TC647BEUA713 [MICROCHIP]
PWM Fan Speed Controllers With Minimum Fan Speed, Fan Restart and FanSense⑩ Technology for Fault Detection; PWM风扇速度控制器，带有风扇的最低转速，风扇重启和FanSense⑩技术故障检测
| 型号： | TC647BEUA713 |
| 厂家： | 
MICROCHIP |
| 描述： | PWM Fan Speed Controllers With Minimum Fan Speed, Fan Restart and FanSense⑩ Technology for Fault Detection |
| 文件： | 总34页 (文件大小：663K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
TC642B/TC647B
M
PWM Fan Speed Controllers With Minimum Fan Speed,
Fan Restart and FanSense™ Technology for Fault Detection
Features
Description
• Temperature-Proportional Fan Speed for Acoustic
The TC642B/TC647B devices are new versions of the
existing TC642/TC647 fan speed controllers. These
devices are switch mode, fan speed controllers that
incorporate a new fan auto-restart function. Tempera-
ture-proportional speed control is accomplished using
pulse width modulation. A thermistor (or other voltage
Noise Reduction and Longer Fan Life
• Efficient PWM Fan Drive
• 3.0V to 5.5V Supply Range:
- Fan Voltage Independent of TC642B/TC647B
Supply Voltage
output temperature sensor) connected to the V input
IN
- Supports any Fan Voltage
supplies the required control voltage of 1.20V to 2.60V
(typical) for 0% to 100% PWM duty cycle. Minimum fan
• FanSense™ Fault Detection Circuit Protects
Against Fan Failure and Aids System Testing
speed is set by a simple resistor divider on the V
MIN
input. An integrated Start-Up Timer ensures reliable
motor start-up at turn-on, coming out of shutdown
mode or following a transient fault. A logic-low applied
• Shutdown Mode for "Green" Systems
• Supports Low Cost NTC/PTC Thermistors
• Over-Temperature Indication (TC642B only)
• Fan Auto-Restart
to V
(pin 3) causes fan shutdown.
MIN
The TC642B and TC647B also feature Microchip
• Space-Saving 8-Pin MSOP Package
™
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 TC642B/
Applications
• Personal Computers & Servers
• LCD Projectors
• Datacom & Telecom Equipment
• Fan Trays
TC647B device to turn the V
output on full (100%
OUT
duty cycle). If the fault persists (a fan current pulse is
not detected within a 32/f period), the FAULT output
• File Servers
• General Purpose Fan Speed Control
goes low. Even with the FAULT output low, the V
OUT
output is on full during the fan fault condition in order to
attempt to restart the fan. FAULT is also asserted if the
PWM reaches 100% duty cycle (TC642B only), indicat-
ing that maximum cooling capability has been reached
and a possible overheating condition exists.
Package Types
MSOP, PDIP, SOIC
The TC642B and TC647B devices are available in 8-pin
plastic MSOP, SOIC and PDIP packages. The specified
temperature range of these devices is -40 to +85ºC.
V
1
2
3
4
8
7
6
5
V
V
IN
DD
C
F
OUT
TC642B
TC647B
V
FAULT
MIN
GND
SENSE
2003 Microchip Technology Inc.
DS21756B-page 1
TC642B/TC647B
Functional Block Diagram
TC642B/TC647B
V
OTF
V
V
V
IN
DD
Note
Note: The V
comparator
OTF
is for the TC642B device only.
Control
Logic
C
3xT
F
PWM
Timer
OUT
Clock
Generator
Start-up
Timer
V
MIN
FAULT
Missing
Pulse
V
SHDN
Detect
SENSE
10 kΩ
GND
70 mV
(typ)
DS21756B-page 2
2003 Microchip Technology Inc.
TC642B/TC647B
1.0
ELECTRICAL
PIN FUNCTION TABLE
CHARACTERISTICS
Name
Function
Analog Input
Absolute Maximum Ratings †
V
IN
C
Analog Output
Analog Input
Supply Voltage (VDD) .......................................................6.0V
Input Voltage, Any Pin................(GND - 0.3V) to (VDD +0.3V)
Operating Temperature Range ....................- 40°C to +125°C
Maximum Junction Temperature, TJ ...........................+150°C
ESD Protection on all pins ........................................... > 3 kV
† Notice: Stresses above those listed under “Maximum
Ratings” may cause permanent damage to the device. This is
a stress rating only and functional operation of the device at
those or any other conditions above those indicated in the
operational listings of this specification is not implied. Expo-
sure to maximum rating conditions for extended periods may
affect device reliability.
F
V
MIN
GND
Ground
SENSE
FAULT
Analog Input
Digital (Open-Drain) Output
Digital Output
V
OUT
V
Power Supply Input
DD
ELECTRICAL SPECIFICATIONS
Electrical Specifications: Unless otherwise specified, all limits are specified for -40°C < TA < +85°C, VDD = 3.0V to 5.5V.
Parameters
Supply Voltage
Sym
Min
Typ
Max
Units
Conditions
VDD
IDD
3.0
—
—
5.5
V
Supply Current, Operating
200
400
µA
Pins 6, 7 Open,
CF = 1 µF, VIN = VC(MAX)
Supply Current, Shutdown Mode
IDD(SHDN)
—
30
—
µA
Pins 6, 7 Open,
CF = 1 µF, VMIN = 0.35V
VOUT Output
Sink Current at VOUT Output
Source Current at VOUT Output
VIN, VMIN Inputs
IOL
IOH
1.0
5.0
—
—
—
—
mA VOL = 10% of VDD
mA VOH = 80% of VDD
Input Voltage at VIN or VMIN for 100%
PWM Duty Cycle
VC(MAX)
VOTF
2.45
2.60
2.75
V
Over-Temperature Indication
Threshold
VC(MAX)
20 mV
+
V
For TC642B Only
For TC642B Only
Over-Temperature Indication
Threshold Hysteresis
VOTF-HYS
80
mV
VC(MAX) - VC(MIN)
VC(SPAN)
VMIN
1.3
1.4
1.5
V
V
Minimum Speed Threshold
VC(MAX)
VC(SPAN)
-
VC(MAX)
Voltage Applied to VMIN to Ensure
Shutdown Mode
VSHDN
VREL
—
—
—
VDD x 0.13
—
V
V
Voltage Applied to VMIN to Release
Shutdown Mode
VDD x 0.19
VDD = 5V
Hysteresis on VSHDN, VREL
VIN, VMIN Input Leakage
Pulse-Width Modulator
PWM Frequency
VHYST
IIN
—
0.03 x VDD
—
—
V
- 1.0
+1.0
µA
Note 1
fPWM
26
30
34
Hz
CF = 1.0 µF
Note 1: Ensured by design, tested during characterization.
2: For VDD < 3.7V, tSTARTUP and tMP timers are typically 13/f.
2003 Microchip Technology Inc.
DS21756B-page 3
TC642B/TC647B
ELECTRICAL SPECIFICATIONS (CONTINUED)
Electrical Specifications: Unless otherwise specified, all limits are specified for -40°C < TA < +85°C, VDD = 3.0V to 5.5V.
Parameters
SENSE Input
Sym
Min
Typ
Max
Units
Conditions
SENSE Input Threshold Voltage with
Respect to GND
VTH(SENSE)
tBLANK
50
—
70
90
—
mV
Blanking time to ignore pulse due to
3.0
µsec
VOUT turn-on
FAULT Output
Output Low Voltage
VOL
tMP
—
—
—
—
—
32/f
32/f
3/f
0.3
—
V
IOL = 2.5 mA
Missing Pulse Detector Timer
Start-Up Timer
sec Note 2
sec Note 2
sec
tSTARTUP
tDIAG
—
Diagnostic Timer
—
Note 1: Ensured by design, tested during characterization.
2: For VDD < 3.7V, tSTARTUP and tMP timers are typically 13/f.
TEMPERATURE SPECIFICATIONS
Electrical Characteristics: Unless otherwise noted, all parameters apply at VDD = 3.0V to 5.5V
Parameters
Symbol
Min
Typ
Max
Units
Conditions
Temperature Ranges:
Specified Temperature Range
Operating Temperature Range
Storage Temperature Range
TA
TA
TA
-40
-40
-65
—
—
—
+85
+125
+150
°C
°C
°C
Thermal Package Resistances:
Thermal Package Resistance, 8-Pin MSOP
Thermal Package Resistance, 8-Pin SOIC
Thermal Package Resistance, 8-Pin PDIP
—
—
—
—
—
—
θJA
θJA
θJA
200
155
125
°C/W
°C/W
°C/W
DS21756B-page 4
2003 Microchip Technology Inc.
TC642B/TC647B
TIMING SPECIFICATIONS
tSTARTUP
V
OUT
FAULT
SENSE
FIGURE 1-1:
TC642B/TC647B Start-Up Timing.
33.3 msec (C = 1 µF)
F
t
DIAG
t
t
MP
MP
V
OUT
FAULT
SENSE
FIGURE 1-2:
Fan Fault Occurrence.
t
MP
V
OUT
FAULT
Minimum 16 pulses
SENSE
FIGURE 1-3:
Recovery From Fan Fault.
2003 Microchip Technology Inc.
DS21756B-page 5
TC642B/TC647B
C
1 µF
C
0.1 µF
2
1
+
-
V
DD
8
R
1
V
DD
1
K
R
3
V
6
IN
7
C
3
V
OUT
+
-
0.1 µF
V
C
0.1 µF
IN
8
Current
limited
voltage
source
+
-
R
V
3
2
DD
TC642B
TC647B
V
MIN
R
5
C
4
K
4
+
0.1 µF
V
6
5
MIN
-
FAULT
Current
limited
voltage
source
+
-
2
C
R
F
4
SENSE
GND
4
K
K
2
1
R
3
V
SENSE
(pulse voltage source)
C
C
5
0.1 µF
C
7
6
.01 µF
1 µF
Note: C and C are adjusted to get the necessary 1 µF value.
