Hall Sensor Interface - Motorola M68HC08 Manual

Hall Sensors
Connector
1
2
3
4
5
J1
C1 +
2u2/20V
GND
5.2.3 User's Interface and Bootloader
DRM046 — Rev 0
MOTOROLA
Freescale Semiconductor, Inc.
R41 and R42! This causes a short circuit between +12V
+5V rails.
DC
For brushless motors that use Hall sensor inputs for commutation, noise
immunity of the sensor inputs is a key design consideration. Noise on
these inputs can be particularly troublesome, since commutation to the
wrong state precludes smooth operation of the motor. To facilitate noise,
the sensor inputs are filtered with 1000-nsec single-pole filters, as shown
in Figure 5-4. Hall Sensor
resistors, in the order of 1 kΩ., provides an additional measure of noise
immunity.
+5V
R1
1k
+5V
R2
1k
GND
HS_A
+5V
HS_B
HS_C
R5
1k
C2 R41 0R
100nF
+12V
+5V
R42 0R
Figure 5-4. Hall Sensor Interface
The user interface enables controlling the drive. It is shown in
5-5. User's Interface. The speed can be set-up using a potentiometer,
- connected through a jumper to channel AD2 of the ADC. A small
ceramic capacitor C16 is inserted for signal filtering. The run/stop switch
Hardware Design
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Detailed Design Description
Interface. Using relatively low value pull-up
R3 220R
R4 220R
R6 220R
C5 C6
4n7 4n7
GND
Designer Reference Manual
Hardware Design
and
DC
PTB7
PTB6
PTA1
C7
4n7
Figure
39