AN1913D Freescale Semiconductor / Motorola, AN1913D Datasheet - Page 21

• 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

Figure 5-7. Flow Chart - BLDC Commutation with Back-EMF Zero Crossing Sensing
The flow chart explaining the principle of BLDC Commutation control with Back-EMF Zero Crossing
Sensing is shown in
No
Wait for Per_Toff until phase
detected between previous
Service of Commutation:
current decays to zero
BEMF Zero Crossing
BEMF Zero Crossing
BEMF Zero Crossing
Preset commutation
Commutation Done
has commutation
commutations?
time expired?
Yes
Detected?
Figure
missed?
BLDC control with BEMF Zero Crossing using ADC
Freescale Semiconductor, Inc.
For More Information On This Product,
No
5-7.
No
Yes
Go to: www.freescale.com
Make motor Commutation
Yes
Yes
No
Service of received BEMF
Zero Crossing:
corrected setting of
commutation time
Yes
Corrective Calculation 1.
BEMF Zero Crossing missed
Corrective Calculation 2.
corrected setting of
commutation time
has commutation
time expired?
Control Technique
No
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