MICROCHIP TC647VUA

M
TC647
PWM Fan Speed Controller with 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 TC647
Supply Voltage
- Supports any Fan Voltage
• FanSense™ Technology Fault Detection Circuits
Protect Against Fan Failure and Aid System
Testing
• Shutdown Mode for "Green" Systems
• Supports Low Cost NTC/PTC Thermistors
• Space Saving 8-Pin MSOP Package
Applications
•
•
•
•
•
•
Power Supplies
Personal Computers
File Servers
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
VMIN
GND
8
VDD
7
VOUT
3
6
FAULT
4
5
SENSE
TC647
General Description
The TC647 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 VIN furnishes the
required control voltage of 1.25V to 2.65V (typical) for
0% to 100% PWM duty cycle. Minimum fan speed is
set by a simple resistor divider on the VMIN input. An
integrated Start-up Timer ensures reliable motor startup at turn-on, coming out of shutdown mode or
following a transient fault. A logic low applied to V MIN
(Pin 3) causes fan shutdown.
The TC647 also features Microchip Technology's proprietary FanSense™ technology for increasing system
reliability. In normal fan operation, a pulse train is
present at SENSE (Pin 5). A missing pulse detector
monitors this pin during fan operation. A stalled, open
or unconnected fan causes the TC647 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.
The TC647 is available in the 8-pin plastic DIP, SOIC
and MSOP packages and is available in the industrial
and extended commercial temperature ranges.
 2002 Microchip Technology Inc.
DS21447C-page 1
TC647
Functional Block Diagram
VIN
–
VDD
+
SHDN
–
+
Control
Logic
VOUT
CF
3 x TPWM
Timer
Clock
Generator
VMIN
Start-up
Timer
+
VSHDN
–
FAULT
Missing
Pulse
Detect.
TC647
+
–
GND
10kΩ
SENSE
70mV (typ.)
DS21447C-page 2
 2002 Microchip Technology Inc.
TC647
1.0
ELECTRICAL
CHARACTERISTICS
*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.
Absolute Maximum Ratings*
Supply Voltage ......................................................... 6V
Input Voltage, Any Pin.... (GND – 0.3V) to (VDD +0.3V)
Package Thermal Resistance:
PDIP (RθJA)............................................. 125°C/W
SOIC (RθJA) ............................................ 155°C/W
MSOP (R θJA) .......................................... 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
mA
Pins 6, 7 Open,
CF = 1 µF, VIN = VC(MAX)
IDD(SHDN)
Supply Current,
Shutdown Mode
—
25
—
µA
Pins 6, 7 Open,
CF = 1 µF, VMIN = 0.35V
IIN
VIN , VMIN Input Leakage
– 1.0
—
+1.0
µA
Note 1
VOUT Output
tR
VOUT Rise Time
—
—
50
µsec
IOH = 5 mA, Note 1
tF
VOUT Fall Time
—
—
50
µsec
IOL = 1 mA, Note 1
tSHDN
Pulse Width (On VMIN ) 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 VOUT Output
5.0
—
—
mA
VOH = 80% of VDD
VC(MAX)
Input Voltage at VIN or VMIN for
100% PWM Duty Cycle
2.5
2.65
2.8
V
VC(SPAN)
VC(MAX) - VC(MIN)
1.3
1.4
1.5
V
VSHDN
Voltage Applied to VMIN to
Ensure Shutdown Mode
—
—
VDD x 0.13
V
VREL
Voltage Applied to VMIN to
Release Shutdown Mode
VDD x 0.19
—
—
V
PWM Frequency
26
30
34
Hz
CF = 1.0 µF
SENSE Input Threshold
Voltage with Respect to GND
50
70
90
mV
Note 1
VOL
Output Low Voltage
—
—
0.3
V
tMP
Missing Pulse Detector Timer
—
32/F
—
Sec
tSTARTUP
Start-up Timer
—
32/F
—
Sec
tDIAG
Diagnostic Timer
—
3/F
—
Sec
VIN , VMIN Inputs
VDD = 5V
Pulse Width Modulator
FPWM
SENSE Input
VTH(SENSE)
FAULT Output
IOL = 2.5 mA
Note 1: Ensured by design, not tested.
