AN1905 ST Microelectronics, Inc., AN1905 Datasheet - Page 61

• Manufacturer Part Number: AN1905
• Description: St7mc Three-phase BLDC Motor Control Software Library
• Manufacturer: ST Microelectronics, Inc.

Figure 44. PWM applied on low/high side on a rising Bemf during demagnetizationf
T0
T1
T1
T0
PWM OFF
PWM ON
A
A
T0-T3 with PWM applied
on high side during demagnetization
T2
T3
T2
on high side
M
I
T3
I
M
d
d
T0-T5 with PWM applied
Step 1
B
ST7MC THREE-PHASE BLDC MOTOR CONTROL SOFTWARE LIBRARY
B
I
2
HV
HV
Step 2
T4
T5
T4
T5
C
C
T0
T1
T0-T3 ->T0-T5
A
Commutation
demagnetization current
I
Σ
I
d
1
HV
HV/2
T2
T3
1
: free wheeling
0V
Voltage on
B
OR
phase B
Demagnetization
HV
Σ
2
T4
T5
on low side during demagnetization
t
C
T0-T5 with PWM applied
T0
T1
T0
T1
A
A
Step 2
T2
T3
T2
T3
M
I
M
I
d
d
B
B
I
2
HV
HV
PWM OFF
PWM ON
T4
T5
T4
T5
C
C
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