5
7
FIGURE 1-4:
TC642B/TC647B Electrical Characteristics Test Circuit.
DS21756B-page 6
2003 Microchip Technology Inc.
TC642B/TC647B
2.0
TYPICAL PERFORMANCE CURVES
Note: The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.
Note: Unless otherwise indicated, V = 5V, T = +25°C.
DD
A
30.50
30.00
29.50
29.00
28.50
165
160
155
150
145
140
135
130
125
Pins 6 & 7 Open
CF = 1 µF
CF = 1.0PF
VDD = 5.5V
VDD = 3.0V
VDD = 5.5V
VDD = 3.0V
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (ºC)
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (ºC)
FIGURE 2-1:
I
vs. Temperature.
FIGURE 2-4:
PWM Frequency vs.
DD
Temperature.
16
14
12
10
170
Pins 6 & 7 Open
F = 1 µF
165
160
155
150
145
140
135
130
125
C
VDD = 5.0V
TA = +125ºC
TA = +90ºC
VDD = 5.5V
VDD = 4.0V
8
6
4
2
0
VDD = 3.0V
TA = -5ºC
TA = -40ºC
0
50 100 150 200 250 300 350 400 450 500 550 600
VOL (mV)
3
3.5
4
4.5
5
5.5
VDD (V)
FIGURE 2-2:
OL
PWM Sink Current (I ) vs.
OL
FIGURE 2-5:
I
vs. V
.
DD
DD
V
.
16
14
12
10
8
30
27
24
21
18
VDD = 5.5V
VDD = 5.0V
VDD = 4.0V
VDD = 5.5V
VDD = 3.0V
VDD = 3.0V
6
4
Pins 6 & 7 Open
MIN = 0V
2
V
0
15
0
100
200
300
400
500
600
700
800
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (ºC)
VDD - VOH (mV)
FIGURE 2-3:
vs. V -V
PWM Source Current (I
)
FIGURE 2-6:
I
Shutdown vs.
OH
DD
.
Temperature.
DD OH
2003 Microchip Technology Inc.
DS21756B-page 7
TC642B/TC647B
Note: Unless otherwise indicated, V = 5V, T = +25°C.
DD
A
70
60
50
40
30
20
10
74.0
73.5
73.0
72.5
72.0
71.5
71.0
70.5
70.0
69.5
IOL = 2.5 mA
VDD = 4.0V
VDD = 3.0V
VDD = 3.0V
VDD = 4.0V
VDD = 5.5V
VDD = 5.0V
VDD = 5.0V
VDD = 5.5V
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (ºC)
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (ºC)
FIGURE 2-7:
FAULT V vs.
FIGURE 2-10:
Sense Threshold
OL
Temperature.
(V
) vs. Temperature.
TH(SENSE)
2.610
2.600
2.590
2.580
22
20
18
16
14
12
10
8
VDD = 5.5V
VDD = 5.0V
VDD = 5.0V
VDD = 5.5V
VDD = 4.0V
VDD = 3.0V
VDD = 3.0V
6
4
2
0
CF = 1 µF
-40 -25 -10
2.570
0
50
100
150
200
250
300
350
400
5
20 35 50 65 80 95 110 125
Temperature (ºC)
VOL (mV)
FIGURE 2-8:
V
vs. Temperature.
FIGURE 2-11:
FAULT I vs. V
.
OL
C(MAX)
OL
1.220
45.00
40.00
35.00
30.00
25.00
20.00
15.00
CF = 1 µF
VOH = 0.8VDD
VDD = 5.0V
VDD = 5.5V
VDD = 4.0V
1.210
1.200
1.190
1.180
VDD = 5.0V
VDD = 3.0V
VDD = 3.0V
10.00
5.00
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (ºC)
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (ºC)
FIGURE 2-9:
V
vs. Temperature.
FIGURE 2-12:
PWM Source Current (I
)
C(MIN)
OH
vs. Temperature.
DS21756B-page 8
2003 Microchip Technology Inc.
TC642B/TC647B
Note: Unless otherwise indicated, V = 5V, T = +25°C.
DD
A
30
25
20
15
10
5
2.630
2.625
2.620
2.615
2.610
2.605
2.600
2.595
VOL = 0.1VDD
VDD = 5.0V
VDD = 5.5V
VDD = 5.0V
VDD = 5.5V
VDD = 4.0V
VDD = 3.0V
VDD = 3.0V
0
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (ºC)
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (ºC)
FIGURE 2-13:
PWM Sink Current (I ) vs.
FIGURE 2-16:
V
Threshold vs.
OL
OTF
Temperature.
Temperature.
0.80
0.75
0.70
100
95
90
85
80
75
VDD = 5.5V
VDD = 5.0V
0.65
0.60
0.55
0.50
0.45
0.40
0.35
0.30
VDD = 5.5V
VDD = 4.0V
VDD = 3.0V
VDD = 3.0V
70
-40 -25 -10
5
20 35 50 65 80 95 110 125
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (ºC)
Temperature (ºC)
FIGURE 2-14:
V
Threshold vs.
FIGURE 2-17:
Over-Temperature
SHDN
Temperature.
Hysteresis (V
) vs. Temperature.
OTF-HYS
1.00
0.95
0.90
0.85
0.80
0.75
0.70
0.65
0.60
0.55
0.50
0.45
0.40
VDD = 5.5V
VDD = 5.0V
VDD = 4.0V
VDD = 3.0V
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (ºC)
FIGURE 2-15:
V
Threshold vs.
REL
Temperature.
2003 Microchip Technology Inc.
DS21756B-page 9
TC642B/TC647B
3.5
Digital (Open-Drain) Output
(FAULT)
3.0
PIN FUNCTIONS
The description of the pins are given in Table 3-1.
The FAULT line goes low to indicate a fault condition.
When FAULT goes low due to a fan fault, the output will
remain low until the fan fault condition has been
removed (16 pulses have been detected at the SENSE
pin in a 32/f period). For the TC642B device, the FAULT
TABLE 3-1:
PIN FUNCTION TABLE
Pin
Name Function
1
2
3
4
5
6
7
8
V
C
V
Analog Input
Analog Output
IN
output will also be asserted when the V voltage
IN
F
reaches the V
treshold of 2.62V (typical). This gives
OTF
Analog Input
Ground
MIN
GND
an over-temperature/100% fan speed indication.
3.6
Digital Output (V
)
SENSE Analog Input
FAULT Digital (Open-Drain) Output
V
OUT
V
is an active-high complimentary output and
OUT
Digital Output
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. During a
OUT
V
Power Supply Input
DD
fan fault condition, the V
output is continuously on.
OUT
3.1
Analog Input (V )
IN
3.7
Power Supply Input (V
)
DD
The thermistor network (or other temperature sensor)
connects to V . A voltage range of 1.20V to 2.60V (typ-
The V pin with respect to GND provides power to the
IN
DD
ical) on this pin drives an active duty cycle of 0% to
device. This bias supply voltage may be independent of
the fan power supply.
100% on the V
pin.
OUT
3.2
Analog Output (C )
F
C is the positive terminal for the PWM ramp generator
F
timing capacitor. The recommended value for the C
capacitor is 1.0 µF for 30 Hz PWM operation.
F
3.3
Analog Input (V
)
MIN
An external resistor divider connected to V
sets the
MIN
minimum fan speed by fixing the minimum PWM duty
cycle (1.20V to 2.60V = 0% to 100%, typical). The
TC642B and TC647B devices enter shutdown mode
when 0 ≤ V
≤ V
. During shutdown, the FAULT
SHDN
MIN
output is inactive and supply current falls to 30 µA
(typical).
3.4
Analog Input (SENSE)
Pulses are detected at SENSE as fan rotation chops
the current through a sense resistor. The absence of
pulses indicates a fan fault condition.
DS21756B-page 10
2003 Microchip Technology Inc.
TC642B/TC647B
special heatsinking to remove the power being
dissipated in the package.
The other advantage of the PWM approach is that the
voltage being applied to the fan is always near 12V.
This eliminates any concern about not supplying a high
enough voltage to run the internal fan components,
which is very relevant in linear fan speed control.
4.0
DEVICE OPERATION
The TC642B/TC647B devices are a family of tempera-
ture proportional, PWM mode, fan speed controllers.
Features of the family include minimum fan speed, fan
auto-shutdown mode, fan auto-restart, remote shut-
down, over-temperature indication and fan fault
detection.
The TC642B/TC647B family is slightly different from
the original TC64X family, which includes the TC642,
TC646, TC647, TC648 and TC649 devices. Changes
have been made to adjust the operation of the device
during a fan fault condition.
4.2
PWM Fan Speed Control
The TC642B and TC647B devices implement PWM fan
speed control by varying the duty cycle of a fixed fre-
quency pulse train. The duty cycle of a waveform is the
on time divided by the total period of the pulse. For
example, a 100 Hz waveform (10 ms) with an on time
of 5.0 ms has a duty cycle of 50% (5.0 ms / 10.0 ms).
This example is illustrated in Figure 4-1.