 2002 Microchip Technology Inc.
DS21447C-page 3
TC647
2.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1:
Pin No.
PIN FUNCTION TABLE
Symbol
Description
1
VIN
Analog Input
2
CF
Analog Output
2.3
Analog Input (VMIN)
An external resistor divider connected to the V MIN input
sets the minimum fan speed by fixing the minimum
PWM duty cycle (1.25V to 2.65V = 0% to 100%, typical). The TC647 enters shutdown mode when VMIN ≤
VSHDN. During shutdown, the FAULT output is inactive
and supply current falls to 25 µA (typical). The TC647
exits shutdown mode when VMIN ≥ VREL. See
Section 5.0, “Typical Applications”, for more details.
3
VMIN
Analog Input
4
GND
Ground Terminal
2.4
5
SENSE
Analog Input
GND denotes the ground terminal.
6
FAULT
Digital (Open Collector) Output
7
VOUT
Digital Output
2.5
8
VDD
Power Supply Input
Pulses are detected at the SENSE pin as fan rotation
chops the current through a sense resistor. The
absence of pulses indicates a fault.
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.
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.
2.6
Ground (GND)
Analog Input (SENSE)
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. FAULT may be connected to VMIN if a hard shutdown is desired.
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”).
DS21447C-page 4
 2002 Microchip Technology Inc.
TC647
3.0
DETAILED DESCRIPTION
3.1
PWM
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 CF
input. A frequency of 30 Hz is recommended
(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 this data sheet. This output has an
asymmetric complimentary 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 mode. If
the PWM frequency is 30 Hz (CF = 1 µF), the resulting
start-up time will be approximately one second. If a
fault is detected, the Diagnostic Timer is triggered
once, followed by the Start-up Timer. If the fault
persists, the device is shut down (see Section 3.6,
“FAULT Output”).
3.4
Shutdown Control (Optional)
If VMIN (Pin 3) is pulled below VSHDN, the TC647 will go
into shutdown mode. This can be accomplished by
driving VMIN with an open-drain logic signal or using an
external transistor, as shown in Figure 3-1. All functions
are suspended until the voltage on V MIN becomes
higher than V REL (0.85V @ V DD = 5.0V). Pulling V MIN
below VSHDN will always result in complete device
shutdown and reset. The FAULT output is
unconditionally inactive in shutdown mode.
A small amount of hysteresis, typically one percent of
VDD (50 mV at VDD = 5.0V), is designed into the VSHDN/
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.
 2002 Microchip Technology Inc.
CAUTION: Shutdown mode is unconditional. That is,
the fan will not be activated regardless of the voltage
at VIN. The fan should not be shut down until all heat
producing activity in the system is at a negligible
level.
3.5
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 mode, and pulses are not appearing at the
SENSE input, a fault exists.
The short, rapid change in fan current (high dI/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.
3.6
FAULT Output
Pulses appearing at SENSE due to the PWM turning
on are blanked with the remaining pulses being filtered
by a missing pulse detector. If consecutive pulses are
not detected for 32 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, “StartUp 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.
Note:
At this point, action must be taken to restart
the fan by momentarily pulling VMIN below
VSHDN, or cycling system power. In either
case, the fan cannot remain disabled due
to a fault condition as severe system damage could result. If the fan cannot be
restarted, the system should be shut down.
The TC647 may be configured to continuously attempt
fan restarts, if so desired.
DS21447C-page 5
TC647
Continuous restart mode is enabled by connecting the
FAULT output to VMIN through a 0.1 µF capacitor, as
shown in Figure 3-1. When so connected, the TC647
automatically attempts to restart the fan whenever a
fault condition occurs. When the FAULT output is
driven low, the VMIN input is momentarily pulled below
VSHDN, initiating a reset and clearing the fault
condition. 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
microcontroller) to shut the TC647 down if multiple fault
pulses are detected at approximately one second
intervals.
