TC647EOA Microchip Technology, TC647EOA Datasheet - Page 15

• Manufacturer Part Number: TC647EOA
• Description: IC PWM FAN SPEED CTRLR 8-SOIC
• Manufacturer: Microchip Technology
• Type: Controller - PWM Fanr

Specifications of TC647EOA

• Applications: Fan Controller, Brushless (BLDC)
• Number Of Outputs: 1
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Motor Type: PWM
• No. Of Outputs: 1
• Output Current: 5mA
• Output Voltage: 4.4V
• Supply Voltage Range: 3V To 5.5V
• Driver Case Style: SOIC
• No. Of Pins: 8
• Operating Temperature Range: -40°C To +85°C
• Product: Fan / Motor Controllers / Drivers
• Operating Supply Voltage: 3 V to 5.5 V
• Supply Current: 1 mA
• Mounting Style: SMD/SMT
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Voltage - Load: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

FIGURE 5-9:
5.8
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 R
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
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).
Fan Shutdown
2002 Microchip Technology Inc.
MIN
TC647 as a Microcontroller
Peripheral
set to 1.8V, the TC647 has a minimum
(Optional)
10 k
R 8
Design Example.
1
through R
+5V
Q 2
R 1
20.5 k
R 2
3.83 k
+5V
R 6
18 k
R 5
33 k
6
(5% tolerance)
@ 25 C
C
0.01 µF
C
0.01 µF
10 k
NTC
B
C 1
1 µF
B
1
3
2
C
V
V
C
1 µF
F
MIN
IN
B
+
+5V
V
DD
TC647
8
GND
4
SENSE
FAULT
V
OUT
6
7
5
C SENSE
System
0.1 µF
Fault
DS21447C-page 15
R 7
800
TC647
+12V
Fan
Q 1
R SENSE
2.2