The key change to the TC64XB family of devices
(TC642B, TC647B, TC646B, TC648B, TC649B) is that
the FAULT and V
outputs no longer “latch” to a
OUT
state during a fan fault condition. The TC64XB family
will continue to monitor the operation of the fan so that
when the fan returns to normal operation, the fan speed
controller will also return to normal operation (PWM
mode). The operation and features of these devices
are discussed in the following sections.
t
4.1
Fan Speed Control Methods
t
t
on
off
The speed of a DC brushless fan is proportional to the
voltage across it. This relationship will vary from fan to
fan and should be characterized on an individual basis.
The speed versus applied voltage relationship can then
be used to set up the fan speed control algorithm.
D = Duty Cycle
D = t / t
t = Period
t = 1/f
on
f = Frequency
There are two main methods for fan speed control. The
first is pulse width modulation (PWM) and the second
is linear. Using either method, the total system power
requirement to run the fan is equal. The difference
between the two methods is where the power is
consumed.
The following example compares the two methods for
a 12V, 120 mA fan running at 50% speed. With 6V
applied across the fan, the fan draws an average
current of 68 mA.
FIGURE 4-1:
Waveform.
Duty Cycle of a PWM
The TC642B and TC647B generate a pulse train with a
typical frequency of 30 Hz (C = 1 µF). The duty cycle
F
can be varied from 0% to 100%. The pulse train gener-
ated by the TC642B/TC647B device drives the gate of
an external N-channel MOSFET or the base of an NPN
transistor (shown in Figure 4-2). See Section 5.5, “Out-
put Drive Device Selection”, for more information.
Using a linear control method, there is 6V across the
fan and 6V across the drive element. With 6V and
68 mA, the drive element is dissipating 410 mW of
power.
Using the PWM approach, the fan voltage is modulated
at a 50% duty cycle with most of the 12V being dropped
across the fan. With 50% duty cycle, the fan draws an
RMS current of 110 mA and an average current of
12V
FAN
V
DD
72 mA. Using a MOSFET with a 1 ΩR
(a fairly
DS(on)
D
S
typical value for this low current), the power dissipation
Q
2
DRIVE
V
TC642B
TC647B
in the drive element would be: 12 mW (Irms * R
).
OUT
G
DS(on)
Using a standard 2N2222A NPN transistor (assuming
a Vce-sat of 0.8V), the power dissipation would be
58 mW (Iavg* Vce-sat).
GND
FIGURE 4-2:
The PWM approach to fan speed control results in
much less power dissipation in the drive element,
allowing smaller devices to be used while not requiring
PWM Fan Drive.
2003 Microchip Technology Inc.
DS21756B-page 11
TC642B/TC647B
By modulating the voltage applied to the gate of the
4.4
PWM Frequency & Duty Cycle Control
(C & V Pins)
MOSFET (Q
), the voltage that is applied to the
DRIVE
F
IN
fan is also modulated. When the V
pulse is high, the
OUT
The frequency of the PWM pulse train is controlled by
the C pin. By attaching a capacitor to the C pin, the
gate of the MOSFET is turned on, pulling the voltage at
the drain of Q
to zero volts. This places the full
F
F
DRIVE
frequency of the PWM pulse train can be set to the
desired value. The typical PWM frequency for a 1.0 µF
capacitor is 30 Hz. The frequency can be adjusted by
12V across the fan for the t period of the pulse. When
on
the duty cycle of the drive pulse is 100% (full on,
t
= t), the fan will run at full speed. As the duty cycle
on
raising or lowering the value of the capacitor. The C
is decreased (pulse on time “t ” is lowered), the fan
F
on
pin functions as a ramp generator. The voltage at this
pin will ramp from 1.20V to 2.60V (typically) as a saw-
tooth waveform. An example of this is shown in
Figure 4-3.
will slow down proportionally. With the TC642B and
TC647B devices, the duty cycle is controlled by either
the V or V
input, with the higher voltage setting the
IN
MIN
duty cycle. This is described in more detail in Section
5.5, “Output Drive Device Selection”.
2.8
CF = 1 µF
VCMAX
4.3
Fan Start-up
2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
Often overlooked in fan speed control is the actual start-
up control period. When starting a fan from a non-oper-
ating condition (fan speed is zero revolutions per minute
(RPM)), the desired PWM duty cycle or average fan
voltage can not be applied immediately. Since the fan is
at a rest position, the fan’s inertia must be overcome to
get it started. The best way to accomplish this is to apply
the full rated voltage to the fan for a minimum of one
second. This will ensure that in all operating environ-
ments, the fan will start and operate properly. An exam-
ple of the start-up timing is shown in Figure 1-1.
VCMIN
40
0
20
60
80
100
Time (msec)
FIGURE 4-3:
The duty cycle of the PWM output is controlled by the
voltage at the V input pin (or the V voltage, which-
C Pin Voltage.
F
A key feature of the TC642B/TC647B device is the
start-up timer. When power is first applied to the device,
(when the device is brought out of the shutdown mode
IN
MIN
ever is greater). The duty cycle of the PWM output is
of operation) the V
output will go to a high state for
OUT
produced by comparing the voltage at the V pin to the
IN
32 PWM cycles (one second for C = 1 µF). This will
F
voltage ramp at the C pin. When the voltage at the V
F
IN
drive the fan to full speed for this time-frame.
pin is 1.20V, the duty cycle will be 0%. When the volt-
During the start-up period, the SENSE pin is being
monitored for fan pulses. If pulses are detected during
this period, the fan speed controller will then move to
PWM operation (see Section 4.5, “Minimum Fan
Speed”, for more details on operation when coming out
of start-up). If pulses are not detected during the start-
up period, the start-up timer is activated again. If pulses
are not detected at the SENSE pin during this addi-
tional start-up period, the FAULT output will go low to
indicate that a fan fault condition has occurred. See
Section 4.7, “FAULT Output”, for more details.
age at the V pin is 2.60V, the PWM duty cycle will be
IN
100% (these are both typical values). The V to PWM
IN
duty cycle relationship is shown in Figure 4-4.
The lower value of 1.20V is referred to as V
and
CMIN
the 2.60V threshold is referred to as V
. A calcula-
CMAX
tion for duty cycle is shown in the equation below. The
voltage range between V and V is character-
CMIN
CMAX
ized as V
and has a typical value of 1.4V with
CSPAN
minimum and maximum values of 1.3V and 1.5V,
respectively.
EQUATION
PWM DUTY CYCLE
(V - V ) * 100
IN
CMIN
Duty Cycle (%) =
V
- V
CMIN
CMAX
DS21756B-page 12
2003 Microchip Technology Inc.
TC642B/TC647B
If the voltage at the V pin falls below 1.76V, the duty
IN
100
90
80
70
60
50
40
30
20
10
0
cycle of the V
output will not decrease below the
OUT
40% value that is now set by the voltage at the V
MIN
pin. In this manner, the fan will continue to operate at
40% speed even when the temperature (voltage at V )
continues to decrease.
IN
For the TC642B and TC647B devices, the V
pin is
MIN
also used as the shutdown pin. The V
and V
REL
SHDN
threshold voltages are characterized in the “Electrical
Characteristics” table of Section 1.0. If the V
pin
MIN
voltage is pulled below the V
threshold, the device
SHDN
1
1.2
1.4
1.6
1.8
VIN (V)
2
2.2
2.4
2.6
2.8
will shut down (V
output goes to a low state, the
OUT
FAULT pin is inactive). If the voltage on the V
pin
MIN
then rises above the release threshold (V
), the
REL
FIGURE 4-4:
V
voltage vs. PWM duty
IN
device will go through a Power-Up sequence. The
Power-Up sequence is shown later in Figure 4-9.
cycle(Typical).
The PWM duty cycle is also controlled by the V
See Section 4.5, “Minimum Speed (V
more details on this function.
pin
MIN
4.6
V
OUT
Output (PWM Output)
Pin)”, for
OUT
output is a digital output designed for driving
MIN
The V
the base of a transistor or the gate of a MOSFET. The
4.5
Minimum Speed (V
Pin)
MIN
V
output is designed to be able to quickly raise the
OUT
base current or the gate voltage of the external drive
device to its final value.
For the TC642B and TC647B devices, pin 3 is the V
pin. This pin is used for setting the minimum fan speed
threshold.
MIN
When the device is in shutdown mode, the V
output
OUT
is actively held low. The output can be varied from 0%
The minimum fan speed function provides a way to set
duty cycle (full off) to 100% duty cycle (full on). As pre-
a threshold for a minimum duty cycle on the V
out-
OUT
viously discussed, the duty cycle of the V
output is
OUT
put. This in turn produces a minimum fan speed for the
controlled via the V input voltage along with the V
IN
MIN
user. The voltage range for the V pin is the same as
MIN
voltage.
that for the V pin (1.20V to 2.60V). The voltage at the
IN
V
V
pin is set in this range so that as the voltage at the
A base current-limiting resistor is required when using
a transistor as the external drive device in order to limit
MIN
pin decreases below the V
voltage, the output
MIN
IN
duty cycle will be controlled by the V
following equation can be used to determine the neces-
sary voltage at V for a desired minimum duty cycle
voltage. The
the amount of drive current that is drawn from the V
output.
MIN
OUT
MIN
The V
output can be directly connected to the gate
OUT
on V
.
OUT
of an external MOSFET. One concern when doing this,
though, is that the fast turn-off time of the fan drive
MOSFET can cause a problem. The fan motor looks
like an inductor. When the MOSFET is turned off
quickly, the current in the fan wants to continue to flow
in the same direction. This causes the voltage at the
drain of the MOSFET to rise. If there aren’t any clamp
diodes internal to the fan, this voltage can rise above
the drain-to-source voltage rating of the MOSFET. For
this reason, an external clamp diode is suggested. This
is shown in Figure 4-5.