+5V
10 kΩ
C1
+5V
0.01µF
+12V
1 kΩ
TC647
CB
1µF
From
Temp
Sensor
RESET
8
1
VIN
Fan
VDD
FAULT
6
1
0
Q1
Fault
Detected
+5V
TC647
R3
VOUT
RBASE
7
3 V
MIN
CB
From
System
Shutdown
Controller
R1
Q2
(Optional)
0.01 µF 2
R4
CF
1 µF
SENSE
5
CSENSE
CF
GND
4
RSENSE
Note: The parallel combination of R3 and R4 must be >10 kΩ.
FIGURE 3-1:
DS21447C-page 6
Fan Fault Output Circuit.
 2002 Microchip Technology Inc.
TC647
4.0
SYSTEM BEHAVIOR
The flowcharts describing the TC647’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
mode (VMIN > V REL)…
(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 TC647 is
latched in shutdown mode. This mode can only be
released by a reset (i.e., VMIN being brought below
VSHDN, then above VREL, 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 VMIN 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 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 TC647 in shutdown? If so…
a. V OUT duty cycle goes to zero.
b. FAULT is disabled.
c. Exit the loop and wait for VMIN > VREL to resume
operation (indistinguishable from Power-up).
(3) Drive VOUT to a duty cycle proportional to greater
of V IN and VMIN 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.
DS21447C-page 7
TC647
Normal
Operaton
Power-Up
Clear
Missing Pulse
Detector
Power-on
Reset
FAULT = 1
Yes
Shutdown
VOUT = 0
VMIN < VSHDN
Yes
Shutdown
VOUT = 0
VMIN < VSHDN?
No
No
VMIN > VREL?
No
VMIN > VREL
No
Yes
Yes
Fire Start-up
Timer
(1 SEC)
Fan Fault
Detected?
Power-up
Yes
Yes
No
Normal
Operation
Fire Start-up
Timer
YES
(1 SEC)
Fan Pulse
Detected?
VOUT
Proportional to Greater
of VIN or VMIN
No
Fan Fault
Yes
Fan Pulse
Detected?
Fan Fault
No
No
M.P.D.
Expired?
Yes
Fire Diagnostic
Timer
(100msec)
FAULT = 0,
VOUT = 0
No
No
VMIN < VSHDN?
Yes
No
Fan Pulse
Detected?
Cycling
Power?
Yes
Yes
Yes
VMIN > VREL?
Fire Start-up
Timer
(1 SEC)
No
Fan Pulse
Detected?
No
Fan Fault
Yes
Power-up
FIGURE 4-1:
DS21447C-page 8
TC647 Behavioral Algorithm Flowchart.
 2002 Microchip Technology Inc.
TC647
5.0
TYPICAL APPLICATIONS
The TC642 demonstration and prototyping board
(TC642DEMO) and the TC642 Evaluation Kit
(TC642EV) provide working examples of TC647 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 TC647 should consult the documentation for both TC642EV and (DS21403) and
TC642DEMO (DS21401). Figure 5-1 shows the base
schematic for the TC642DEMO.
Designing with the TC647 involves the following:
(1) The temp sensor network must be configured to
deliver 1.25V to 2.65V on VIN for 0% to 100% of
the temperature range to be regulated.
(2) The minimum fan speed (V MIN) must be set.
(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*
+12V
CB
1 µF
NTC
R1
8
1
VIN
Fan
VDD
CB
0.01 µF
R2
6
FAULT
Fan Fault
Shutdown
Q1
RBASE
TC647
VOUT
R3
3
CB
0.01 µF
Shutdown
R4
(Optional)
7
VMIN
5
SENSE
2
CSENSE
CF
CF
1 µF
GND
RSENSE
4
Note: *See cautions regarding latch-up considerations in Section 5.0, "Typical Applications".
FIGURE 5-1:
Typical Application Circuit.
