M TC649 PWM Fan Speed Controller with Auto-Shutdown and FanSense™ Technology Features • Temperature Proportional Fan Speed for Acoustic Control and Longer Fan Life • Efficient PWM Fan Drive • 3.0V to 5.5V Supply Range: - Fan Voltage Independent of TC649 Supply Voltage - Supports any Fan Voltage • FanSense™ Fault Detection Circuits Protect Against Fan Failure and Aid System Testing • Automatic Shutdown Mode for “Green” Systems • Supports Low Cost NTC/PTC Thermistors • Space Saving 8-Pin MSOP Package Applications • • • • • • • Power Supplies Computers File Servers Portable Computers Telecom Equipment UPSs, Power Amps General Purpose Fan Speed Control Available Tools • Fan Controller Demonstration Board (TC642DEMO) • Fan Controller Evaluation Kit (TC642EV) Package Types SOIC/PDIP/MSOP VIN 1 CF 2 VAS GND 8 VDD 7 VOUT 3 6 FAULT 4 5 SENSE TC649 General Description The TC649 is a switch mode, fan speed controller for use with brushless DC fans. Temperature proportional speed control is accomplished using pulse width modulation (PWM). A thermistor (or other voltage output temperature sensor) connected to the VIN input furnishes the required control voltage of 1.25V to 2.65V (typical) for 0% to 100% PWM duty cycle. The TC649 automatically suspends fan operation when measured temperature (VIN) is below a user programmed minimum setting (VAS). An integrated Start-up Timer ensures reliable motor start-up at turn-on, coming out of shutdown mode, auto-shutdown mode or following a transient fault. In normal fan operation, a pulse train is present at SENSE (Pin 5). The TC649 features Microchip Technology’s proprietary FanSenseTM technology for increasing system reliability. A missing pulse detector monitors this pin during fan operation. A stalled, open or unconnected fan causes the TC649 to trigger its Start-up Timer once. If the fault persists, the FAULT output goes low, and the device is latched in its shutdown mode. See Section 5.0, “Typical Applications”, for more information and system design guidelines. The TC649 is available in the 8-pin PDIP, SOIC and MSOP packages and is available in the industrial and extended commercial temperature ranges. 2002 Microchip Technology Inc. DS21449C-page 1 TC649 Functional Block Diagram TC649 VIN – VDD PWM + Control Logic VOUT CF 3 x TPWM Timer Clock Generator – VAS Start-up Timer + FAULT SHDN Missing Pulse Detect – + – GND + VSHDN 10k SENSE 70mV (typ.) DS21449C-page 2 2002 Microchip Technology Inc. TC649 1.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings* Supply Voltage ......................................................... 6V Input Voltage, Any Pin.... (GND – 0.3V) to (VDD +0.3V) *Stresses above 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 above those indicated in the operation sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Package Thermal Resistance: PDIP (RθJA) ............................................ 125°C/W SOIC (RθJA) ............................................ 155°C/W MSOP (RθJA) .......................................... 200°C/W Specified Temperature Range ........... -40°C to +125°C Storage Temperature Range.............. -65°C to +150°C DC ELECTRICAL SPECIFICATIONS Electrical Characteristics: Unless otherwise specified, TMIN ≤ TA ≤ TMAX, VDD = 3.0V to 5.5V. Symbol Parameter Min Typ Max Units Test Conditions VDD Supply Voltage 3.0 — 5.5 V IDD Supply Current, Operating — 0.5 1.0 mA Pins 6, 7 Open, CF = 1 µF, VIN = VC(MAX) IDD(SHDN) Supply Current, Shutdown/ Auto-shutdown Mode — 25 — µA Pins 6, 7 Open; Note 1 CF =1 µF, VIN = 0.35V IIN VIN, VAS Input Leakage -1.0 — +1.0 µA VOUT Output tR VOUT Rise Time — — 50 µsec tF VOUT Fall Time — — 50 µsec IOH = 5 mA, Note 1 IOL = 1 mA, Note 1 tSHDN Pulse Width (On VIN ) to Clear Fault Mode 30 — — µsec VSHDN, VHYST Specifications, Note 1 IOL Sink Current at VOUT Output 1.0 — — mA VOL = 10% of VDD IOH Source Current at V OUT Output 5.0 — — mA VOH = 80% of VDD 50 70 90 mV Note 1 SENSE Input VTH(SENSE) SENSE Input threshold Voltage with Respect to GND FAULT Output VOL Output Low Voltage — — 0.3 V tMP Missing Pulse Detector Timer — 32/F — Sec IOL = 2.5 mA CF = 1.0 µF tSTART Start-up Timer — 32/F — Sec CF = 1.0 µF tDIAG Diagnostic Timer — 3/F — Sec CF = 1.0 µF VIN , VAS Inputs VC(MAX) Voltage at VIN for 100% Duty Cycle 2.5 2.65 2.8 V VC(SPAN) VC(MAX) - VC(MIN) 1.3 1.4 1.5 V VAS Auto-shutdown Threshold VC(MAX) -VC(SPAN) — VC(MAX) V VSHDN Voltage applied to VIN to Release Reset/Shutdown — — VDD x 0.13 V VREL Voltage applied to V IN to Release Reset Mode VDD x 0.19 — — V VHYST Hysteresis on V SHDN, VREL — 0.01 x VDD — V VHAS Hysteresis on Auto-shutdown Comparator — 70 — mV 26 30 34 Hz VDD = 5V, See Figure 5-11 Pulse Width Modulator FOSC PWM Frequency CF = 1.0 µF Note 1: Ensured by design, not tested. 2002 Microchip Technology Inc. DS21449C-page 3 TC649 2.0 PIN DESCRIPTIONS The descriptions of the pins are listed in Table 2-1. TABLE 2-1: Pin No. PIN FUNCTION TABLE Symbol Descriptiion 2.3 Analog Input (VAS) An external resistor divider connected to the VAS input sets the auto-shutdown threshold. Auto-shutdown occurs when V IN ≤ VAS. The fan is automatically restarted when VIN ≥ (VAS + VHAS). See Section 5.0, “Typical Applications”, for more details. 1 VIN Analog Input 2 CF Analog Output 2.4 3 VAS Analog Input GND denotes the ground terminal. 4 GND Ground Terminal 5 SENSE Analog Input 6 FAULT Digital (Open Collector) Output 7 VOUT Digital Output 8 VDD Power Supply Input 2.1 Analog Input (VIN) The thermistor network (or other temperature sensor) connects to the VIN input. A voltage range of 1.25V to 2.65V (typical) on this pin drives an active duty cycle of 0% to 100% on the VOUT pin. The TC649 enters shutdown mode when V IN ≤ VSHDN. During shutdown, the FAULT output is inactive, and supply current falls to 25 µA (typical). The TC649 exits shutdown mode when VIN ≥ VREL. See Section 5.0, “Typical Applications”, for details. 