EQUATION
V
VOLTAGE
MIN
V
(V) = (DC * 1.4) + 1.20
100
MIN
DC = Desired Duty Cycle
Example: If a minimum duty cycle of 40% is desired,
the V
voltage should be set to:
MIN
EXAMPLE 4-1:
V
(V) = (40 * 1.4) + 1.20
100
MIN
V
= 1.76V
MIN
2003 Microchip Technology Inc.
DS21756B-page 13
TC642B/TC647B
During a fan fault condition, the FAULT output will
remain low until the fault condition has been removed.
During this time, the V
output is driven high contin-
OUT
uously to attempt to restart the fan, and the SENSE pin
is monitored for fan pulses. If a minimum of 16 pulses
are detected at the SENSE input over a 32 cycle time
Clamp Diode
FAN
period (one second for C = 1.0 µF), the fan fault con-
F
dition no longer exists. The FAULT output is then
released and the V
output returns to normal PWM
OUT
operation, as dictated by the V and V
inputs.
MIN
IN
Q
1
V
OUT
If the V
voltage is pulled below the V
level dur-
MIN
SHDN
ing a fan fault condition, the FAULT output will be
released and the V output will be shutdown
OUT
(V
= 0V). If the V
REL
voltage then increases above
MIN
R
OUT
SENSE
the V
threshold, the device will go through the
normal start-up routine.
If, during a fan fault condition, the voltage at the V pin
IN
drops below the V
voltage level, the TC642B/
GND
MIN
TC647B device will continue to hold the FAULT line low
and drive the V output to 100% duty cycle. If the fan
Q : N-Channel MOSFET
1
OUT
fault condition is then removed, the FAULT output will
be released and the V output will be driven to the
FIGURE 4-5:
Clamp Diode for Fan.
OUT
duty cycle that is being commanded by the V
input.
MIN
4.7
FAULT Output
The sink current capability of the FAULT output is listed
in the “Electrical Characteristics” table of Section 1.0.
The FAULT output is an open-drain, active-low output.
For the TC642B and TC647B devices, the FAULT out-
put indicates when a fan fault condition has occurred.
For the TC642B device, the FAULT output also indi-
cates when an over-temperature (OTF) condition has
occurred.
4.8
Sensing Fan Operation (SENSE)
The SENSE input is an analog input used to monitor
the fan’s operation. It does this by sensing fan current
pulses, which represent fan rotation. When a fan
rotates, commutation of the fan current occurs as the
fan poles pass the armatures of the motor. The commu-
tation of the fan current makes the current waveshape
appear as pulses. There are two typical current wave-
forms of brushless DC fan motors. These are shown in
Figures 4-6 and 4-7.
For the TC642B device, an over-temperature condition
is indicated (FAULT output is pulled low) when the V
IN
OTF
input reaches the V
threshold voltage (the V
OTF
threshold voltage is typically 20 mV higher than the
V
threshold and has 80 mV of hysteresis). This
CMAX
indicates that maximum cooling capacity has been
reached (the fan is at full speed) and that an overheat-
ing situation can occur. When the voltage at the V
IN
input falls below the V
teresis value (V
threshold voltage by the hys-
OTF
), the FAULT output returns to
OTF-HYS
the high-state (a pull-up resistor is needed on the
FAULT output).
A fan fault condition is indicated when fan current
pulses are no longer detected at the SENSE pin.
Pulses at the SENSE pin indicate that the fan is
spinning and conducting current.
If pulses are not detected at the SENSE pin for 32 PWM
cycles, the 3-cycle diagnostic timer is fired. This means
that the V
output is high for 3 PWM cycles. If pulses
OUT
are detected in this 3-cycle period, then normal PWM
operation is resumed and no fan fault is indicated. If no
pulses are detected in the 3-cycle period, the start-up
timer is activated and the V
output is driven high for
OUT
32 PWM cycles. If pulses are detected during this time-
frame, normal PWM operation is resumed. If no pulses
are detected during this time frame, a fan fault condition
exists and the FAULT output is pulled low.
FIGURE 4-6:
Fan Current With DC Offset
And Positive Commutation Current.
DS21756B-page 14
2003 Microchip Technology Inc.
TC642B/TC647B
.
across R
and presents only the voltage pulse
SENSE
portion to the SENSE pin of the TC642B/TC647B
devices.
The R
and C
values need to be selected so
SENSE
SENSE
that the voltage pulse provided to the SENSE pin is
70 mV (typical) in amplitude. Be sure to check the
sense pulse amplitude over all operating conditions
(duty cycles), as the current pulse amplitude will vary
with duty cycle. See Section 5.0, “Applications Informa-
tion”, for more details on selecting values for R
SENSE
and C
.
SENSE
Key features of the SENSE pin circuitry are an initial
blanking period after every V
pulse blanker.
pulse and an initial
OUT
The TC642B/TC647B sense circuitry has a blanking
period that occurs at the turn-on of each V pulse.
OUT
During this blanking period, the sense circuitry ignores
any pulse information that is seen at the SENSE pin
input. This stops the TC642B/TC647B device from
falsely sensing a current pulse which is due to the fan
drive device turn-on.
FIGURE 4-7:
Fan Current With
Commutation Pulses To Zero.
The SENSE pin senses positive voltage pulses that
have an amplitude of 70 mV (typical value). When a
pulse is detected, the missing pulse detector timer is
reset. As previously stated, if the missing pulse detec-
tor timer reaches the time for 32 cycles, the loop for
diagnosing a fan fault is engaged (diagnostic timer,
then the start-up timer).
Both of the fan current waveshapes that are shown in
Figures 4-6 and 4-7 can be sensed with the sensing
scheme shown in Figure 4-8.
The initial pulse blanker is also implemented to stop
false sensing of fan current pulses. When a fan is in a
locked rotor condition, the fan current no longer com-
mutates, it simply flows through one fan winding and is
a DC current. When a fan is in a locked rotor condition
and the TC642B/TC647B device is in PWM mode, it
will see one current pulse each time the V
output is
OUT
turned on. The initial pulse blanker allows the TC642B/
TC647B device to ignore this pulse and recognize that
the fan is in a fault condition.
4.9
Behavioral Algorithms
The behavioral algorithm for the TC642B/TC647B
devices is shown in Figure 4-9.
FAN
The behavioral algorithm shows the step-by-step deci-
sion-making process for the fan speed controller oper-
ation. The TC642B and TC647B devices are very
similar with one exception: the TC647B device does
not implement the over-temperature portion of the
algorithm.
TC64XB
R
ISO
V
OUT
SENSE
GND
C
SENSE
R
SENSE
(0.1 µF typical)
FIGURE 4-8:
Sensing Scheme For Fan
generates a
Current.
The fan current flowing through R
SENSE
voltage that is proportional to the current. The C
SENSE
capacitor removes any DC portion of the voltage
2003 Microchip Technology Inc.
DS21756B-page 15
TC642B/TC647B
Normal
Power-Up
Operation
Power-on
Reset
Clear Missing
Pulse Detector
FAULT = 1
Yes
?
Shutdown
VMIN < VSHDN
V
OUT = 0
Yes
Shutdown
OUT = 0
VMIN < VSHDN
No
?
V
No
VMIN > VREL
Yes
?
No
No
VMIN > VREL
?
Yes
Fire Start-up
Timer
(1 sec)
Yes
FAULT = 0
Power-Up
VIN > VOTF
?
Fire Start-up
Timer
No
Fan Pulse
Detected?
(1 sec)
Yes
No
Yes
Fan Pulse
Detected?
TC642B Only
VOUT
Proportional to Greater
Normal
of VIN or VMIN
No
Operation
Fan Fault
Yes
Fan Pulse
Detected?
No
M.P.D.
Expired?
Yes
No
Fire
Diagnostic
Timer
(100 msec)
Fire Start-up
Yes
No
Fan Pulse
Detected?
Fan Fault
Timer
(1 sec)
FAULT = Low,
OUT = High
Yes
V
Fan Pulse
Detected?
No
Yes
Shutdown
Fan Fault
VMIN<VSHDN
?
V
OUT = 0
No
Yes
No
V
MIN > VREL?
Power-Up
No
16 Pulses
Detected?
Yes
Normal
Operation
FIGURE 4-9:
TC642B/TC647B Behavioral Algorithm.
DS21756B-page 16
2003 Microchip Technology Inc.
TC642B/TC647B
5.0
5.1
APPLICATIONS INFORMATION
Setting the PWM Frequency
V
DD
I
DIV
The PWM frequency of the V
output is set by the
OUT
capacitor value attached to the C pin. The PWM fre-
F
quency will be 30 Hz (typical) for a 1 µF capacitor. The
relationship between frequency and capacitor value is
linear, making alternate frequency selections easy.
R
R
R
T
1
V
IN
As stated in previous sections, the PWM frequency
should be kept in the range of 15 Hz to 35 Hz. This will
eliminate the possibility of having audible frequencies
when varying the duty cycle of the fan drive.
2
A very important factor to consider when selecting the
PWM frequency for the TC642B/TC647B devices is the
RPM rating of the selected fan and the minimum duty
cycle that the fan will be operating at. For fans that have
a full speed rating of 3000 RPM or less, it is desirable
to use a lower PWM frequency. A lower PWM fre-
quency allows for a longer time period to monitor the
fan current pulses. The goal is to be able to monitor at
least two fan current pulses during the on time of the
FIGURE 5-1:
Temperature Sensing
Circuit.
