AN2687 Freescale Semiconductor / Motorola, AN2687 Datasheet - Page 5

• Manufacturer Part Number: AN2687
• Description: BLDC Fan Control using the MC68HC908QT2
• Manufacturer: Freescale Semiconductor / Motorola

Hardware
Description
MOTOROLA
Interface
MON08
Thermal
Sensor
GND
12V
5V
module can be configured to generate PWM signals. Apart from the V
V
The BLDC fan control circuits use this 8-pin MC68HC908QT2 to provide the
following control features:
Figure 5
of the BLDC fan, Hall effect sensor, MC68HC908QT2 MCU, regulator,
transistors, thermal sensor, and buzzer.
SS
•
•
•
•
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Freescale Semiconductor, Inc.
Thermal-Speed
Regulator
Monitor Code
MC68HC908QT2
pins, the remaining six pins are multiplexed with the modules for I/O use.
ADC
BLDC Fan Control using the MC68HC908QT2
For More Information On This Product,
Table
Auto-thermal speed adjustment
Motor-lock protection
Over-temperature and motor-lock alarms
In-circuit programming for firmware upgrade (on evaluation demo)
Manual speed adjustment (on evaluation demo)
Figure 5. BLDC Fan Block Diagram
shows the block diagram of the BLDC fan control hardware. It consists
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Motor Locking Protection
Transistors
Speed Control
Commutation
Over-Temperature
and Motor Locking
Alarm
Position
PART 2: HARDWARE DESIGN
Hall Sensor
M
DD
AN2687/D
and
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