2.2 Analog Output (CF) CF is the positive terminal for the PWM ramp generator timing capacitor. The recommended CF is 1 µF for 30 Hz PWM operation. DS21449C-page 4 2.5 Ground (GND) Analog Input (SENSE) Pulses are detected at the SENSE pin as fan rotation chops the current through a sense resistor (RSENSE). The absence of pulses indicates a fault. See Section 5.0, “Typical Applications”, for more details. 2.6 Digital Output (FAULT) The FAULT line goes low to indicate a fault condition. When FAULT goes low due to a fan fault condition, the device is latched in shutdown mode until deliberately cleared or until power is cycled. 2.7 Digital Output (VOUT) VOUT is an active high complimentary output that drives the base of an external NPN transistor (via an appropriate base resistor) or the gate of an N-channel MOSFET. This output has asymmetrical drive (see Section 1.0, “Electrical Characteristics”). 2.8 Power Supply Input (VDD) VDD may be independent of the fan’s power supply (see Section 1.0, “Electrical Characteristics”). 2002 Microchip Technology Inc. TC649 3.0 DETAILED DESCRIPTION 3.5 3.1 PWM Pulses appearing at SENSE due to the PWM turning on are blanked, and the remaining pulses are filtered by a missing pulse detector. If consecutive pulses are not detected for thirty-two PWM cycles (≅1 Sec if CF = 1 µF), the Diagnostic Timer is activated, and VOUT is driven high continuously for three PWM cycles (≅100 msec if CF = 1 µF). If a pulse is not detected within this window, the Start-up Timer is triggered (see Section 3.3, “Start-up Timer”). This should clear a transient fault condition. If the missing pulse detector times out again, the PWM is stopped and FAULT goes low. When FAULT is activated due to this condition, the device is latched in shutdown mode and will remain off indefinitely. The TC649 is thus prevented from attempting to drive a fan under catastrophic fault conditions. The PWM circuit consists of a ramp generator and threshold detector. The frequency of the PWM is determined by the value of the capacitor connected to the C F input. A frequency of 30 Hz is recommended for most applications (CF = 1 µF). The PWM is also the time base for the Start-up Timer (see Section 3.3, “Start-up Timer”). The PWM voltage control range is 1.25V to 2.65V (typical) for 0% to 100% output duty cycle. 3.2 VOUT Output The V OUT pin is designed to drive a low cost transistor or MOSFET as the low side power switching element in the system. Various examples of driver circuits will be shown throughout the datasheet. This output has asymmetric complementary drive and is optimized for driving NPN transistors or N-channel MOSFETs. Since the system relies on PWM rather than linear control, the power dissipation in the power switch is kept to a minimum. Generally, very small devices (TO-92 or SOT packages) will suffice. 3.3 Start-Up Timer To ensure reliable fan start-up, the Start-up Timer turns the VOUT output on for 32 cycles of the PWM whenever the fan is started from the off state. This occurs at power-up and when coming out of shutdown or autoshutdown mode. If the PWM frequency is 30 Hz (CF = 1 µF) the resulting start-up time will be approximately one second. If a fan fault is detected (see Section 3.5, FAULT Output), the Diagnostic Timer is triggered once, followed by the Start-up Timer. If the fault persists, the device is shut down (see Section 3.5, FAULT Output). 3.4 FAULT Output One of two things will restore operation: Cycling power off and then on again; or pulling VIN below VSHDN and releasing it to a level above VREL. When one of these two conditions is satisfied, the normal start-up cycle is triggered and operation will resume, provided the fault has been cleared. 3.6 Auto-Shutdown Mode If the voltage on VIN becomes less than the voltage on VAS, the fan is automatically shut off (auto-shutdown mode). The TC649 exits auto-shutdown mode when the voltage on VIN becomes higher than the voltage on VAS by VHAS (the auto-shutdown hysteresis voltage, see Figure 3-1). The Start-up Timer is triggered and normal operation is resumed upon exiting auto-shutdown mode. The FAULT output is unconditionally inactive in auto-shutdown mode. SENSE Input (FanSense™ Technology) The SENSE input (Pin 5) is connected to a low value current sensing resistor in the ground return leg of the fan circuit. During normal fan operation, commutation occurs as each pole of the fan is energized. This causes brief interruptions in the fan current, seen as pulses across the sense resistor. If the device is not in shutdown or auto-shutdown mode, and pulses are not appearing at the SENSE input, a fault exists. The short, rapid change in fan current (high dl/dt) causes a corresponding dV/dt across the sense resistor, RSENSE. The waveform on R SENSE is differentiated and converted to a logic-level pulse-train by CSENSE and the internal signal processing circuitry. The presence and frequency of this pulse-train is a direct indication of fan operation. See Section 5.0, “Typical Applications”, for more details. 2002 Microchip Technology Inc. DS21449C-page 5 TC649 TC649 Status Normal Operation Auto-Shutdown Mode Normal Operation ShutDown Normal Operation HI 2.6V VAS + VHAS VAS TEMP. 1.2V tRESET VIN VREL VSHDN LO GND TIME FIGURE 3-1: 3.7 TC649 Nominal Operation. Shutdown Mode (RESET) If an unconditional shutdown and/or device reset is desired, the TC649 may be placed in shutdown mode by forcing VIN to a logic low (i.e., VIN < VSHDN) (see Figure 3-1). In this mode, all functions cease and the FAULT output is unconditionally inactive. The TC649 should not be shut down unless all heat producing activity in the system is at a negligible level. The TC649 exits shutdown mode when VIN becomes greater than VREL, the release voltage. Entering shutdown mode also performs a complete device reset. Shutdown mode resets the TC649 into its power-up state. The Start-up and Fault Timers and any current faults are cleared. FAULT is unconditionally inactive in shutdown mode. Upon exiting shutdown mode (VIN > VREL), the Start-up Timer will be