 2002 Microchip Technology Inc.
DS21447C-page 9
TC647
5.1
Temperature Sensor Design
EQUATION
VDD x R2
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
R1 = 100 kΩ
VIN
R2 = 23.2 kΩ
FIGURE 5-2:
Circuit.
Temperature Sensing
Figure 5-2 illustrates a simple temperature dependent
voltage divider circuit. RT1 is a conventional 100 kΩ @
25°C NTC thermistor, while R1 and R 2 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 non-linear
device with a negative temperature coefficient (also
called an NTC thermistor). In Figure 5-2, R1 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
TC647. 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:
DS21447C-page 10
VDD x R2
RTEMP (T2) + R2
= V(T2)
Where T1 and T2 are the chosen temperatures and
RTEMP is the parallel combination of the thermistor
and R1.
IDIV
RT1
NTC
Thermistor
100 kΩ @ 25ºC
= V(T1)
RTEMP (T1) + R2
These two equations facilitate solving for the two
unknown variables, R1 and R2. More information about
Thermistors may be obtained from AN679, “Temperature Sensing Technologies”, and AN685, “Thermistors
in Single Supply Temperature Sensing Circuits”, which
can be downloaded from Microchip’s website at
www.microchip.com.
5.2
Minimum Fan Speed
A voltage divider on VMIN sets the minimum PWM duty
cycle and, thus, the minimum fan speed. As with the
VIN input, 1.25V to 2.65V corresponds to 0% to 100%
duty cycle. Assuming that fan speed is linearly related
to duty cycle, the minimum speed voltage is given by
the equation:
EQUATION
VMIN =
Minimum Speed
x (1.4V) + 1.25V
Full Speed
For example, if 2500 RPM equates to 100% fan speed,
and a minimum speed of 1000 RPM is desired, then
the VMIN voltage is:
EQUATION
VMIN =
1000
2500
x (1.4V) + 1.25V = 1.81V
The V MIN voltage may be set using a simple resistor
divider as shown in Figure 5-3. Per Section 1.0,
“Electrical Characteristics”, the leakage current at the
VMIN pin is no more than 1 µA. It would be very
conservative to design for a divider current, IDIV, of
100 µA. If VDD = 5.0V then;
EQUATION
IDIV = 1e–4A =
R1 + R2 =
5.0V
R1 + R2
5.0V
1e–4A
, therefore
= 50,000 Ω = 50 kΩ
 2002 Microchip Technology Inc.
TC647
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.
VDD
R1
IDIV
IIN
VMIN
R2
GND
VMIN Circuit.
FIGURE 5-3:
We can further specify R1 and R 2 by the condition that
the divider voltage is equal to our desired VMIN. This
yields the following equation:
EQUATION
VMIN =
VDD x R2
R1 + R2
Solving for the relationship between R1 and R 2 results
in the following equation:
EQUATION
R1 = R2 x
VDD - VMIN
VMIN
In this example, R1 = (1.762) R2. Substituting this relationship back into the previous equation 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 TC647 may fail
to capture a pulse within the 32-cycle missing pulse
detector window. When 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 will accelerate briefly when the
Diagnostic Timer fires. For this reason, it is
recommended that VMIN be set no lower than 1.8V.
5.4
FanSense™ Network
(RSENSE and CSENSE)
The FanSense network, comprised of RSENSE and
CSENSE, allows the TC647 to detect commutation of
the fan motor (FanSense™ technology). This network
can be thought of as a differentiator and threshold
detector. The function of RSENSE 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 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.
VDD
R2 = 18.1 kΩ
R1 = 31.9 kΩ
In this case, the standard values of 31.6 kΩ and
18.2 kΩ are very close to the calculated values and
would be more than adequate.
5.3
FAN
Operations at Low Duty Cycle
One boundary condition which may impact the selection of the minimum fan speed is the irregular activation
of the Diagnostic Timer due to the TC647 “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
RBASE
VOUT
SENSE
CSENSE
(0.1 µF Typ.)