Figure 5-1 represents a temperature-dependent volt-
age divider circuit. R is a conventional NTC thermistor,
T
while R and R are standard resistors. R and R form
1
2
1
T
a parallel resistor combination that will be referred to as
(R = R * R / R + R ). As the temperature
R
TEMP
TEMP
1
T
1
T
V
output.
increases, the value of R decreases and the value of
OUT
t
R
IN
will decrease with it. Accordingly, the voltage at
TEMP
Example: The system design requirement is to operate
the fan at 50% duty cycle when ambient temperatures
are below 20°C. The fan full speed RPM rating is
3000 RPM and has four current pulses per rotation. At
50% duty cycle, the fan will be operating at
approximately 1500 RPM.
V
increases as temperature increases, giving the
desired relationship for the V input. R helps to linear-
IN
1
ize the response of the sense network and aids in
obtaining the proper V voltages over the desired tem-
IN
perature range. An example of this is shown in
Figure 5-2.
If less current draw from V is desired, a larger value
EQUATION
DD
thermistor should be chosen. The voltage at the V pin
IN
60 × 1000
can also be generated by a voltage output temperature
Time for one revolution (msec.) = ----------------------- = 40
1500
sensor device. The key is to get the desired V voltage
IN
to system (or component) temperature relationship.
If one fan revolution occurs in 40 msec, each fan pulse
occurs 10 msec apart. In order to detect two fan current
The following equations apply to the circuit in
Figure 5-1.
pulses, the on time of the V
pulse must be at least
OUT
20 msec. With the duty cycle at 50%, the total period of
one cycle must be at least 40 msec, which makes the
PWM frequency 25 Hz. For this example, a PWM fre-
quency of 20 Hz is recommended. This would define a
EQUATION
V
DD × R2
V(T1) = -----------------------------------------
TEMP(T1) + R2
R
C capacitor value of 1.5 µF.
F
V
DD × R2
V(T2) = -----------------------------------------
TEMP(T2) + R2
5.2
Temperature Sensor Design
R
As discussed in previous sections, the V analog input
IN
has a range of 1.20V to 2.60V (typical), which repre-
In order to solve for the values of R and R , the values
1
2
sents a duty cycle range on the V
output of 0% to
OUT
for V , and the temperatures at which they are to
IN
100%, respectively. The V voltages can be thought of
IN
occur, need to be selected. The variables T1 and T2
represent the selected temperatures. The value of the
thermistor at these two temperatures can be found in
the thermistor data sheet. With the values for the ther-
as representing temperatures. The 1.20V level is the
low temperature at which the system requires very little
cooling. The 2.60V level is the high temperature, for
which the system needs maximum cooling capability
(100% fan speed).
mistor and the values for V , there are now two
IN
equations from which the values for R and R can be
1
2
One of the simplest ways of sensing temperature over
a given range is to use a thermistor. By using an NTC
thermistor, as shown in Figure 5-1, a temperature
variant voltage can be created.
found.
2003 Microchip Technology Inc.
DS21756B-page 17
TC642B/TC647B
Example: The following design goals are desired:
5.4
FanSense Network
(R and C
)
SENSE
• Duty Cycle = 50% (V = 1.90 V) with
SENSE
IN
Temperature (T1) = 30°C
The FanSense Network (comprised of R
and
SENSE
• Duty Cycle = 100% (V = 2.60 V) with
IN
C
) allows the TC642B and TC647B devices to
SENSE
Temperature (T2) = 60°C
detect commutation of the fan motor. R
converts
SENSE
Using a 100 kΩ thermistor (25°C value), look up the
thermistor values at the desired temperatures:
the fan current into a voltage. C
AC couples this
SENSE
voltage signal to the SENSE pin. The goal of the sense
network is to provide a voltage pulse to the SENSE pin
that has a minimum amplitude of 90 mV. This will
ensure that the current pulse caused by the fan
commutation is recognized by the TC642B/TC647B
device.
• R (T1) = 79428Ω @ 30°C
T
• R (T2) = 22593Ω @ 60°C
T
Substituting these numbers into the given equations
produces the following numbers for R and R .
1
2
• R = 34.8 kΩ
A 0.1 µF ceramic capacitor is recommended for
1
C
. Smaller values will require that larger sense
• R = 14.7 kΩ
SENSE
2
resistors be used. Using a 0.1 µF capacitor results in
reasonable values for R
typical SENSE network.
. Figure 5-3 illustrates a
SENSE
140
120
100
80
4.000
3.500
3.000
2.500
2.000
1.500
1.000
0.500
0.000
VIN Voltage
FAN
60
NTC Thermistor
100 k: @ 25ºC
RISO
715 Ω
40
VOUT
20
RTEMP
0
20
30
40
50
60
70
80
90 100
Temperature (ºC)
SENSE
CSENSE
(0.1 µF typical)
RSENSE
FIGURE 5-2:
IN
How Thermistor Resistance,
Vary With Temperature.
TEMP
V , and R
Note: See Table 5-1 for RSENSE values.
Figure 5-2 graphs R , R
(R in parallel with R )
1 T
T
TEMP
and V versus temperature for the example shown
IN
FIGURE 5-3:
Typical Sense Network.
will change with the cur-
above.
The required value of R
SENSE
5.3
Thermistor Selection
rent rating of the fan and the fan current waveshape. A
key point is that the current rating of the fan specified
by the manufacturer may be a worst-case rating, with
the actual current drawn by the fan being lower. For the
As with any component, there are a number of sources
for thermistors. A listing of companies that manufacture
thermistors can be found at www.temperatures.com/
thermivendors.html. This website lists over forty
suppliers of thermistor products. A brief list is shown
here.
purposes of setting the value for R
, the operating
SENSE
fan current should be measured to get the nominal
value. This can be done by using an oscilloscope cur-
rent probe or by using a voltage probe with a low value
resistor (0.5Ω). Another good tool for this exercise is
the TC642 Evaluation Board. This board allows the
®
- Thermometrics
- Quality Thermistor™
- Sensor Scientific™
®
- Ametherm
R
and C
values to be easily changed while
SENSE
SENSE
®
- U.S. Sensors™
- Advanced Thermal
Products™
- Vishay
allowing the voltage waveforms to be monitored to
ensure the proper levels are being reached.
®
- muRata
Table 5-1 shows values of R
according to the
SENSE
nominal operating current of the fan. The fan currents
are average values. If the fan current falls between two
of the values listed, use the higher resistor value.
DS21756B-page 18
2003 Microchip Technology Inc.
TC642B/TC647B
Another important factor to consider when selecting the
SENSE
TABLE 5-1:
FAN CURRENT VS. R
SENSE
R
value is the fan current value during a locked
Nominal Fan Current
rotor condition. When a fan is in a locked rotor condition
(fan blades are stopped even though power is being
applied to the fan), the fan current can increase dra-
matically, often 2.5 to 3.0 times the normal operating
fan current. This will effect the power rating of the
R
(Ω)
SENSE
(mA)
50
9.1
4.7
3.0
2.4
2.0
1.8
1.5
1.3
1.2
1.0
100
150
200
250
300
350
400
450
500
R
resistor selected.
SENSE
When selecting the fan for the application, the current
draw of the fan during a locked rotor condition should
be considered, especially if multiple fans are being
used in the application.
There are two main types of fan designs when looking
at fan current draw during a locked rotor condition.
The first is a fan that will simply draw high DC currents
when put into a locked rotor condition. Many older fans
were designed this way. An example of this is a fan that
draws an average current of 100 mA during normal
operation. In a locked rotor condition, this fan will draw
250 mA of average current. For this design, the
The values listed in Table 5-1 are for fans that have the
fan current waveshape shown in Figure 4-7. With this
waveshape, the average fan current is closer to the
peak value, which requires the resistor value to be
higher. When using a fan that has the fan current wave-
shape shown in Figure 4-6, the resistor value can often
be decreased since the current peaks are higher than
the average and it is the AC portion of the voltage that
gets coupled to the SENSE pin.
R
power rating must be sized to handle the
SENSE
250 mA condition. The fan bias supply must also take
this into account.
The second style design, which represents many of the
newer fan designs today, acts to limit the current in a
locked rotor condition by going into a pulse mode of
operation. An example of the fan current waveshape
for this style fan is shown in Figure 5-5. The fan repre-
The key point when selecting an R
value is to try
SENSE
to minimize the value in order to minimize the power
dissipation in the resistor. In order to do this, it is critical
to know the waveshape of the fan current and not just
the average value.
®
sented in Figure 5-5 is a Panasonic , 12V, 220 mA fan.
During the on time of the waveform, the fan current is
peaking up to 550 mA. Due to the pulse mode opera-
tion, however, the actual RMS current of the fan is very
near the 220 mA rating. Because of this, the power rat-
Figure 5-4 shows some typical waveforms for the fan
current and the voltage at the SENSE pin.
ing for the R
resistor does not have to be over-
SENSE
sized for this application.
FIGURE 5-4:
Typical Fan Current and
SENSE Pin Waveforms.
2003 Microchip Technology Inc.
DS21756B-page 19
TC642B/TC647B
FIGURE 5-5:
Fan Current During a Locked Rotor Condition.
