UM1943
Circuit description
DocID028304 Rev 1
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4.3
Analog section
– Hall/Encoder motor speed sensor
The X-NUCLEO-IHM07M1 expansion board implements the Hall/Encoder sensor detecting
circuit for speed measurement. The motor sensor pin, through the J3 connector and an
analog circuit, are connected to the STM32 Nucleo board in order to detect the motor spin;
a +5 V and GND are also provided for power supply of the sensors. For sensors that
require external pull-up, jumper JP3 is available (see figure below). For this setting please,
refer to
Table 1: "Jumper settings"
.
Figure 16: X-NUCLEO-IHM07M1
– hall/encoder sensor circuit
4.4
Analog section
– BEMF detection circuit
The X-NUCLEO-IHM07M1 expansion board provides two hardware solutions for motor
position measuring, one based on sensors (refer to
Section 4.3: "Analog section
–
Hall/Encoder motor speed sensor"
) and the other based on sensorless detection. In six-
step driving mode one of the three phases is left in high impedance state and comparing
the voltage of this phase with the center-tap voltage, we can detect the BEMF zero-
crossing. This signal is acquired with an analog circuit embedded on the board, as shown
in the diagram below.
Figure 17: X-NUCLEO-IHM07M1
– BEMF detection circuit
4.5
Analog section
– Bus voltage and temperature sensing
circuit
The X-NUCLEO-IHM07M1 expansion board provides the hardware for bus voltage sensing
and temperature measurement. This signal is acquired respectively with a resistor divider
HALL/ENCODER SENSOR
5V
GND
A+/H1
B+/H2
Z+/H3
3V3
3V3
5V
A+/H1
B+/H2
Z+/H3
R30
1k8
JP3
JUMPER
C20
10p
F
10
V
R32
1k8
R34
4K7 N.M.
R31
1k8
R33
4K7 N.M.
R29
10k
J3
Stripline m. 1x5
1
2
3
4
5
C22
10p
F
10
V
R28
10k
R27
10k
D4
BA
T
30K
F
IL
M
D3
BA
T
30K
F
IL
M
D2
BA
T
30K
F
IL
M
C19
100n
R35
4K7 N.M.
J4
RING
1
C21
10p
F
10
V
GSPG15092015DI0645
BEMF DETECTION - SIX STEP
OUT1
OUT2
OUT3
GPIO_BEMF
GPIO_BEMF
GPIO_BEMF
BEMF1
BEMF3
3V3
3V3
3V3
3V3
GPIO_BEMF
BEMF1
BEMF2
GPIO_BEMF
GPIO_BEMF
BEMF3
R39
10k
R36
2.2k
D10
BAT30KFILM
D6
BAT30KFILM
R41
10k
D9
BAT30KFILM
D5
BAT30KFILM
D8
BAT30KFILM
R38
2.2k
C23
0.1uF/6.3V
R40
10k
D7
BAT30KFILM
R37
2.2k
GSPG15092015DI0650