RSENSE
GND
FIGURE 5-4:
 2002 Microchip Technology Inc.
Q1
SENSE Network.
DS21447C-page 11
TC647
5.5
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
142mV
Ch1
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
not 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.
R SENSE VS. FAN CURRENT
TABLE 5-1:
Nominal Fan Current (mA)
RSENSE (Ω)
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
DS21447C-page 12
Output Drive Transistor Selection
The TC647 is designed to drive an external transistor
or MOSFET for modulating power to the fan. This is
shown as Q1 in Figures 3-1, 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 5-7. 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 5-7: (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 TC647’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”.
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
Q 1 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
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
R DS(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.
A base-current limiting resistor is required with bipolar
transistors. This is shown in Figure 5-6.
 2002 Microchip Technology Inc.
TC647
The correct value for this resistor can be determined as
follows:
VDD
Fan
Q1
–
+ VR
BASE
+ VBE
= VRSENSE + VBE(SAT) + VRBASE
VRSENSE
= IFAN x RSENSE
VRBASE
= RBASE x IBASE
IBASE
= IFAN / hFE
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
VOH
–
EQUATION
(SAT)
+
VRSENSE
RSENSE
RBASE =
–
TABLE 5-2:
Device
MMBT2222A
MPS2222A
MPS6602
IBASE
Some applications require the fan to be powered from the
negative 12V supply to keep motor noise out of the
positive voltage power supplies. As shown in Figure 5-8,
zener diode D1 offsets 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
the case of fan operation from +12V.
GND
FIGURE 5-6:
R BASE.
VOH - VBE(SAT) - V RSENSE
Circuit For Determining
TRANSISTORS AND MOSFETS FOR Q1 (VDD = 5V)
Package
Max. VBE(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.
DS21447C-page 13
TC647
VDD
VDD
VDD
Fan
Fan
Fan
RBASE
RBASE
VOUT
VOUT
Q1
Q1
Q1
VOUT
Q2
RSENSE
RSENSE
RSENSE
GND
b) Darlington Transistor Pair
a) Single Bipolar Transistor
FIGURE 5-7:
C) N-Channel MOSFET
Output Drive Transistor Circuit Topologies.
ing points can result in enough parasitic capacitance
and/or inductance in the power supply connections to
delay one power supply “routing” versus another.
+5V
VDD
R2 *
2.2 kΩ
VOUT
TC647
5.7
Fan
D1
12.0V
Zener
Q1 *
GND
R4 *
10 kΩ
R3 *
2.2 Ω
-12V
*Note: Value depends on the specific application and is shown for example only.
FIGURE 5-8:
-12V Supply.
5.6
GND
GND
Powering the Fan from a
Latch-Up Considerations
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, VMIN divider or shutdown circuit) is
powered by a supply different from that of the TC647.
Care should be taken to ensure that the TC647’s VDD
supply powers up first. If possible, the networks
attached to VIN and V MIN 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 connect-
DS21447C-page 14
Power Supply Routing and
Bypassing
Noise present on the VIN and VMIN 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 particularly true of VIN, which is usually driven from a
high impedance source (such as a thermistor). In addition, the VDD input should be bypassed with a 1 µF
capacitor. Ground should be kept as short as possible.
To keep fan noise off the TC647 ground pin, individual
ground returns for the TC647 and the low side of the
fan current sense resistor should be used.
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 minimum fan speed VMIN = 1.8V.
Limit the divider current to 100 µA from which
R5 = 33 kΩ and R 6 = 18 kΩ
Step 3. Design the output circuit.
Maximum fan motor current = 250 mA.
Q 1 beta is chosen at 50 from which
R7 = 800Ω.
