Allegro A89301 User manual

User Manual
A89301 Application Note
UM-A89301 February 27, 2019
Summary
This application note provides step-by-step instructions on how to use the A89301 Evaluation Board to program the Allegro
A89301 motor controller IC. In addition, this document contains feature descriptions and detailed circuit descriptions that are
not shown in the datasheet.
Table of Contents
Summary ............................................................................ 1
Step-by-Step Instructions ...................................................... 2
Step 1: Evaluation Board Connections................................. 2
Step 2: Launch the GUI ..................................................... 3
Step 3: Load saved parameters, if previously saved .............. 5
Step 4: Configure the basic parameters ............................... 6
Step 5: Start the motor....................................................... 7
Step 6: If motor does not move at all ................................... 8
Step 7: If motor shakes a little and stops.............................. 9
Step 8: If motor spins more than 5 cycles and stops ............ 10
Step 9: While the motor is spinning, go to the Status page;
click ‘Read Status’..........................................................11
Step 10: Adjust the motor inductance ................................ 12
Step 11: Fine tune the general parameters......................... 16
Step 12: PID Parameters ................................................. 17
Step 13: Startup Mode and Startup Settings....................... 18
Step 14: Lock detect parameters....................................... 20
Step 15: Speed control mode ........................................... 21
Step 16: Other settings .................................................... 22
Step 17: MOSFET CISS settings (CISS tab)....................... 25
Step 18: Save the settings and write into the EEPROM ....... 26
Default values of Allegro-only bits ..................................... 27
Note 1. How to determine the number of poles ................... 28
Note 2. Testing the IPD performance ................................. 29
Note 3. Debugging the lock detect feature.......................... 31
Note 4. Testing Motor Startup ........................................... 33
Other Operating Features of A89301 .................................... 34
Motor Operation Status Readback .................................... 34
I2C Hardware Connection ................................................ 35
OCL and OCP ................................................................ 35
OCP Masking Time and Filtering Time ............................... 35
Bus Current vs. Q-Axis Current......................................... 36
Gate Driver .................................................................... 36
Current Limit Level Ramping Up With Speed...................... 36
Charge Pump Capacitor Selection .................................... 37

2
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STEP-BY-STEP INSTRUCTIONS
Step 1: Evaluation Board Connections.
B. Connect
power cables to
VBBIN and GND
A. Connect USB
cable to computer
C. Set the switch
to U1 PROG E. *Do NOT
connect motor
phases
SA,SB,SC yet
* The default sengs in the A89301 may
not be appropriate, which could cause
damage to the IC or motor. Sengs should
be veried before connecng a motor.
F. Turn on power
(to rated voltage)
D. Set JMP2 to
upper posion

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Step 2: Launch the GUI.

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Step 2: Launch the GUI. (continued)
B. If you see this error message,
install the USB to I2C chip driver
(FTDI D2XX). Check USB cable
connecon.
C. Make sure the power supply is
ON, and the switch is set to ‘U1
PROG’.
D. Try talking to the IC again. (As I2C_SDA
is shared with funconal mode FG pin, it
is possible the rst aempt failed because
the FG is pulled low).
To guarantee this won’t happen again in
the future, disable the FG funcon:

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Step 3: Load saved parameters, if previously saved.
Device parameters can be saved to a file. If a file for this (or similar) application has been created, open that file. Verify the Allegro-
only bits in the file are their default values.
B.
C.
E. F.
A.
D.

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Step 4: Configure the basic parameters.
Note: These numbers do not need to be very accurate; use the best estimation. There is fine tuning later in the process.
The number of pole pairs. For example,
12 pole motor: input 6 pole pairs.
See NOTE 1 to determine the number of poles.
The supply voltage that motor will be
working at. For example:
•Computer fan, 12 V power supply:
input 12 V.
•Supply voltage speed control, range
8 V to 24 V: input 24 V.
•Lithium baery system, voltage
11.1 V to 12.6 V: input 12 V.
Expected motor speed at ‘Rated Voltage’,
normal load condion, and 100% control
demand.
For example, pedestal fan, 1300 rpm with
blades and 1450 rpm without blades:
input approximately 1300 rpm.
Motor operaon current under ‘Rated
Voltage’, with normal load condion.
Rated Voltage, Rated Speed, and Rated
Current must be consistent.
Motor phase to center tap resistance,
measure phase to phase R and divide by
two.*
*Be sure to use an accurate mmeter. A ber oon may be to
apply a current through the motor, measure voltage across it, and
calculate resistance.
In the “Advanced” page, there is a
parameter defining the current sensing
resistor value. Program this value
appropriately.