triggered and normal operation will resume, assuming no fault conditions exist and VIN > (VAS + VHAS). Note: If VIN < VAS when the device exits shutdown mode, the fan will not restart, but will be in auto-shutdown mode. DS21449C-page 6 If a fan fault has occurred and the device has latched itself into shutdown mode, performing a reset will not clear the fault unless V IN > (VAS + VHAS). If V IN is not greater than VAS + VHAS upon exiting shutdown mode, the fan will not be restarted, and there will be no way to establish that the fan fault has been cleared. To ensure that a complete reset takes place, the user’s circuitry must ensure that VIN > (VAS + VHAS) when the device is released from shutdown mode. A recommended algorithm for management of the TC649 by a host microcontroller or other external circuitry is given in Section 5.0, “Typical Applications”. A small amount of hysteresis, typically one percent of VDD (50mV at VDD = 5.0V), is designed into the V SHDN/VREL threshold. The levels specified for VSHDN and VREL in Section 1.0, “Electrical Characteristics”, include this hysteresis plus adequate margin to account for normal variations in the absolute value of the threshold and hysteresis. CAUTION: The fan will remain off as long as the VIN pin is being held low or VIN < VAS+ VHAS. 2002 Microchip Technology Inc. TC649 4.0 SYSTEM BEHAVIOR The flowcharts describing the TC649’s behavioral algorithm are shown in Figure 4-1. They can be summarized as follows: 4.1 Power-Up (1) Assuming the device is not being held in shutdown or auto-shutdown mode (VIN > VAS)... (2) Turn VOUT output on for 32 cycles of the PWM clock. This ensures that the fan will start from a dead stop. 4.3 Fan Fault Fan Fault is an infinite loop wherein the TC649 is latched in shutdown mode. This mode can only be released by a reset (i.e., VIN being brought below VSHDN, then above (VAS + VHAS) or by power-cycling). (1) While in this state, FAULT is latched on (low) and the VOUT output is disabled. (2) A reset sequence applied to the VIN pin will exit the loop to Power-up. (3) End. (3) During this Start-up Timer, if a fan pulse is detected, branch to Normal Operation; if none are received… (4) Activate the 32-cycle Start-up Timer one more time and look for fan pulse; if a fan pulse is detected, proceed to Normal Operation; if none are received… (5) Proceed to Fan Fault. (6) End. 4.2 Normal Operation Normal Operation is an endless loop which may only be exited by entering shutdown mode, auto-shutdown mode or Fan Fault. The loop can be thought of as executing at the frequency of the oscillator and PWM. (1) Reset the missing pulse detector. (2) Is TC649 in shutdown or auto-shutdown mode? If so… a. V OUT duty cycle goes to zero. b. FAULT is disabled. c. Exit the loop and wait for VIN > (VAS + VHAS) to resume operation. (3) Drive VOUT to a duty cycle proportional to VIN on a cycle by cycle basis. (4) If a fan pulse is detected, branch back to the start of the loop (1). (5) If the missing pulse detector times out … (6) Activate the 3-cycle Diagnostic Timer and look for pulses; if a fan pulse is detected, branch back to the start of the loop (1); if none are received… (7) Activate the 32-cycle Start-up Timer and look for pulses; if a fan pulse is detected, branch back to the start of the loop (1); if none are received… (8) Quit Normal Operation and go to Fan Fault. (9) End. 2002 Microchip Technology Inc. DS21449C-page 7 TC649 Normal Operation Power-Up Clear Missing Pulse Detector Power-on Reset FAULT = 1 Yes Shutdown VOUT = 0 VIN < VSHDN Yes No VIN > VREL? VIN < VSHDN? No No VIN > VREL No Yes Yes AutoShutdown VOUT = 0 Yes VIN < VAS? VIN < VAS? No VIN > No (VAS + VHAS) Fire Start-up Timer (1 SEC) Yes Fan Pulse Detected? Fan Pulse Detected? Hot Start No No Yes Fire Diagnostic Timer (100msec) Yes Fan Pulse Detected? Yes Normal Operation Power-Up Yes M.P.D. Expired? Fire Start-up Timer YES (1 SEC) Yes Yes VOUT Proportional to VIN Yes No Auto Shutdown VOUT = 0 No VIN > (VAS + VHAS) No Hot Start Shutdown VOUT = 0 No No Fan Pulse Detected? Fire Start-up Timer (1 Sec) Fan Fault Yes Fan Pulse Detected? No Fan Fault Fan Fault FAULT = 0, VOUT = 0 No Auto-Shutdown FAULT = 1, VOUT = 0 VIN < VSHDN? Yes Yes No VIN > VREL? No No Cycling Power Yes VIN > (VAS + VHAS)? Yes Power-Up FIGURE 4-1: DS21449C-page 8 TC649 Behavioral Algorithm Flowchart. 2002 Microchip Technology Inc. TC649 5.0 TYPICAL APPLICATIONS The TC642 demonstration and prototyping board (TC642DEMO) and the TC642 Evaluation Kit (TC642EV) provide working examples of TC649 circuits 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 design using the TC649 should consult the documentation for both TC642EV (DS21403) and TC642DEMO (DS21401).Figure 5-1 shows the base schematic for the TC642DEMO. Designing with the TC649 involves the following: (1) The temperature sensor network must be configured to deliver 1.25V to 2.65V on V IN for 0% to 100% of the temperature range to be regulated. (2) The auto-shutdown temperature must be set with a voltage divider on VAS. (3) The output drive transistor and associated circuitry must be selected. (4) The SENSE network, RSENSE and CSENSE, must be designed for maximum efficiency while delivering adequate signal amplitude. (5) If shutdown capability is desired, the drive requirements of the external signal or circuit must be considered. +5V* +C +12V B 1 µF R1 NTC Fan Shutdown** CB 0.01 µF R2 VIN VDD FAULT +5V Fan Fault Shutdown Q1 RBASE TC649 VOUT R3 VAS CB 0.01 µF SENSE CSENSE CF R4 CF GND RSENSE 1 µF Notes: *See cautions regarding Latch-up Considerations in Section 5.0, "Typical Applications". **Optional. See Section 5.0, "Typical Applications" for details. FIGURE 5-1: Typical Application Circuit. 