mc1451a-e ETC-unknow, mc1451a-e Datasheet - Page 17

• Manufacturer Part Number: mc1451a-e
• Description: Advanced Brushless Motor Control Chipset
• Manufacturer: ETC-unknow

Theory of Operations
The above figure shows an internal block diagram for the MC1231A
motion processor.
Each servo axis inputs the actual location of the axis using incremental
encoder signals. These encoder signals are digitally filtered for
increased reliability and then passed on to a high speed up/down
counter. This counter is used to maintain a 32-bit actual axis position
register.
The chipset can be operated in two modes. Closed loop mode, which is
the normal operating mode of the chipset, performs trajectory
generation, digital servo loop closure, and sinusoidal commutation. In
this mode the motor output value is controlled by the servo filter. Open
loop mode performs commutation only. It allows the motor output value
to be controlled directly by the host processor.
For either operating mode the desired motor output value is then
combined with the current commutation value from an internal
sinusoidal lookup. The commutation angle is determined using the
Index
Index capture
register (2)
1/a
Control
Home
Incremental Encoder
5
1/a
Host I/O controller
I/O Chip
Data
8
B
Quadrature
counter (2)
1/a
decoder
host interrupt
1
A
Internal Block Diagram
1/a
CP Chip
register (2)
Position
17
PWM mag.
DAC, PWM signal generator (6 channels)
Host command
motor encoder. Two or more commutated signals are generated for
each axis, with each signal being shifted either 90 or 120 degrees from
one another, depending on the motor type.
The resultant commutated signals are then output to the amplifier either
as PWM or DAC signals.
To perform continuous digital servoing, the trajectory and servo
calculations are performed at every sample time for all enabled axes.
The commutation is performed 4 times for each sample time.
The following table summarizes the operational parameters of the
MC1231A-series chipsets.
1/phase
System Registers (2)
Motor Output
Generator (2)
Commutation
Digital Servo
filtering (2)
DAC address
2
PosLimit
1/a
NegLimit
Trajectory profile
DAC data
generator (2)
1/a
16