beautypg.com

Motorola M68HC08 User Manual

Page 46

background image

BLDC Motor Control

Designer Reference Manual

DRM028 — Rev 0

46

BLDC Motor Control

MOTOROLA

during several commutations, while producing the required torque. Until
the back-EMF feedback is locked, the commutation process (explained
in

Running

) assures that commutations are done in advance, so that

successive back-EMF zero crossing events are not missed.

After several successive back-EMF zero crossings:

Exact commutation time can be calculated

Commutation process is adjusted

Control flow continues to the Running state

The BLDC motor is then running with regular feedback and the speed
controller can be used to control the motor speed by changing the PWM
duty cycle value.

F

re

e

sc

a

le

S

e

m

ic

o

n

d

u

c

to

r,

I

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

n

c

.

..