AN1913D Freescale Semiconductor / Motorola, AN1913D Datasheet - Page 13

• Manufacturer Part Number: AN1913D
• Description: 3-phase BLDC Motor Control with Sensorless Back-EMF ADC Zero Crossing Detection using DSP 56F80x
• Manufacturer: Freescale Semiconductor / Motorola

PC Master
The resistor network is used to divide sensed voltages down to a 0-3.3V voltage level. Zero Crossing
detection is synchronized with the center of center aligned PWM signal by the software in order to
filter high voltage spikes produced by the switching of the IGBTs (MOSFETs).
START
DOWN
STOP
UP
Power line
3 Phase Voltages
DC-Bus Voltage/Current
Temperature
SCI
Required
Speed
BLDC control with BEMF Zero Crossing using ADC
Freescale Semiconductor, Inc.
3 phase BLDC
Power Stage
For More Information On This Product,
Zero
Crossing
Zero Crossing
Period, Position
Recognition
DC Bus Current &
3 phase Voltages,
DC Bus Voltage
Figure 4-1. System Concept
Sensing
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ADC
1/T
Commutation
Period
Actual Speed
Zero Crossing
Time moment
Regulator
Speed PI
Commutation
Control
Three-Phase
Inverter
Dead Time
Generator
PWM
with
System Design Concept
DSP56F80x
Duty
Cycle
PWM
BLDC
Motor
3-ph
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