TC642
DS21444D-page 16 2001-2012 Microchip Technology Inc.
5.8 TC642 as a Microcontroller
Peripheral
In a system containing a microcontroller or other host
intelligence, the TC642 can be effectively managed as
a CPU peripheral. Routine fan control functions can be
performed by the TC642 without processor intervention.
The microcontroller receives temperature data from one
or more points throughout the system. It calculates a fan
operating speed based on an algorithm specifically
designed for the application at hand. The processor
controls fan speed using complementary port bits I/O1
through I/O3. Resistors R
1
through R
6
(5% tolerance)
form a crude 3-bit DAC that translates the 3-bit code
from the processor's outputs into a 1.6V DC control sig-
nal. 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 TC642 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/O0) can be used to reset
the TC642 following detection of a fault condition. The
FAULT
output can be connected to the processor's
interrupt input, or to an I/O pin, for polled operation.
FIGURE 5-10: TC642 as a Microcontroller Peripheral.
TC642
V
IN
C
F
V
MIN
GND
V
DD
V
OUT
FAULT
SENSE
(Optional)
(MSB)
R
1
110 kΩ
R
2
240 kΩ
R
3
360 kΩ
(LSB)
R
5
1.5 kΩ
+5V
R
6
1 kΩ
R
4
18 kΩ
R
7
33 kΩ
+5V
R
8
18 kΩ
C
B
.01 μF
+
1 μF
C
B
.01 μF
Fan
+12V
+5V
C
B
1 μF
+
800Ω
+5V
R
10
10 kΩ
0.1 μF
2N2222A
R
11
2.2Ω
1
2
3
4
5
6
7
8
(RESET)
CMOS
Microcontroller
+5V
Analog or Digital
Temperature
Data from one or
more Sensors
I/O0
I/O1
I/O2
I/O3
INT
GND
CMOS
Outputs
Open-drain
Outputs
R
9
2001-2012 Microchip Technology Inc. DS21444D-page 17
TC642
6.0 PACKAGING INFORMATION
6.1 Package Marking Information
XXXXXXXX
NNN
YYWW
8-Lead PDIP (300 mil)
Example:
8-Lead SOIC (150 mil)
Example:
XXXXXXXX
YYWW
NNN
TC642CPA
025
0215
TC642COA
0215
025
8-Lead MSOP
Example:
XXXXXX
YWWNNN
TC642E
215025
Legend: XX...X Customer specific information*
YY Year code (last 2 digits of calendar year)
WW Week code (week of January 1 is week ‘01’)
NNN Alphanumeric traceability code
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 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.
TC642
DS21444D-page 18 2001-2012 Microchip Technology Inc.
8-Lead Plastic Dual In-line (P) – 300 mil (PDIP)
B1
B
A1
A
L
A2
p
E
eB
c
E1
n
D
1
2
Units INCHES* MILLIMETERS
Dimension Limits MIN NOM MAX MIN NOM MAX
Number of Pins
n
88
Pitch
p
.100 2.54
Top to Seating Plane A .140 .155 .170 3.56 3.94 4.32
Molded Package Thickness
A2
.115 .130 .145 2.92 3.30 3.68
Base to Seating Plane A1 .015 0.38
Shoulder to Shoulder Width E .300 .313 .325 7.62 7.94 8.26
Molded Package Width E1 .240 .250 .260 6.10 6.35 6.60
Overall Length D .360 .373 .385 9.14 9.46 9.78
Tip to Seating Plane L .125 .130 .135 3.18 3.30 3.43
Lead Thickness
c
.008 .012 .015 0.20 0.29 0.38
Upper Lead Width B1 .045 .058 .070 1.14 1.46 1.78
Lower Lead Width B .014 .018 .022 0.36 0.46 0.56
Overall Row Spacing §
eB
.310 .370 .430 7.87 9.40 10.92
Mold Draft Angle Top
51015 51015
Mold Draft Angle Bottom
51015 51015
* Controlling Parameter
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
JEDEC Equivalent: MS-001
Drawing No. C04-018
.010” (0.254mm) per side.
§ Significant Characteristic
Note: For the most current package drawings, please see the Microchip Packaging Specification located
at http://www.microchip.com/packaging

TC642CPA

Mfr. #:
Manufacturer:
Microchip Technology
Description:
Motor / Motion / Ignition Controllers & Drivers w/Fault Dtct
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
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