 2002 Microchip Technology Inc.
TC647
+5V
+5V
R1
20.5 kΩ
R2
3.83 kΩ
NTC
CB +
10 kΩ 1 µF
@ 25°C
1
VIN
CB
0.01 µF
+12V
8
VDD
Fan
4
GND
6
FAULT
System
Fault
+5V
TC647
R5
33 kΩ
Fan Shutdown
Q2
R8
10 kΩ
R6
18 kΩ
3
CB
0.01 µF
2
(Optional)
FIGURE 5-9:
5.8
Q1
R7
800 Ω
VOUT
7
VMIN
SENSE
CF
C1
1 µF
5
CSENSE
0.1 µF
RSENSE
2.2 Ω
Design Example.
TC647 as a Microcontroller
Peripheral
In a system containing a microcontroller or other host
intelligence, the TC647 can be effectively managed as
a CPU peripheral. Routine fan control functions can be
performed by the TC647 without controller 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 complimentary port bits I/O1
through I/O3. Resistors R1 through R6 (5% tolerance)
form a crude 3-bit DAC that translates the 3-bit code
from the controller or 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 V MIN set to 1.8V, the TC647 has a minimum
operating speed of approximately 40% of full rated
speed 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/O can be used to reset the
TC647 following detection of a fault condition. The
FAULT output can be connected to the processor's
interrupt input, or to an I/O pin, for polled operation (see
Figure 5-10).
 2002 Microchip Technology Inc.
DS21447C-page 15
TC647
+12V
+5V
Open-drain
(RESET) (Optional)
Outputs I/O0
I/O1
Analog or Digital
Temperature
Data from one or
more Sensors
CMOS
Outputs
1
R2
240 kΩ
I/O2
CB
.01 µF
R3
360 kΩ
I/O3
CMOS
Microcontroller
+5V
R1
(MSB) 110 kΩ
(LSB)
R5
1.5 kΩ
+5V
R6
1 kΩ
R7
33 kΩ
+5V
R8
18 kΩ
VDD
2
CF
+
R4
18 kΩ
VIN
1 µF
3
CB
.01 µF
4
VOUT
CB +
1 µF
R9
800Ω
7
TC647
VMIN
FAULT
GND
SENSE
Fan
8
6
5
2N2222A
+5V
R10
10 kΩ
0.1 µF
R11
2.2Ω
GND
FIGURE 5-10:
DS21447C-page 16
INT
TC647 as a Microcontroller Peripheral.
 2002 Microchip Technology Inc.
TC647
6.0
PACKAGING INFORMATION
6.1
Package Marking Information
8-Lead PDIP (300 mil)
XXXXXXXX
NNN
YYWW
TC647VPA
025
0215
8-Lead SOIC (150 mil)
XXXXXXXX
YYWW
NNN
YWWNNN
Note:
*
TC647VOA
0215
025
TC647E
215025
XXXXXX
XX...X
YY
WW
NNN
Example:
Example:
8-Lead MSOP
Legend:
Example:
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.
DS21447C-page 17
TC647
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
DS21447C-page 18
 2002 Microchip Technology Inc.
TC647
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.
DS21447C-page 19
TC647
6.2
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
DS21447C-page 20
 2002 Microchip Technology Inc.
TC647
6.3
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
DS21447C-page 21
TC647
NOTES:
DS21447C-page 22
 2002 Microchip Technology Inc.
TC647
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.
DS21447C-page23
TC647
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: TC647
Y
N
Literature Number: DS21447C
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?
DS21447C-page24
 2002 Microchip Technology Inc.
TC647
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:
TC647:
PWM Fan Speed Controller w/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
= 0°C to +85°C
= -40°C to +85°C
Examples:
a)
TC647VOA: PWM Fan Speed Controller w/
Fault Detection, SOIC package.
b)
TC647VUA: PWM Fan Speed Controller w/
Fault Detection, MSOP package.
c)
TC647VPA: PWM Fan Speed Controller w/
Fault Detection, PDIP package.
d)
TC647EOATR: PWM Fan Speed Controller
w/Fault Detection, SOIC package, Tape and
Reel.
* 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.
DS21447C-page25
TC647
NOTES:
DS21447C-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.
DS21447C - 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
DS21447C-page 28
 2002 Microchip Technology Inc.