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Step 5: Start the motor.
A. Connect motor phase A, B, and C.
B. Keep ‘Set speed demand via I2C’ checked.
C. Select the speed demand to 50%, and click Toggle Run/Stop.
The motor should start spinning.
If it does, go to step 9.
If not:
Doesn’t move at all,
go to step 6.
Shook a li�le bit
then stopped, go
to step 7.
Spun more than 5
cycles and stopped,
go to step 8.

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Step 6: If motor does not move at all:
A. Look at the LED indicator
connected to the Fault pin,
and follow the fault table to
determine the root cause.
B. If the LED is o, connect a current probe and
voltage probe to the motor outputs and check
if there is any current / voltage output to the
motor phase. If there is voltage but no current,
check motor phase connecons.
C. If the fault indicator LED is showing the “zero speed demand”, double
check the I2C speed demand seng is correct.
D. Toggle Run/Stop to retry startup.

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Step 7: If motor shakes a little and stops:
B. If it is OCP, check the phase output
wire connecons.
C. Otherwise, it is likely lock
detecon. If so, lower/slow down
the acceleraon seng. Note there
are two acceleraon ranges.
D. Toggle Run/Stop to retry the startup.
A. Look at the LED indicator
connected to the Fault pin,
and follow the fault table to
determine the root cause.

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Step 8: If motor spins more than 5 cycles and stops:
B. The problem is likely lock detec�on. If so,
go to the Standby / Protec�on page and
disable all the lock detect features.
C. Toggle Run/Stop to retry the startup.
A. Look at the LED indicator
connected to the Fault pin,
and follow the fault table to
determine the root cause.
D. One by one, enable each lock detect
feature to determine which is the cause of
the fault and which can be re-enabled.

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Step 9: While the motor is spinning, go to the Status page; click ‘Read Status’.
A. While the motor is spinning, go to the Status page. Click ‘Read Status’.
B. The system diagnos�cs
func�on will show you IC
temperature, motor
speed, supply current,
phase current, and supply
voltage. Compare the
supply current and voltage
data with the result
showing on the power
supply.
C. The Control demand is the amplitude that is
commanded (it should match the I2C speed demand
value). The Amplitude command is the actual
amplitude provided to the motor phase. If the
command is less than the demand, it is because of the
current limit. This problem is solved in Step 11.

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Step 10: Adjust the motor inductance.
A. Motor inductance is difficult to measure—it
varies with opera�on frequency, phase
current (satura�on), and also with the rotor
posi�on. Thus, A89301 provides an easy
method to adjust the inductance value and
achieve the best efficiency.
B. While the motor is spinning, connect a current probe to phase A, and connect a
voltage probe to phase A.
C. Enable the open window which is a debug
func�on. Remember to disable the
window before finalizing the parameters.

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Step 10: Adjust the motor inductance. (continued)
D. There will be a small window opened
on phase A (winding current is flat at
0A). Observe phase A voltage inside
the window:
•If voltage > VBB/2, increase L.
•If voltage < VBB/2, decrease L.
•If voltage = VBB/2, best efficiency.

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Step 10: Adjust the motor inductance. (continued)
E. It may not be possible t an inuctance value that makes the phase A
voltage exactly VBB/2. If not, choose the closest seng.
F. Theorecally, jusng the inuctance value at one speell ork for all other
spees. Hever, it is recommeneto verify at another spee. If it esn’t
ork at other speeit is recommeneto make the justment at ratespee.
G. For motors running at high spe500 Hz), opening the iomay cause a
big storon in the phase current, ich can trigger the lock etecon. In this
case, capture the rst inoaveform, stop the oscilloscope, anthen make
the justment.
H. For motors ith very loinuctance, if
the phase current looks like this, set
the inuctance value to level 0 or 1,
anthen start the justment.
I. The Direct ive angle feature bypasses
automac phase angle justment. If
enable, uctor seng slier is
useto set the xeavance angle, in
units of grees.

