mc1451a-e ETC-unknow, mc1451a-e Datasheet - Page 38

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

Commutation Command Summary:
The following table summarizes the commands that are used in
conjunction with sinusoidal commutation:
Command
SET_PHASE_3
SET_PHASE_2
SET_PHASE_HALL
SET_PHASE_ALGOR
SET_PHASE_ENC
SET_PHASE_MICRO
PRESCALE_ON
PRESCALE_OFF
SET_PHASE_CNTS
SET_PHASE_TIME
SET_PHASE
SET_PHASE_OFFSET
SET_KPHASE
SET_HALL_SENSE
INIT_PHASE
GET_PHASE_INFO
GET_PHASE_CNTS
GET_PHASE_TIME
GET_PHASE_OFFSET
GET_KPHASE
GET_HALL_SENSE
GET_HALLS
GET_PHASE
Motor Output Configuration
The MC1231A series of chipsets supports two motor output methods,
PWM and DAC (up to 16 bit resolution).
Below is shown a typical amplifier configuration for a 3-phase brushless
motor using the PWM output mode:
Function
Sets the commutation waveform for 3-
phase brushless motors.
Sets the commutation waveform for 2-
phase brushless motors.
Sets the phase initialization mode to
Hall-sensor-based
Sets the phase initialization mode to
algorithmic.
Sets commutation mode to encoder-
based
Sets commutation mode to
microstepping
Sets the encoder prescalar on
Sets the encoder prescalar off
Sets the # of encoder counts per
commutation electrical cycle.
Sets the amount of time to wait during
phase initialization
Sets the current phase angle
Sets the phase offset angle
Sets the velocity phase advance gain
Sets the logic level interpretation for the
Hall sensor inputs
Begins the algorithmic phase
initialization procedure.
Returns various commutation-related
state information set by the host
Returns the number of encoder counts
per electrical cycle
Returns the wait time used during phase
initialization
Returns the phase offset angle
Returns the phase advance gain
Returns the logic level interpretation for
the Hall sensor inputs
Returns the status of the hall sensors
Returns the current commutation angle.
38
In this configuration the chipset outputs 3 phased PWM magnitude
signals per axis. These signals are then fed directly into 3 half-bridge
type voltage amplifiers.
Below is shown a typical amplifier configuration for a 3-phase brushless
motor using the DAC output mode:
When using DAC output mode the digital word provided by the chipset
must first be converted into a voltage using an external DAC. Two DAC
channels are required per axis. To construct the third phase for a
brushless motor (C phase) the sum of the A and B signals must be
'negated' using C = -(A+B).
This is usually accomplished with an Op-amp circuit. In addition, if
current loop control is desired the three output signals are usually
arranged so that the sum of the currents flowing through the windings of
the motor are zero.
Motor Output Signal Interpretation
The following graph shows the desired output voltage waveform for a
single phase.
+ motor command
- motor command
Brushless Motor (PWM Mode) Connection Scheme
MC1231
MC1231
Brushless Motor (DAC Mode) Connection Scheme
0
DAC 1A
DAC 1B
DAC 2A
DAC 2B
Axis #2 Phase B
Axis #1 Phase B
Axis #2 phase A
Axis #2 Phase C
Axis #1 Phase C
Axis #1 phase A
C=-(A+B)
Amplifiers
C=-(A+B)
Axis #2
Axis #1
Axis #2 phase A
Axis #1 Phase C
Axis #2 Phase B
Axis #2 Phase C
Axis #1 phase A
Axis #1 Phase B
Amplifiers
Mtr #2
Mtr #1
Mtr #1
Mtr #2