Analog Section - STMicroelectronics X-NUCLEO-IHM07M1 User Manual

2.2

Analog section

2.2.1 Hall/Encoder motor speed sensor
The X-NUCLEO-IHM07M1
measurement. The motor sensor pins, through J3 connector and an analog circuit, are connected to the
Nucleo board to detect the motor spin; a +5 V and GND are also provided for the sensor power supply.
For sensors that require external pull-up, use JP3 jumper (refer to
HALL/ENCODER SENSOR
J3
A+/H1 1
B+/H2 2
Z+/H3 3
5V 4
GND 5
Stripline m. 1x5
J4
1
RING
2.2.2 BEMF detection circuit
The X-NUCLEO-IHM07M1
based on sensors (refer to
detection.
In six-step driving mode, one of the three phases is left in high impedance state. By comparing the voltage of this
phase to the center-tap voltage, you can detect the BEMF zero-crossing. This signal is acquired with an analog
circuit embedded on the board as shown below.
D5
3V3
BAT30KFILM
C23
0.1µF/6.3V
R39
OUT1
10k
UM1943 - Rev 2
expansion board implements the Hall/Encoder sensor detecting circuit for speed
Figure 8. X-NUCLEO-IHM07M1 Hall/Encoder sensor circuit
R27 R28
10k 10k
R30
1k8 R31
1k8
R32
1k8
C19 C20
100n
5V
expansion board provides two hardware solutions for motor position measuring: one
Section 2.2.1 Hall/Encoder motor speed
Figure 9. X-NUCLEO-IHM07M1 – BEMF detection circuit
BEMF DETECTION - SIX STEP
3V3
GPIO_BEMF
GPIO_BEMF
D6
BAT30KFILM
BAT30KFILM
R36
2.2k
BEMF1 OUT2
BEMF1
Table 1. Jumper
3V3
JP3
JUMPER
R29
10k
R33 R34 R35
C21 C22
4K7 N.M. 4K7 N.M. 4K7 N.M.
sensor) and the other based on sensorless
3V3
GPIO_BEMF
GPIO_BEMF
D7 D8
BAT30KFILM
R37
2.2k
R40
BEMF2
10k
UM1943
Analog section
STM32
settings).
3V3
D2 D3 D4
3V3
GPIO_BEMF
D9 D10
BAT30KFILM
BAT30KFILM
R38
2.2k
R41
OUT3 BEMF3
BEMF3
10k
A+/H1
B+/H2
Z+/H3
GPIO_BEMF
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