15
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Step 10: Adjust the motor inductance. (continued)
J. There is another way to double-conrm the inductance is opmized.
•Control the motor to xed high speed (around 80% of rated speed).
•Read phase current RMS from scope.
•Change the inductance seng around the value from the previous step.
•List the RMS current for each inductance seng and choose the one with
smallest RMS current.
•For example, look at the table, inductance seng 2 will cause the minimum
current axed speed (3000 rpm). Therefore, choose seng 2.
inductance se�ng phase RMS current motor speed
0 2.35 A 3000 rpm
1 2.25 A 3000 rpm
22.21 A 3000 rpm
3 2.28 A 3000 rpm
4 2.39 A 3000 rpm

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Step 11: Fine tune the general parameters.
A. Increase the speed demand to 100%, and
read the status.
B. The bus current value should match the
actual bus current shown on the power
supply or a mul�-meter. If not, adjust the
sense resistor value slightly (on the
advanced page).
C. The ‘Control demand’ and ‘Amplitude
command’ should be both 100% (511).
D. If the ‘Amplitude command’ is less than 511, go to the general parameter
page and increase the ‘Rated current’ value. The motor speed should
increase while the ‘Rated current’ value is increased.
E. When the ‘Control demand’ and ‘Amplitude command’ are both 511,
record the ‘Motor speed’ from the status page. Enter this value as the
‘Rated speed’ parameter.
F. Record the ‘Bus current’ from the status page. Enter this value as the
‘Rated current’ parameter.

17
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A. Restart the motor.
B. If the PID parameter is too high or too low, opera�on will fail. Connect a
current probe and voltage probe for the debugging.
•If current shows low frequency oscilla�on,
the PID parameter is too low.
•If current shows distor�on within in one
electrical cycle, the PID parameter is too
high.
Step 12: PID Parameters.

18
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Step 13: Startup Mode and Startup Settings.
A. If this is an air purifier type of applica�on
which doesn’t requirezero reverse
rota�on startup, and startup �me is not
cri�cal, select ‘Align & go’.
B. If this is a ceiling fan or polefan applica�on which strictly requires no reverse
rota�on at startup, select ‘2 pulseIPD’.
•The ‘IPD current threshold’ must beset high enough so that startup is
reliable, and as low as possibleto minimizethe acous�c noiseduring IPD.
C. For somemotors, dueto manufacturing tolerance (inductance error between
phase to phase), the 2 pulse IPD won’t be able to detect the ini�al posi�on
reliably. In that case, select ‘6 pulseIPD’.
D. If this is a seat cooling fan or pump wherefaster startup is desirable and slight
reverseoscilla�on at startup is acceptable, select ‘Slight move’.
•Adjust the ‘Slight move amplitudedemand’, and choose the best startup
performance. Too high a valuewill causeseverestartup oscilla�on, and
too low a valuewill cause startup failure.
E. NOTE 2 explains how to use the GUI’s IPD page to test the performance.
F. Compare these three op�ons in the applica�on and choosethe best fit.

19
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Step 13: Startup Mode and Startup Settings. (continued)
G. A89301 provides 7 opons for the
startup current. The motor phase
current will gradually increase from the
programmed value.
H. Reducing the startup current may cause startup to fail in open-loop mode,
even if startup was veri successful before the change. In this case, reduce
the acceleraon accordingly.
I. If faster startup is required, increase the
acceleraon value. Startup current may
need to be increased accordingly.
If ‘Max start current’ is enabled, the
control demand is ignored, and 100%
control demand is always used. The current will
be limited by the startup current seng.
K. Increasing the rst cycle speed will
make the startup faster.
L. Perform a comprehensive test to ensure startup reliability.
1) Dierent inial posion.
2) Dierent inial speed.
3) Dierent supply voltage.
4) Dierent operaon temperature.
J. Note the startup current and acceleraon only aects the reliability and
startup me. If the motor fails aer at least 5 cycles, then changing the startup
parameters won’t help.
The GUI provides the startup test tool of reliability test. Refer to Note 4.

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Step 14: Lock detect parameters.
Note: If there is any issue with lock detect, refer to NOTE 3 for further debugging.
Detect the lock during startup. If it is
disabled, a locked motor condion can
sll be detecon aer startup stage, it
just takes longer.
A89301 aempts to start the motor again aer 5s or 10s
waing. But it will only aempt so many mes, then stop
aempng un power cycle, or restart the motor
demand (speed demand).
Lock detect waing me.
Enabled, the IC will report a failure if the
motor “speed” is abnormally fast.
For ceiling fan, with exible shaconnecon, there
is a lock condion when the shaand motor keep
vibrang and cause ‘papapa’ noise.
In the normal operaon, the motor generates
BEMF. The algorithm observes the BEMF by
calculang the current and voltage, and reports
abnormal BEMF. Select Robust will get rid of the
mis-trigger but it takes longer to detect.
Disabled, lock detect begins once the motor reaches
6% of rated speed. Enabled, it becomes 12%.