The following is recommended:
5.5
Output Drive Device Selection
• Ask how the fan is designed. If the fan has clamp
diodes internally, this problem will not be seen. If
the fan does not have internal clamp diodes, it is a
good idea to put one externally (Figure 5-6). Put-
The TC642B/TC647B is designed to drive an external
NPN transistor or N-channel MOSFET as the fan
speed modulating element. These two arrangements
are shown in Figure 5-7. For lower current fans, NPN
transistors are a very economical choice for the fan
drive device. It is recommended that, for higher current
fans (300 mA and above), MOSFETs be used as the
fan drive device. Table 5-2 provides some possible part
numbers for use as the fan drive element.
ting a resistor between V
and the gate of the
OUT
MOSFET will also help slow down the turn-off and
limit this condition.
When using a NPN transistor as the fan drive element,
a base current-limiting resistor must be used, as is
shown in Figure 5-7.
FAN
When using MOSFETs as the fan drive element, it is
very easy to turn the MOSFETs on and off at very high
rates. Because the gate capacitances of these small
MOSFETs are very low, the TC642B/TC647B can
charge and discharge them very quickly, leading to
very fast edges. Of key concern is the turn-off edge of
the MOSFET. Since the fan motor winding is essentially
an inductor, once the MOSFET is turned off, the current
that was flowing through the motor wants to continue to
flow. If the fan does not have internal clamp diodes
around the windings of the motor, there is no path for
this current to flow through, and the voltage at the drain
of the MOSFET may rise until the drain-to-source rating
of the MOSFET is exceeded. This will most likely cause
the MOSFET to go into avalanche mode. Since there is
very little energy in this occurrence, it will probably not
fail the device, but it would be a long-term reliability
issue.
Q
1
V
OUT
R
SENSE
GND
Q : N-Channel MOSFET
1
FIGURE 5-6:
Clamp Diode For Fan Turn-
Off.
DS21756B-page 20
2003 Microchip Technology Inc.
TC642B/TC647B
Fan Bias
FAN
Fan Bias
FAN
RBASE
VOUT
Q1
Q1
VOUT
RSENSE
RSENSE
GND
GND
a) Single Bipolar Transistor
b) N-Channel MOSFET
FIGURE 5-7:
Output Drive Device Configurations.
TABLE 5-2:
Device
FAN DRIVE DEVICE SELECTION TABLE (NOTE 2)
Max Vbe sat /
V
/V
Fan Current
(mA)
Suggested
CE DS
Package
Min hfe
Vgs(V)
(V)
Rbase (Ω)
MMBT2222A
MPS2222A
MPS6602
SI2302
MGSF1N02E
SI4410
SOT-23
TO-92
TO-92
SOT-23
SOT-23
SO-8
1.2
1.2
1.2
2.5
2.5
4.5
4.5
50
50
50
NA
NA
NA
NA
40
40
40
20
20
30
60
150
150
500
500
500
1000
500
800
800
301
Note 1
Note 1
Note 1
Note 1
SI2308
SOT-23
Note 1: A series gate resistor may be used in order to control the MOSFET turn-on and turn-off times.
2: These drive devices are suggestions only. Fan currents listed are for individual fans.
5.6
Bias Supply Bypassing and Noise
Filtering
5.7
Design Example/Typical
Application
The bias supply (V ) for the TC642B/TC647B devices
The system has been designed with the following
DD
should be bypassed with a 1.0 µF ceramic capacitor.
This capacitor will help supply the peak currents that
are required to drive the base/gate of the external fan
drive devices.
components and criteria.
System inlet air ambient temperature ranges from 0ºC
to 50ºC. At 20ºC and below, it is desired to have the
system cooling stay at a constant level. At 20ºC, the fan
should be run at 40% of its full fan speed. Full fan
speed should be reached when the ambient air is 40ºC.
As the V pin controls the duty cycle in a linear fashion,
IN
any noise on this pin can cause duty-cycle jittering. For
this reason, the V pin should be bypassed with a
IN
The system has a surface mount, NTC-style thermistor
in a 1206 package. The thermistor is mounted on a
daughtercard, which is directly in the inlet air stream.
The thermistor is a NTC, 100 kΩ @ 25ºC, Thermomet-
0.01 µF capacitor.
In order to keep fan noise off of the TC642B/TC647B
device ground, individual ground returns for the
TC642B/TC647B and the low side of the fan current
sense resistor should be used.
®
rics part number NHQ104B425R5. The given Beta for
the thermistor is 4250. The system bias voltage to run
the fan controller is 5V and the fan voltage is 12V.
2003 Microchip Technology Inc.
DS21756B-page 21
TC642B/TC647B
The fan used in the system is a Panasonic , Panaflo -
series fan, model number FBA06T12H.
®
®
A fault indication is desired when the fan is in a locked
rotor condition. This signal is used to indicate to the
system that cooling is not available and a warning
should be issued to the user. No fault indication from
the fan controller is necessary for an over-temperature
condition, as this is being reported elsewhere.
Step 1: Gathering Information.
The first step in the design process is to gather the
needed data on the fan and thermistor. For the fan, it is
also a good idea to look at the fan current waveform, as
indicated earlier in the data sheet.
Fan Information: Panasonic number: FBA06T12H
- Voltage = 12V
- Current = 145 mA (number from data sheet )
FIGURE 5-9:
FBA06T12H Locked rotor
fan current.
From Figure 5-9 it is seen that in a locked-rotor fault
condition, the fan goes into a pulsed current mode of
operation. During this mode, when the fan is conduct-
ing current, the peak current value is 360 mA for peri-
ods of 200 msec. This is significantly higher than the
average full fan speed current shown in Figure 5-8.
However, because of the pulse mode, the average fan
current in a locked-rotor condition is lower and was
measured at 68 mA. The RMS current during this
mode, which is necessary for current sense resistor
(R
) value selection, was measured at 154 mA.
SENSE
This is slightly higher than the RMS value during full fan
speed operation.
Thermistor Information: Thermometrics part number:
FIGURE 5-8:
FBA06T12H fan current
NHQ104B425R5
waveform.
Resistance Value: 100 kΩ @ 25ºC
From the waveform in Figure 5-8, the fan current has
Beta Value (β): 4250
an average value of 120 mA, with peaks up to 150 mA.
From this information, the thermistor values at 20ºC
and 40ºC must be found. This information is needed in
This information will help in the selection of the R
SENSE
and C
values later on. Also of interest for the
SENSE
order to select the proper resistor values for R and R
1
2
R
selection value is what the fan current does in
SENSE
(see Figure 5-13), which sets the V voltage.
IN
a locked-rotor condition.
The equation for determining the thermistor values is
shown below:
EQUATION
β(TO – T)
RT = RTO exp ------------------------
T ² TO
R
is the thermistor value at 25ºC. T is 298.15 and T
0
T0
is the temperature of interest. All temperatures are
given in degrees kelvin.
Using this equation, the values for the thermistor are
found to be:
- R (20ºC) = 127,462Ω
T
- R (40ºC) = 50,520Ω
T
DS21756B-page 22
2003 Microchip Technology Inc.
TC642B/TC647B
Step 2: Selecting the Fan Controller.
Using standard 1% resistor values, the selected R and
2
1
R values are:
The requirements for the fan controller are that it have
minimum speed capability at 20ºC and also indicate a
fan fault condition. No over-temperature indication is
necessary. Based on these specifications, the proper
selection is the TC647B device.
- R = 237 kΩ
1
- R = 45.3 kΩ
2
A graph of the V voltage, thermistor resistance and
IN
R
resistance versus temperature for this
TEMP
Step 3: Setting the PWM Frequency.
configuration is shown in Figure 5-10.
The fan is rated at 4200 RPM with a 12V input. Since
the goal is to run to a 40% duty cycle (roughly 40% fan
speed), which equates to approximately 1700 RPM,
we can assume one full fan revolution occurs every
35 msec. The fan being used is a four-pole fan that
gives four current pulses per revolution. Knowing this
and viewing test results at 40% duty cycle, two fan cur-
rent pulses were always seen during the PWM on time
400
350
5.00
4.50
4.00
3.50
3.00
2.50
2.00
1.50
1.00
0.50
0.00
VIN
300
250
200
150
NTC Thermistor
with a PWM frequency of 30 Hz. For this reason, the C
F
100 k: @ 25ºC
100
value is selected to be 1.0 µF.
50
RTEMP
Step 4: Setting the V Voltage.
IN
0
From the design criteria, the desired duty cycle at 20ºC
0
10
20
30
40
50
60
70
80
90
is 40%, while full fan speed should be reached at 40ºC.
Temperature (ºC)
Based on a V voltage range of 1.20V to 2.60V, which
IN
represents 0% to 100% duty cycle, the 40% duty cycle
voltage can be found using the following equation:
FIGURE 5-10:
Thermistor Resistance, V ,
IN
and R vs. Temperature.
TEMP
Step 5: Setting the Minimum Speed Voltage (V ).
MIN
EQUATION
Setting the voltage for the minimum speed is accom-
plished using a simple resistor voltage divider. The cri-
teria for the voltage divider in this design is that it draw
no more than 100 µA of current. The required minimum
speed voltage was determined earlier in the selection
V
= (DC * 1.4V) + 1.20V
IN
DC = Desired Duty Cycle
Using the above equation, the
calculated to be:
- V (40%) = 1.76V
V
values are
IN
of the V voltage at 40% duty cycle, since this was also
IN
set at the temperature which minimum speed is to
occur (20ºC).