2002 Microchip Technology Inc. DS21449C-page 9 TC649 5.1 Temperature Sensor Design EQUATION The temperature signal connected to VIN must output a voltage in the range of 1.25V to 2.65V (typical) for 0% to 100% of the temperature range of interest. The circuit in Figure 5-2 illustrates a convenient way to provide this signal. VDD x R2 RTEMP (T1) + R2 VDD x R2 RTEMP (T2) + R2 IDIV R1 =100 kΩ VIN R2 = 23.2 kΩ FIGURE 5-2: Circuit. Temperature Sensing Figure 5-2 shows a simple temperature dependent voltage divider circuit. RT1 is a conventional NTC thermistor, while R 1 and R2 are standard resistors. The supply voltage, VDD, is divided between R2 and the parallel combination of RT1 and R1. For convenience, the parallel combination of RT1 and R1 will be referred to as RTEMP. The resistance of the thermistor at various temperatures is obtained from the manufacturer’s specifications. Thermistors are often referred to in terms of their resistance at 25°C. Generally, the thermistor shown in Figure 5-2 is a nonlinear device with a negative temperature coefficient (also called an NTC thermistor). In Figure 5-2, R 1 is used to linearize the thermistor temperature response and R2 is used to produce a positive temperature coefficient at the VIN node. As an added benefit, this configuration produces an output voltage delta of 1.4V, which is well within the range of the V C(SPAN) specification of the TC649. A 100 kΩ NTC thermistor is selected for this application in order to keep IDIV at a minimum. For the voltage range at VIN to be equal to 1.25V to 2.65V, the temperature range of this configuration is 0°C to 50°C. If a different temperature range is required from this circuit, R 1 should be chosen to equal the resistance value of the thermistor at the center of this new temperature range. It is suggested that a maximum temperature range of 50°C be used with this circuit due to thermistor linearity limitations. With this change, R2 is adjusted according to the following equations: DS21449C-page 10 = V(T2) Where T1 and T2 define the temperature range of the circuit. RTEMP is the parallel equivalent of the thermistor and R1 at those temperatures. VDD RT1 NTC Thermistor 100 kΩ @ 25˚C = V(T1) More information about thermistors may be obtained from AN679, “Temperature Sensing Technologies”, and AN685, “Thermistors in Single Supply Temperature Sensing Circuit”, which can be downloaded from Microchip’s website at www.microchip.com. 5.2 Auto-Shutdown Temperature Design A voltage divider on VAS sets the temperature at which the part is automatically shut down if the sensed temperature at VIN drops below the set temperature at VAS (i.e. V IN < VAS). As with the VIN input, 1.25V to 2.65V (typ.) corresponds to the temperature range of interest from T1 to T2, respectively. Assuming that the temperature sensor network designed above is linearly related to temperature, the shutdown temperature TAS is related to T2 and T1 by: EQUATION 2.65V - 1.25V T2 - T1 VAS = ( 1.4V T2 - T1 = VAS - 1.25 TAS - T1 ) (TAS - T1) + 1.25 For example, if 1.25V and 2.65V at VIN corresponds to a temperature range of T1 = 0°C to T2 = 125°C, and the auto-shutdown temperature desired is 25°C, then VAS voltage is: EQUATION VAS = 1.4V (125 - 0) (25 - 0) + 1.25 = 1.53V The VAS voltage may be set using a simple resistor divider, as is shown in Figure 5-3. 2002 Microchip Technology Inc. TC649 5.3 VDD R1 IDIV One boundary condition which may impact the selection of the minimum fan speed is the irregular activation of the Diagnostic Timer due to the TC649 “missing” fan commutation pulses at low speeds. This is a natural consequence of low PWM duty cycles (typically 25% or less). Recall that the SENSE function detects commutation of the fan as disturbances in the current through RSENSE. These can only occur when the fan is energized (i.e., VOUT is “on”). At very low duty cycles, the VOUT output is “off” most of the time. The fan may be rotating normally, but the commutation events are occurring during the PWM’s off-time. IIN VAS R2 GND FIGURE 5-3: VAS Circuit. Per Section 1.0, “Electrical Characteristics”, the leakage current at the VAS pin is no more than 1 µA. It is conservative to design for a divider current, IDIV, of 100 µA. If VDD = 5.0V then: EQUATION 5.0V IDIV = 1e– 4A R1 + R2 5.0V R1 + R2 = 1e–4A , therefore = 50,000Ω = 50 kΩ We can further specify R1 and R 2 by the condition that the divider voltage is equal to our desired VAS. This yields the following: EQUATION VAS = VDD x R 2 R1 + R2 Solving for the relationship between R1 and R 2 results in: EQUATION R1 = R2 x VDD - VAS VAS = R2 x Operations at Low Duty Cycle 5 -1.53 1.53 In the case of this example, R 1 = (2.27) R 2. Substituting this relationship back into the VAS equation above yields the resistor values: The phase relationship between the fan’s commutation and the PWM edges tends to “walk around” as the system operates. At certain points, the TC649 may fail to capture a pulse within the 32-cycle missing pulse detector window. If this happens, the 3-cycle Diagnostic Timer will be activated, the VOUT output will be active continuously for three cycles and, if the fan is operating normally, a pulse will be detected. If all is well, the system will return to normal operation. There is no harm in this behavior, but it may be audible to the user as the fan accelerates briefly when the Diagnostic Timer fires. For this reason, it is recommended that VAS be set no lower than 1.8V. 5.4 FanSense™ Network (RSENSE and CSENSE) The FanSense network, comprised of RSENSE and CSENSE, allows the TC649 to detect commutation of the fan motor (FanSense™ technology). This network can be thought of as a differentiator and threshold detector. The function of R SENSE is to convert the fan current into a voltage. CSENSE serves to AC-couple this voltage signal and provide a ground-referenced input to the SENSE pin. Designing a proper SENSE network is simply a matter of scaling RSENSE to provide the necessary amount of gain (i.e., the current-to-voltage conversion ratio). A 0.1 µF ceramic capacitor is recommended for CSENSE. Smaller values require larger sense resistors, and higher value capacitors are bulkier and more expensive. Using a 0.1 µF capacitor results in reasonable values for RSENSE. Figure 5-4 illustrates a typical SENSE network. Figure 5-5 shows the waveforms observed using a typical SENSE network. R2 = 15.3 kΩ, and R1 = 34.7 kΩ In this case, the standard values of 34.8 kΩ and 15.4 kΩ are very close to the calculated values and would be more than adequate. 