. C04-018 2003 Microchip Technology Inc. TC642B/TC647B ...
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... TC642B/TC647B 8-Lead Plastic Small Outline (SN) – Narrow, 150 mil (SOIC 45× c Dimension Limits Number of Pins Pitch Overall Height Molded Package Thickness Standoff § Overall Width Molded Package Width Overall Length Chamfer Distance Foot Length Foot Angle Lead Thickness ...
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... Mold Draft Angle Top Mold Draft Angle Bottom *Controlling Parameter Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MO-187 Drawing No. C04-111 2003 Microchip Technology Inc. TC642B/TC647B φ Units ...
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... TC642B/TC647B 6.2 Taping Form Component Taping Orientation for 8-Pin MSOP Devices PIN 1 Carrier Tape, Number of Components Per Reel and Reel Size: Package Carrier Width (W) 8-Pin MSOP 12 mm Component Taping Orientation for 8-Pin SOIC Devices PIN 1 Carrier Tape, Number of Components Per Reel and Reel Size: ...
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... Range Device: TC642B: PWM Fan Speed Controller with Mini- mum Fan Speed, Fan Restart, Fan Fault Detection, and Over-Temp Detection. TC647B: PWM Fan Speed Controller with Mini- mum Fan Speed, Fan Restart, and Fan Fault Detection. Temperature E = -40°C to +85°C ...
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... TC642B/TC647B NOTES: DS21756B-page 32 2003 Microchip Technology Inc. ...
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... QS-9000 compliant for its PICmicro 8-bit MCUs code hopping ® ® devices, Serial EEPROMs, microperipherals, non-volatile memory and analog products. In addition, Microchip’s quality system for the design and manufacture of development systems is ISO 9001 certified. 2003 Microchip Technology Inc ...
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... D-85737 Ismaning, Germany Tel: 49-89-627-144-0 Fax: 49-89-627-144-44 Italy Microchip Technology SRL Via Quasimodo, 12 20025 Legnano (MI) Milan, Italy Tel: 39-0331-742611 Fax: 39-0331-466781 United Kingdom Microchip Ltd. 505 Eskdale Road Winnersh Triangle Wokingham Berkshire, England RG41 5TU Tel: 44-118-921-5869 Fax: 44-118-921-5820 03/25/03 2003 Microchip Technology Inc. ...