IN
- V (100%) = 2.60V
IN
- V
= 1.76V
MIN
Using these values in combination with the thermistor
Given this desired setpoint, and knowing the desired
resistance values calculated earlier, the R and R
1
2
divider current, the following equations can be used to
resistor values can now be calculated using the
following equation:
solve for the resistor values for R and R :
3
4
EQUATION
EQUATION
5V
R3 + R4
V
DD × R2
V(T1) = -----------------------------------------
TEMP(T1) + R2
I
=
DIV
R
5V*R
R3 + R4
V
DD × R2
V(T2) = -----------------------------------------
TEMP(T2) + R2
4
V
=
MIN
R
Using the equations above, the resistor values for R
3
R
is the parallel combination of R and the ther-
1
TEMP
and R are found to be:
4
mistor. V(T1) represents the V voltage at 20ºC and
IN
- R = 32.4 kΩ
V(T2) represents the V voltage at 40ºC. Solving the
3
IN
equations simultaneously yields the following values
- R = 17.6 kΩ
4
(V = 5V):
DD
- R = 238,455Ω
1
- R = 45,161Ω
2
2003 Microchip Technology Inc.
DS21756B-page 23
TC642B/TC647B
.
Using standard 1% resistor values yields the following
values:
- R = 32.4 kΩ
3
- R = 17.8 kΩ
4
Step 6: Selecting the Fan Drive Device (Q ).
1
Since the fan operating current is below 200 mA, a
transistor or MOSFET can be used as the fan drive
device. In order to reduce component count and cur-
rent draw, the drive device for this design is chosen to
be a N-channel MOSFET. Selecting from Table 5-2,
there are two MOSFETs that are good choices: the
MGSF1N02E and the SI2302. These devices have the
same pinout and are interchangeable for this design.
FIGURE 5-12:
SENSE pin voltage with
Step 7: Selecting the R
and C
Values.
SENSE
SENSE
3.0Ω sense resistor.
The goal again for selecting these values is to ensure
that the signal at the SENSE pin is 90 mV in amplitude
under all operating conditions. This will ensure that the
pulses are detected by the TC642B/TC647B device
and that the fan operation is detected.
Since the 3.0Ω value of sense resistor provides the
proper voltage to the SENSE pin, it is the correct choice
for this solution as it will also provide the lowest power
dissipation and the most voltage to the fan. Using the
RMS fan current that was measured previously, the
The fan current waveform is shown in Figure 5-8 and,
as discussed previously, with a waveform of this shape,
the current sense resistor values shown in Table 5-1 are
good reference values. Given that the average fan oper-
ating current was measured to be 120 mA, this falls
between two of the values listed in the table. For refer-
ence purposes, both values have been tested and
these results are shown in Figures 5-11 (4.7Ω) and 5-12
power dissipation in the resistor during a fan fault con-
2
dition is 71 mW (Irms * R
). This number will set
SENSE
the wattage rating of the resistor that is selected. The
selected value will vary depending upon the derating
guidelines that are used.
Now that all the values have been selected, the sche-
matic representation of this design can be seen in
Figure 5-13.
(3.0Ω). The selected C
value is 0.1 µF as this pro-
SENSE
vides the appropriate coupling of the voltage to the
SENSE pin.
.
FIGURE 5-11:
SENSE pin voltage with
4.7Ω sense resistor.
DS21756B-page 24
2003 Microchip Technology Inc.
TC642B/TC647B
+5V
+12V
+
C
VDD
®
Thermometrics
R
1.0 µF
1
100 kΩ @25°C
237 kΩ
®
NHQ104B425R5
Panasonic
Fan
8
V
12V, 140 mA
FBA06T12H
R
5
1
V
10 kΩ
IN
DD
C
B
0.01 µF
6
FAULT
R
2
45.3 kΩ
+5V
R
Q
7
5
3
1
V
TC647B
OUT
SI2302
or
32.4 kΩ
3
MGSF1N02E
V
MIN
C
B
SENSE
0.01 µF
2
C
R
SENSE
4
C
F
R
0.1 µF
SENSE
17.8 kΩ
GND
4
3.0Ω
C
F
1.0 µF
FIGURE 5-13:
Bypass capacitor C
Design Example Schematic.
is added to the design to
VDD
decouple the bias voltage. This is good to have, espe-
cially when using a MOSFET as the drive device. This
helps to give a localized low-impedance source for the
current required to charge the gate capacitance of Q .
1
Two other bypass capacitors, labeled as C , were also
B
added to decouple the V and V
nodes. These
MIN
IN
were added simply to remove any noise present that
might cause false triggerings or PWM jitter. R is the
5
pull-up resistor for the FAULT output. The value for this
resistor is system-dependent.
2003 Microchip Technology Inc.
DS21756B-page 25
TC642B/TC647B
6.0
6.1
PACKAGING INFORMATION
Package Marking Information
8-Lead PDIP (300 mil)
Example:
XXXXXXXXX
NNN
TC642BCPA
025
YYWW
0215
8-Lead SOIC (150 mil)
Example:
XXXXXX
TC642B
XXXYYWW
COA0215
NNN
025
Example:
8-Lead MSOP
TC642B
XXXXXX
YWWNNN
215025
Legend: XX...X Customer specific information*
Y
Year code (last digit of calendar year)
YY
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
WW
NNN
Note: 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 device marking consists of Microchip part number, year code, week code, and traceability
code.
DS21756B-page 26
2003 Microchip Technology Inc.
TC642B/TC647B
8-Lead Plastic Dual In-line (P) – 300 mil (PDIP)
E1
D
2
n
1
α
E
A2
A
L
c
A1
β
B1
B
p
eB
Units
Dimension Limits
INCHES*
NOM
MILLIMETERS
MIN
MAX
MIN
NOM
MAX
n
p
A
A2
A1
E
E1
D
L
c
B1
B
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
8
8
.100
.155
.130
2.54
3.94
3.30
.140
.170
.145
3.56
4.32
3.68
.115
.015
.300
.240
.360
.125
.008
.045
.014
.310
5
2.92
0.38
7.62
6.10
9.14
3.18
0.20
1.14
0.36
7.87
5
.313
.250
.373
.130
.012
.058
.018
.370
10
.325
.260
.385
.135
.015
.070
.022
.430
15
7.94
6.35
9.46
3.30
0.29
1.46
0.46
9.40
10
8.26
6.60
9.78
3.43
0.38
1.78
0.56
10.92
15
§
eB
α
β
5
10
15
5
10
15
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MS-001
Drawing No. C04-018
2003 Microchip Technology Inc.
DS21756B-page 27
TC642B/TC647B
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
A1
Units
INCHES*
NOM
MILLIMETERS
Dimension Limits
MIN
MAX
MIN
NOM
8
MAX
n
p
A
A2
A1
E
E1
D
h
L
f
Number of Pins
Pitch
Overall Height
8
.050
.061
.056
.007
.237
.154
.193
.015
.025
4
1.27
.053
.069
1.35
1.32
1.55
1.42
0.18
6.02
3.91
4.90
0.38
0.62
4
1.75
Molded Package Thickness
Standoff
.052
.004
.228
.146
.189
.010
.019
0
.061
.010
.244
.157
.197
.020
.030
8
1.55
0.25
6.20
3.99
5.00
0.51
0.76
8
§
0.10
5.79
3.71
4.80
0.25
0.48
0
Overall Width
Molded Package Width
Overall Length
Chamfer Distance
Foot Length
Foot Angle
c
Lead Thickness
Lead Width
.008
.013
0
.009
.017
12
.010
.020
15
0.20
0.33
0
0.23
0.42
12
0.25
0.51
15
B
α
β
Mold Draft Angle Top
Mold Draft Angle Bottom
0
12
15
0
12
15
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MS-012
Drawing No. C04-057
DS21756B-page 28
2003 Microchip Technology Inc.
TC642B/TC647B
8-Lead Plastic Micro Small Outline Package (MS) (MSOP)
E
E1
p
D
2
B
n
1
α
A2
A
c
φ
A1
(F)
L
β
Units
Dimension Limits
INCHES
NOM
MILLIMETERS*
MIN
MAX
MIN
NOM
MAX
n
p
Number of Pins
Pitch
8
8
.026 BSC
0.65 BSC
Overall Height
A
A2
A1
E
-
-
.043
-
-
1.10
Molded Package Thickness
Standoff
.030
.000
.033
-
.037
.006
0.75
0.00
0.85
-
0.95
0.15
Overall Width
.193 TYP.
4.90 BSC
Molded Package Width
Overall Length
Foot Length
E1
D
.118 BSC
.118 BSC
3.00 BSC
3.00 BSC
L
.016
.024
.037 REF
.031
0.40
0.60
0.95 REF
0.80
Footprint (Reference)
Foot Angle
F
φ
c
0°
.003
.009
5°
-
8°
.009
.016
15°
0°
0.08
0.22
5°
-
-
-
-
-
8°
0.23
0.40
15°
Lead Thickness
Lead Width
.006
B
α
β
.012
Mold Draft Angle Top
Mold Draft Angle Bottom
*Controlling Parameter
Notes:
-
-
5°
15°
5°
15°
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not
exceed .010" (0.254mm) per side.
JEDEC Equivalent: MO-187
Drawing No. C04-111
2003 Microchip Technology Inc.
DS21756B-page 29
TC642B/TC647B
6.2
Taping Form
Component Taping Orientation for 8-Pin MSOP Devices
User Direction of Feed
PIN 1
W
P
Standard Reel Component Orientation
for 713 or TR Suffix Device
Carrier Tape, Number of Components Per Reel and Reel Size:
Package
8-Pin MSOP
Carrier Width (W)
Pitch (P)
8 mm
Part Per Full Reel
Reel Size
13 in.