2002 Microchip Technology Inc. DS21449C-page 11 TC649 RSENSE VS. FAN CURRENT TABLE 5-1: VDD Nominal Fan Current (mA) RSENSE (Ω) Fan RBASE VOUT Q1 SENSE CSENSE (0.1 µF Typ.) RSENSE 5.5 GND FIGURE 5-4: SENSE Network. Tek Run: 10.0kS/s Sample [ T ] Waveform @ Sense Resistor GND 1 Waveform @ Sense Pin 90mV 50mV GND T 2 Ch1 100mV Ch2 FIGURE 5-5: 100mV M5.00ms Ch1 142mV SENSE Waveforms. Table 5-1 lists the recommended values of RSENSE based on the nominal operating current of the fan. Note that the current draw specified by the fan manufacturer may be a worst-case rating for near-stall conditions and may not be the fan’s nominal operating current. The values in Table 5-1 refer to actual average operating current. If the fan current falls between two of the values listed, use the higher resistor value. The end result of employing Table 5-1 is that the signal developed across the sense resistor is approximately 450 mV in amplitude. DS21449C-page 12 50 9.1 100 4.7 150 3.0 200 2.4 250 2.0 300 1.8 350 1.5 400 1.3 450 1.2 500 1.0 Output Drive Transistor Selection The TC649 is designed to drive an external transistor or MOSFET for modulating power to the fan. This is shown as Q1 in Figures 5-1, 5-4, 5-6, 5-7, 5-8 and 5-9. The VOUT pin has a minimum source current of 5 mA and a minimum sink current of 1 mA. Bipolar transistors or MOSFETs may be used as the power switching element as shown in Figure 5-6. When high current gain is needed to drive larger fans, two transistors may be used in a Darlington configuration. These circuit topologies are shown in Figure 5-6: (a) shows a single NPN transistor used as the switching element; (b) illustrates the Darlington pair; and (c) shows an Nchannel MOSFET. One major advantage of the TC649’s PWM control scheme versus linear speed control is that the power dissipation in the pass element is kept very low. Generally, low cost devices in very small packages, such as TO-92 or SOT, can be used effectively. For fans with nominal operating currents of no more than 200 mA, a single transistor usually suffices. Above 200 mA, the Darlington or MOSFET solution is recommended. For the fan sensing function to work correctly, it is imperative that the pass transistor be fully saturated when “on”. 2002 Microchip Technology Inc. TC649 be enough to saturate the transistor when conducting the full fan current (transistor must have sufficient gain); (3) the VOUT voltage must be high enough to sufficiently drive the gate of the MOSFET to minimize the RDS(on) of the device; (4) rated fan current draw must be within the transistor's/MOSFET's current handling capability; and (5) power dissipation must be kept within the limits of the chosen device. Table 5-2 gives examples of some commonly available transistors and MOSFETs. This table should be used as a guide only since there are many transistors and MOSFETs which will work just as well as those listed. The critical issues when choosing a device to use as Q1 are: (1) the breakdown voltage (V(BR)CEO or VDS (MOSFET)) must be large enough to withstand the highest voltage applied to the fan (Note: This will occur when the fan is off); (2) 5 mA of base drive current must VDD VDD VDD Fan Fan Fan RBASE VOUT VOUT Q1 RBASE Q1 Q1 VOUT Q2 RSENSE GND TABLE 5-2: Device MMBT2222A MPS2222A MPS6602 GND GND a) Single Bipolar Transistor FIGURE 5-6: RSENSE RSENSE C) N-Channel MOSFET b) Darlington Transistor Pair Output Drive Transistor Circuit Topologies. TRANSISTORS AND MOSFETS FOR Q1 (VDD = 5V) Package Max. V BE(sat)/VGS (V) Min. HFE VCEO/VDS (V) Fan Current (mA) Suggested RBASE (Ω) SOT-23 1.2 50 40 150 800 TO-92 1.2 50 40 150 800 TO-92 1.2 50 40 500 301 SI2302 SOT-23 2.5 NA 20 500 Note 1 MGSF1N02E SOT-23 2.5 NA 20 500 Note 1 SI4410 SO-8 4.5 NA 30 1000 Note 1 SI2308 SOT-23 4.5 NA 60 500 Note 1 Note 1: A series gate resistor may be used in order to control the MOSFET turn-on and turn-off times. 2002 Microchip Technology Inc. DS21449C-page 13 TC649 A base-current limiting resistor is required with bipolar transistors (Figure 5-7). The correct value for this resistor can be determined as follows: VOH VRSENSE = VRSENSE + VBE(SAT) + VRBASE = IFAN x RSENSE VRBASE = RBASE x IBASE IBASE = IFAN / hFE VDD Fan VOH is specified as 80% of VDD in Section 1.0, “Electrical Characteristics”; VBE(SAT) is given in the chosen transistor data sheet. It is now possible to solve for RBASE. RBASE VOH = 80% VDD +V RBASE VBE(SAT)– EQUATION RBASE = Q1 – + + VRSENSE VOH - V BE(SAT) - VRSENSE IBASE RSENSE – Some applications benefit from the fan being powered from a negative supply to keep motor noise out of the positive supply rails. This can be accomplished as shown in Figure 5-8, with zener diode D1 offsetting the -12V power supply voltage, holding transistor Q1 off when VOUT is low. When VOUT is high, the voltage at the anode of D1 increases by VOUT, causing Q1 to turn on. Operation is otherwise the same as in the case of fan operation from +12V. GND FIGURE 5-7: R BASE. Circuit For Determining +5V VDD R2* 2.2 kΩ VOUT D1 12.0V Zener FAN TC649 Q1* GND R4* 10 kΩ R3* 2.2 Ω -12V Note: * Value depends on the specific application and is shown for example only. See Section 5.0, "Typical Applications", for more details. FIGURE 5-8: DS21449C-page 14 Powering the Fan from a -12V Supply. 2002 Microchip Technology Inc. TC649 5.6 Latch-up Considerations a high impedance source (such as a thermistor). Additionally, the VDD input should be bypassed with a 1 µF capacitor with grounds being kept as short as possible. To keep fan noise off the TC649 ground pin, individual ground returns for the TC649 and the low side of the fan current sense resistor should be used. As with any CMOS IC, the potential exists for latch-up if signals are applied to the device which are outside the power supply range. This is of particular concern during power-up if the external circuitry (such as the sensor network, VAS divider or shutdown circuit) are powered by a supply different from that of the TC649. Care should be taken to ensure that the TC649’s VDD supply powers up first. If possible, the networks attached to VIN and VAS should connect to the VDD supply at the same physical location as the IC itself. Even if the IC and any external networks are powered by the same supply, physical separation of the connecting points can result in enough parasitic capacitance and/ or inductance in the power supply connections to delay one power supply “routing” versus another. 5.7 Design Example Step 1. Calculate R1 and R2 based on using an NTC having a resistance of 10 kΩ at TMIN (25°C) and 4.65 kΩ at TMAX (45°C) (see Figure 5-9). R1 = 20.5 kΩ R2 = 3.83 kΩ Step 2. Set auto-shutdown Level. VAS = 1.8V. Limit the divider current to 100 µA R5 = 33 kΩ R6 = 18 kΩ Power Supply Routing and Bypassing Step 3. Design the output circuit. Noise present on the VIN and VAS inputs may cause erroneous operation of the FAULT output. As a result, these inputs should be bypassed with a 0.01 µF capacitor mounted as close to the package as possible. This is especially true of VIN, which is usually drive from Maximum fan motor current = 250 mA. Q1 beta is chosen at 50 from which R7 = 800 Ω. +5V OpenDrain Device R1 20.5 kΩ R2 3.83 kΩ (Optional) NTC 10 kΩ @ 25˚C 1 RESET Shutdown CB 1 µF VIN +12V +5V 8 4 VDD GND CB 0.01 µF Fan FAULT 6 R7 800 Ω +5V TC649 VOUT R5 33 kΩ R6 18 kΩ 3 VAS CB 0.01 µF 2 CF Q1 Fan Fault SENSE 7 5 CSENSE 0.1 µF RSENSE 2.2 Ω C1 1 µF FIGURE 5-9: Design Example. 2002 Microchip Technology Inc. DS21449C-page 15 TC649 5.8 TC649 as a Microcontroller Peripheral In a system containing a microcontroller or other host intelligence, the TC649 can be effectively managed as a CPU peripheral. Routine fan control functions can be performed by the TC649 without processor intervention. The microcontroller receives temperature data from one or more points throughout the system. It calculates a fan operating speed based on an algorithm specifically designed for the application at hand. The processor controls fan speed using complementary port bits I/O1 through I/O3. Resistors R1 through R6 (5% tolerance) form a crude 3-bit DAC that translates this 3-bit code from the processor's outputs into a 1.6V DC control signal. A monolithic DAC or digital pot may be used instead of the circuit shown in Figure 5-10. With VAS set at 1.8V, the TC649 enters auto-shutdown when the processor's output code is 000[B]. 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 TC649 following detection of a fault condition. The FAULT output can be connected to the processor's interrupt input or to another I/O pin for polled operation. . +12V +5V Analog or Digital Temperature Data from One or more Sensors (RESET) (Optional) Open-Drain I/O0 Output R1 110 kΩ (MSB) 1 I/O1 CB R2 CMOS 240 kΩ .01 µF 2 Outputs I/O2 R3 + 360 kΩ R7 1µF R4 I/O3 18 kΩ 33 kΩ 3 CMOS (LSB) R5 CB 1.5 kΩ Microcontroller +5V R8 +5V .01µF 18 kΩ 4 R6 1 kΩ +5V VIN VDD VOUT CF 8 7 TC649 VAS FAULT GND SENSE 6 5 Fan CB 1 µF R9 800 Ω 2N2222A +5V R10 10 kΩ 0.1 µF R11 2.2 Ω GND FIGURE 5-10: INT TC649 as a Microcontroller Peripheral. VRELEASE vs. Temperature 1.0 VDD = 5.5V VRELEASE (V) 0.9 VDD = 5.0V 0.8 0.7 VDD = 4.0V 0.6 VDD = 3.0V 0.5 0.4 0˚C 25˚C 85˚C TEMPERATURE FIGURE 5-11: DS21449C-page 16 VRELEASE vs. Temperature. 2002 Microchip Technology Inc. TC649 6.0 PACKAGING INFORMATION 6.1 Package Marking Information 8-Lead PDIP (300 mil) XXXXXXXX NNN YYWW TC649VPA 025 0215 8-Lead SOIC (150 mil) Example: 8-Lead MSOP TC649E XXXXXX YWWNNN Note: * XX...X YY WW NNN Example: TC649VOA 0215 025 XXXXXXXX YYWW NNN Legend: Example: 215025 Customer specific information* Year code (last 2 digits of calendar year) Week code (week of January 1 is week ‘01’) Alphanumeric traceability code In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line thus limiting the number of available characters for customer specific information. 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. DS21449C-page 17 TC649 8-Lead Plastic Dual In-line (P) – 300 mil (PDIP) E1 D 2 n 1 α E A2 A L c A1 β B1 p eB B Units Dimension Limits n p 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 Lower Lead Width Overall Row Spacing Mold Draft Angle Top Mold Draft Angle Bottom * Controlling Parameter § Significant Characteristic A A2 A1 E E1 D L c § B1 B eB α β MIN .140 .115 .015 .300 .240 .360 .125 .008 .045 .014 .310 5 5 INCHES* NOM MAX 8 .100 .155 .130 .170 .145 .313 .250 .373 .130 .012 .058 .018 .370 10 10 .325 .260 .385 .135 .015 .070 .022 .430 15 15 MILLIMETERS NOM 8 2.54 3.56 3.94 2.92 3.30 0.38 7.62 7.94 6.10 6.35 9.14 9.46 3.18 3.30 0.20 0.29 1.14 1.46 0.36 0.46 7.87 9.40 5 10 5 10 MIN MAX 4.32 3.68 8.26 6.60 9.78 3.43 0.38 1.78 0.56 10.92 15 15 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 DS21449C-page 18 2002 Microchip Technology Inc. TC649 8-Lead Plastic Small Outline (SN) – Narrow, 150 mil (SOIC) E E1 p D 2 B n 1 h α 45× c A2 A f β L Units Dimension Limits n p 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 Lead Width Mold Draft Angle Top Mold Draft Angle Bottom * Controlling Parameter § Significant Characteristic A A2 A1 E E1 D h L f c B α β MIN .053 .052 .004 .228 .146 .189 .010 .019 0 .008 .013 0 0 A1 INCHES* NOM 8 .050 .061 .056 .007 .237 .154 .193 .015 .025 4 .009 .017 12 12 MAX .069 .061 .010 .244 .157 .197 .020 .030 8 .010 .020 15 15 MILLIMETERS NOM 8 1.27 1.35 1.55 1.32 1.42 0.10 0.18 5.79 6.02 3.71 3.91 4.80 4.90 0.25 0.38 0.48 0.62 0 4 0.20 0.23 0.33 0.42 0 12 0 12 MIN MAX 1.75 1.55 0.25 6.20 3.99 5.00 0.51 0.76 8 0.25 0.51 15 15 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-012 Drawing No. C04-057 2002 Microchip Technology Inc. DS21449C-page 19 TC649 8-Lead Plastic Micro Small Outline Package (MS) (MSOP) E p E1 