12 mm
2500
Component Taping Orientation for 8-Pin SOIC Devices
User Direction of Feed
PIN 1
W
P
Standard Reel Component Orientation
for 713 or TR Suffix Device
Carrier Tape, Number of Components Per Reel and Reel Size:
Package
8-Pin SOIC
Carrier Width (W)
Pitch (P)
Part Per Full Reel
Reel Size
12 mm
8 mm
2500
13 in.
DS21756B-page 30
2003 Microchip Technology Inc.
TC642B/TC647B
PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
Examples:
PART NO.
Device
X
/XX
a) TC642BEOA: SOIC package.
Temperature Package
Range
b) TC642BEOA713: Tape and Reel,
SOIC package.
c) TC642BEPA: PDIP package.
d) TC642BEUA: MSOP package.
Device:
TC642B: PWM Fan Speed Controller with Mini-
mum Fan Speed, Fan Restart, Fan Fault
Detection, and Over-Temp Detection.
TC647B: PWM Fan Speed Controller with Mini-
mum Fan Speed, Fan Restart, and Fan
Fault Detection.
a) TC647BEOA: SOIC package.
b) TC647BEPA: PDIP package.
c) TC647BEUA: MSOP package.
d) TC647BEUATR: Tape and Reel,
Temperature
Range:
E
= -40°C to +85°C
MSOP package.
Package:
OA = Plastic SOIC, (150 mil Body), 8-lead
PA = Plastic DIP (300 mil Body), 8-lead
UA = Plastic Micro Small Outline (MSOP), 8-lead
713 = Tape and Reel (SOIC and MSOP)
(TC642B only)
TR = Tape and Reel (SOIC and MSOP)
(TC647B only)
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. Your local Microchip sales office
2. The Microchip Corporate Literature Center U.S. FAX: (480) 792-7277
3. The Microchip Worldwide Site (www.microchip.com)
Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using.
Customer Notification System
Register on our web site (www.microchip.com/cn) to receive the most current information on our products.
2003 Microchip Technology Inc.
DS21756B-page 31
TC642B/TC647B
NOTES:
DS21756B-page 32
2003 Microchip Technology Inc.
Note the following details of the code protection feature on Microchip devices:
•
Microchip products meet the specification contained in their particular Microchip Data Sheet.
•
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
•
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip's Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
•
•
Microchip is willing to work with the customer who is concerned about the integrity of their code.
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
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, KEELOQ,
MPLAB, PIC, PICmicro, PICSTART, PRO MATE and
PowerSmart 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.
Accuron, Application Maestro, dsPIC, dsPICDEM,
dsPICDEM.net, ECONOMONITOR, FanSense, FlexROM,
fuzzyLAB, In-Circuit Serial Programming, ICSP, ICEPIC,
microPort, Migratable Memory, MPASM, MPLIB, MPLINK,
MPSIM, PICC, PICkit, PICDEM, PICDEM.net, PowerCal,
PowerInfo, PowerMate, PowerTool, rfLAB, rfPIC, Select
Mode, SmartSensor, SmartShunt, SmartTel 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.
© 2003, 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.
DS21756B-page 33
2003 Microchip Technology Inc.
M
WORLDWIDE SALES AND SERVICE
Japan
AMERICAS
ASIA/PACIFIC
Microchip Technology Japan K.K.
Benex S-1 6F
Corporate Office
Australia
2355 West Chandler Blvd.
Microchip Technology Australia Pty Ltd
Marketing Support Division
Suite 22, 41 Rawson Street
Epping 2121, NSW
3-18-20, Shinyokohama
Kohoku-Ku, Yokohama-shi
Kanagawa, 222-0033, Japan
Tel: 81-45-471- 6166 Fax: 81-45-471-6122
Chandler, AZ 85224-6199
Tel: 480-792-7200 Fax: 480-792-7277
Technical Support: 480-792-7627
Web Address: http://www.microchip.com
Australia
Korea
Tel: 61-2-9868-6733 Fax: 61-2-9868-6755
Atlanta
Microchip Technology Korea
168-1, Youngbo Bldg. 3 Floor
Samsung-Dong, Kangnam-Ku
Seoul, Korea 135-882
China - Beijing
3780 Mansell Road, Suite 130
Alpharetta, GA 30022
Microchip Technology Consulting (Shanghai)
Co., Ltd., Beijing Liaison Office
Unit 915
Tel: 770-640-0034 Fax: 770-640-0307
Tel: 82-2-554-7200 Fax: 82-2-558-5934
Boston
Bei Hai Wan Tai Bldg.
Singapore
2 Lan Drive, Suite 120
Westford, MA 01886
Tel: 978-692-3848 Fax: 978-692-3821
No. 6 Chaoyangmen Beidajie
Beijing, 100027, No. China
Tel: 86-10-85282100 Fax: 86-10-85282104
Microchip Technology Singapore Pte Ltd.
200 Middle Road
#07-02 Prime Centre
Chicago
China - Chengdu
Singapore, 188980
333 Pierce Road, Suite 180
Itasca, IL 60143
Microchip Technology Consulting (Shanghai)
Co., Ltd., Chengdu Liaison Office
Rm. 2401-2402, 24th Floor,
Tel: 65-6s334-8870 Fax: 65-6334-8850
Taiwan
Tel: 630-285-0071 Fax: 630-285-0075
Microchip Technology (Barbados) Inc.,
Taiwan Branch
Ming Xing Financial Tower
Dallas
No. 88 TIDU Street
4570 Westgrove Drive, Suite 160
Addison, TX 75001
11F-3, No. 207
Chengdu 610016, China
Tung Hua North Road
Taipei, 105, Taiwan
Tel: 86-28-86766200 Fax: 86-28-86766599
Tel: 972-818-7423 Fax: 972-818-2924
China - Fuzhou
Tel: 886-2-2717-7175 Fax: 886-2-2545-0139
Detroit
Microchip Technology Consulting (Shanghai)
Co., Ltd., Fuzhou Liaison Office
Unit 28F, World Trade Plaza
Tri-Atria Office Building
EUROPE
Austria
32255 Northwestern Highway, Suite 190
Farmington Hills, MI 48334
Tel: 248-538-2250 Fax: 248-538-2260
No. 71 Wusi Road
Microchip Technology Austria GmbH
Durisolstrasse 2
Fuzhou 350001, China
Kokomo
Tel: 86-591-7503506 Fax: 86-591-7503521
A-4600 Wels
2767 S. Albright Road
Kokomo, IN 46902
China - Hong Kong SAR
Austria
Microchip Technology Hongkong Ltd.
Unit 901-6, Tower 2, Metroplaza
223 Hing Fong Road
Tel: 43-7242-2244-399
Fax: 43-7242-2244-393
Denmark
Tel: 765-864-8360 Fax: 765-864-8387
Los Angeles
Kwai Fong, N.T., Hong Kong
18201 Von Karman, Suite 1090
Irvine, CA 92612
Microchip Technology Nordic ApS
Regus Business Centre
Lautrup hoj 1-3
Tel: 852-2401-1200 Fax: 852-2401-3431
China - Shanghai
Tel: 949-263-1888 Fax: 949-263-1338
Microchip Technology Consulting (Shanghai)
Co., Ltd.
Ballerup DK-2750 Denmark
Phoenix
Tel: 45-4420-9895 Fax: 45-4420-9910
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7966 Fax: 480-792-4338
Room 701, Bldg. B
France
Far East International Plaza
No. 317 Xian Xia Road
Microchip Technology SARL
Parc d’Activite du Moulin de Massy
43 Rue du Saule Trapu
San Jose
Shanghai, 200051
Microchip Technology Inc.
2107 North First Street, Suite 590
San Jose, CA 95131
Tel: 86-21-6275-5700 Fax: 86-21-6275-5060
Batiment A - ler Etage
China - Shenzhen
91300 Massy, France
Microchip Technology Consulting (Shanghai)
Co., Ltd., Shenzhen Liaison Office
Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79
Tel: 408-436-7950 Fax: 408-436-7955
Germany
Rm. 1812, 18/F, Building A, United Plaza
No. 5022 Binhe Road, Futian District
Shenzhen 518033, China
Toronto
Microchip Technology GmbH
Steinheilstrasse 10
6285 Northam Drive, Suite 108
Mississauga, Ontario L4V 1X5, Canada
Tel: 905-673-0699 Fax: 905-673-6509
D-85737 Ismaning, Germany
Tel: 49-89-627-144-0
Fax: 49-89-627-144-44
Tel: 86-755-82901380 Fax: 86-755-82966626
China - Qingdao
Rm. B505A, Fullhope Plaza,
Italy
No. 12 Hong Kong Central Rd.
Qingdao 266071, China
Microchip Technology SRL
Via Quasimodo, 12
20025 Legnano (MI)
Milan, Italy
Tel: 86-532-5027355 Fax: 86-532-5027205
India
Tel: 39-0331-742611 Fax: 39-0331-466781
Microchip Technology Inc.
India Liaison Office
United Kingdom
Marketing Support Division
Divyasree Chambers
Microchip Ltd.
505 Eskdale Road
1 Floor, Wing A (A3/A4)
No. 11, O’Shaugnessey Road
Bangalore, 560 025, India
Tel: 91-80-2290061 Fax: 91-80-2290062
Winnersh Triangle
Wokingham
Berkshire, England RG41 5TU
Tel: 44-118-921-5869 Fax: 44-118-921-5820
03/25/03
DS21756B-page 34
2003 Microchip Technology Inc.
相关型号：
TC647BEUATR
PWM Fan Speed Controllers With Minimum Fan Speed, Fan Restart and FanSense⑩ Technology for Fault Detection
MICROCHIP
©2020 ICPDF网 联系我们和版权申明