D 2 B n 1 α A2 A c φ A1 (F) L β Units Number of Pins Pitch Dimension Limits n p Overall Height NOM MAX 8 0.65 .026 A .044 .030 Standoff A1 .002 E .184 Molded Package Width MIN 8 A2 Overall Width MAX NOM Molded Package Thickness § MILLIMETERS* INCHES MIN 1.18 .038 0.76 .006 0.05 .193 .200 .034 0.86 0.97 4.67 4.90 .5.08 0.15 E1 .114 .118 .122 2.90 3.00 3.10 Overall Length D .114 .118 .122 2.90 3.00 3.10 Foot Length L .016 .022 .028 0.40 0.55 0.70 Footprint (Reference) .035 .037 .039 0.90 0.95 1.00 Foot Angle F φ 6 0 Lead Thickness c .004 .006 .008 0.10 0.15 0.20 Lead Width B α .010 .012 .016 0.25 0.30 0.40 Mold Draft Angle Top Mold Draft Angle Bottom β 0 6 7 7 7 7 *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. Drawing No. C04-111 DS21449C-page 20 2002 Microchip Technology Inc. TC649 6.2 Taping Form Component Taping Orientation for 8-Pin SOIC (Narrow) Devices User Direction of Feed PIN 1 W P Standard Reel Component Orientation for TR Suffix Device Carrier Tape, Number of Components Per Reel and Reel Size Package 8-Pin SOIC (N) Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size 12 mm 8 mm 2500 13 in Component Taping Orientation for 8-Pin MSOP Devices User Direction of Feed PIN 1 W P Standard Reel Component Orientation for TR Suffix Device Carrier Tape, Number of Components Per Reel and Reel Size Package 8-Pin MSOP 2002 Microchip Technology Inc. Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size 12 mm 8 mm 2500 13 in DS21449C-page 21 TC649 NOTES: DS21449C-page 22 2002 Microchip Technology Inc. TC649 ON-LINE SUPPORT Microchip provides on-line support on the Microchip World Wide Web site. The web site is used by Microchip as a means to make files and information easily available to customers. To view the site, the user must have access to the Internet and a web browser, such as Netscape® or Microsoft® Internet Explorer. Files are also available for FTP download from our FTP site. Connecting to the Microchip Internet Web Site The Microchip web site is available at the following URL: www.microchip.com SYSTEMS INFORMATION AND UPGRADE HOT LINE The Systems Information and Upgrade Line provides system users a listing of the latest versions of all of Microchip's development systems software products. Plus, this line provides information on how customers can receive the most current upgrade kits.The Hot Line Numbers are: 1-800-755-2345 for U.S. and most of Canada, and 1-480-792-7302 for the rest of the world. 092002 The file transfer site is available by using an FTP service to connect to: ftp://ftp.microchip.com The web site and file transfer site provide a variety of services. Users may download files for the latest Development Tools, Data Sheets, Application Notes, User's Guides, Articles and Sample Programs. A variety of Microchip specific business information is also available, including listings of Microchip sales offices, distributors and factory representatives. Other data available for consideration is: • Latest Microchip Press Releases • Technical Support Section with Frequently Asked Questions • Design Tips • Device Errata • Job Postings • Microchip Consultant Program Member Listing • Links to other useful web sites related to Microchip Products • Conferences for products, Development Systems, technical information and more • Listing of seminars and events 2002 Microchip Technology Inc. DS21449C-page23 TC649 READER RESPONSE It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150. Please list the following information, and use this outline to provide us with your comments about this document. To: Technical Publications Manager RE: Reader Response Total Pages Sent ________ From: Name Company Address City / State / ZIP / Country Telephone: (_______) _________ - _________ FAX: (______) _________ - _________ Application (optional): Would you like a reply? Device: TC649 Y N Literature Number: DS21449C Questions: 1. What are the best features of this document? 2. How does this document meet your hardware and software development needs? 3. Do you find the organization of this document easy to follow? If not, why? 4. What additions to the document do you think would enhance the structure and subject? 5. What deletions from the document could be made without affecting the overall usefulness? 6. Is there any incorrect or misleading information (what and where)? 7. How would you improve this document? DS21449C-page24 2002 Microchip Technology Inc. TC649 PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO. Device X /XX Temperature Range Package Device: TC649: PWM Fan Speed Controller w/Auto Shutdown and Fault Detection Temperature Range: V E Package: PA = Plastic DIP (300 mil Body), 8-lead * OA = Plastic SOIC, (150 mil Body), 8-lead UA = Plastic Micro Small Outline (MSOP), 8-lead Examples: a) TC649VOA: PWM Fan Speed Controller w/ Auto-Shutdown and Fault Detection, SOIC package. b) TC649VUA: PWM Fan Speed Controller w/ Auto-Shutdown and Fault Detection, MSOP package c) TC649VPA: PWM Fan Speed Controller w/ Auto-Shutdown and Fault Detection, PDIP package. d) TC649EOATR: PWM Fan Speed Controller w/ Auto-Shutdown and Fault Detection, SOIC package, Tape and Reel. = 0°C to +85°C = -40°C to +85°C * PDIP package is only offered in the V temp range. Sales and Support Data Sheets Products supported by a preliminary Data Sheet may have an errata sheet describing minor operational differences and recommended workarounds. To determine if an errata sheet exists for a particular device, please contact one of the following: 1. 2. 3. Your local Microchip sales office The Microchip Corporate Literature Center U.S. FAX: (480) 792-7277 The Microchip Worldwide Site (www.microchip.com) Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using. New Customer Notification System Register on our web site (www.microchip.com/cn) to receive the most current information on our products. 2002 Microchip Technology Inc. DS21449C-page25 TC649 NOTES: DS21449C-page 26 2002 Microchip Technology Inc. Information contained in this publication regarding device applications and the like is intended through suggestion only and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. No representation or warranty is given and no liability is assumed by 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 components in life support systems is not authorized except with express written approval by Microchip. No licenses are conveyed, implicitly or otherwise, under any intellectual property rights. Trademarks The Microchip name and logo, the Microchip logo, K EELOQ, MPLAB, PIC, PICmicro, PICSTART and PRO MATE are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. FilterLab, microID, MXDEV, MXLAB, PICMASTER, SEEVAL and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. dsPIC, dsPICDEM.net, ECONOMONITOR, FanSense, FlexROM, fuzzyLAB, In-Circuit Serial Programming, ICSP, ICEPIC, microPort, Migratable Memory, MPASM, MPLIB, MPLINK, MPSIM, PICC, PICDEM, PICDEM.net, rfPIC, Select Mode and Total Endurance are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. Serialized Quick Turn Programming (SQTP) is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. © 2002, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. Microchip received QS-9000 quality system certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona in July 1999 and Mountain View, California in March 2002. The Company’s quality system processes and procedures are QS-9000 compliant for its PICmicro® 8-bit MCUs, KEELOQ® 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. 2002 Microchip Technology Inc. DS21449C - page 27 M WORLDWIDE SALES AND SERVICE AMERICAS ASIA/PACIFIC Corporate Office Australia 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7200 Fax: 480-792-7277 Technical Support: 480-792-7627 Web Address: http://www.microchip.com Microchip Technology Australia Pty Ltd Suite 22, 41 Rawson Street Epping 2121, NSW Australia Tel: 61-2-9868-6733 Fax: 61-2-9868-6755 Rocky Mountain China - Beijing 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7966 Fax: 480-792-4338 Microchip Technology Consulting (Shanghai) Co., Ltd., Beijing Liaison Office Unit 915 Bei Hai Wan Tai Bldg. No. 6 Chaoyangmen Beidajie Beijing, 100027, No. China Tel: 86-10-85282100 Fax: 86-10-85282104 Atlanta 500 Sugar Mill Road, Suite 200B Atlanta, GA 30350 Tel: 770-640-0034 Fax: 770-640-0307 Boston 2 Lan Drive, Suite 120 Westford, MA 01886 Tel: 978-692-3848 Fax: 978-692-3821 Chicago 333 Pierce Road, Suite 180 Itasca, IL 60143 Tel: 630-285-0071 Fax: 630-285-0075 Dallas 4570 Westgrove Drive, Suite 160 Addison, TX 75001 Tel: 972-818-7423 Fax: 972-818-2924 Detroit Tri-Atria Office Building 32255 Northwestern Highway, Suite 190 Farmington Hills, MI 48334 Tel: 248-538-2250 Fax: 248-538-2260 Kokomo 2767 S. Albright Road Kokomo, Indiana 46902 Tel: 765-864-8360 Fax: 765-864-8387 Los Angeles 18201 Von Karman, Suite 1090 Irvine, CA 92612 Tel: 949-263-1888 Fax: 949-263-1338 China - Chengdu Microchip Technology Consulting (Shanghai) Co., Ltd., Chengdu Liaison Office Rm. 2401, 24th Floor, Ming Xing Financial Tower No. 88 TIDU Street Chengdu 610016, China Tel: 86-28-86766200 Fax: 86-28-86766599 China - Fuzhou Microchip Technology Consulting (Shanghai) Co., Ltd., Fuzhou Liaison Office Unit 28F, World Trade Plaza No. 71 Wusi Road Fuzhou 350001, China Tel: 86-591-7503506 Fax: 86-591-7503521 China - Shanghai Microchip Technology Consulting (Shanghai) Co., Ltd. Room 701, Bldg. B Far East International Plaza No. 317 Xian Xia Road Shanghai, 200051 Tel: 86-21-6275-5700 Fax: 86-21-6275-5060 China - Shenzhen 150 Motor Parkway, Suite 202 Hauppauge, NY 11788 Tel: 631-273-5305 Fax: 631-273-5335 Microchip Technology Consulting (Shanghai) Co., Ltd., Shenzhen Liaison Office Rm. 1315, 13/F, Shenzhen Kerry Centre, Renminnan Lu Shenzhen 518001, China Tel: 86-755-2350361 Fax: 86-755-2366086 San Jose China - Hong Kong SAR Microchip Technology Inc. 2107 North First Street, Suite 590 San Jose, CA 95131 Tel: 408-436-7950 Fax: 408-436-7955 Microchip Technology Hongkong Ltd. Unit 901-6, Tower 2, Metroplaza 223 Hing Fong Road Kwai Fong, N.T., Hong Kong Tel: 852-2401-1200 Fax: 852-2401-3431 New York Toronto 6285 Northam Drive, Suite 108 Mississauga, Ontario L4V 1X5, Canada Tel: 905-673-0699 Fax: 905-673-6509 India Microchip Technology Inc. India Liaison Office Divyasree Chambers 1 Floor, Wing A (A3/A4) No. 11, O’Shaugnessey Road Bangalore, 560 025, India Tel: 91-80-2290061 Fax: 91-80-2290062 Japan Microchip Technology Japan K.K. Benex S-1 6F 3-18-20, Shinyokohama Kohoku-Ku, Yokohama-shi Kanagawa, 222-0033, Japan Tel: 81-45-471- 6166 Fax: 81-45-471-6122 Korea Microchip Technology Korea 168-1, Youngbo Bldg. 3 Floor Samsung-Dong, Kangnam-Ku Seoul, Korea 135-882 Tel: 82-2-554-7200 Fax: 82-2-558-5934 Singapore Microchip Technology Singapore Pte Ltd. 200 Middle Road #07-02 Prime Centre Singapore, 188980 Tel: 65-6334-8870 Fax: 65-6334-8850 Taiwan Microchip Technology (Barbados) Inc., Taiwan Branch 11F-3, No. 207 Tung Hua North Road Taipei, 105, Taiwan Tel: 886-2-2717-7175 Fax: 886-2-2545-0139 EUROPE Austria Microchip Technology Austria GmbH Durisolstrasse 2 A-4600 Wels Austria Tel: 43-7242-2244-399 Fax: 43-7242-2244-393 Denmark Microchip Technology Nordic ApS Regus Business Centre Lautrup hoj 1-3 Ballerup DK-2750 Denmark Tel: 45 4420 9895 Fax: 45 4420 9910 France Microchip Technology SARL Parc d’Activite du Moulin de Massy 43 Rue du Saule Trapu Batiment A - ler Etage 91300 Massy, France Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79 Germany Microchip Technology GmbH Steinheilstrasse 10 D-85737 Ismaning, Germany Tel: 49-89-627-144 0 Fax: 49-89-627-144-44 Italy Microchip Technology SRL Centro Direzionale Colleoni Palazzo Taurus 1 V. Le Colleoni 1 20041 Agrate Brianza Milan, Italy Tel: 39-039-65791-1 Fax: 39-039-6899883 United Kingdom Microchip Ltd. 505 Eskdale Road Winnersh Triangle Wokingham Berkshire, England RG41 5TU Tel: 44 118 921 5869 Fax: 44-118 921-5820 08/01/02 DS21449C-page 28 2002 Microchip Technology Inc.