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SERIES: AMT31 | DESCRIPTION: MODULAR COMMUTATION ENCODER
FEATURES
• patented capacitive ASIC technology
• low power consumption
• U, V, W commutation phase channels
• 2, 4, 6, 8, 10, 12, 20 motor poles w/ incremental resolutions up to 4096 PPR
• resolutions and poles programmable with AMT Viewpoint™ PC software
• differential line driver versions
• digitally set zero position with AMT One Touch Zero™ module or serial commands
• compact modular package with locking hub for ease of installation
• radial and axial cable connections
• -40~125°C operating temperature
ELECTRICAL
parameter
conditions/description
min
power supply
VDD
4.5
start-up time1
current consumption
with unloaded output
VDD-0.1
single ended channels
output high level
output low level
output current (per channel)
rise/fall time
output high level
output low level
output current (per channel)
rise/fall time
3
differential RS-422 channels
Note:
typ
max
5
5.5
units
V
200
ms
16
mA
8
0.1
15
7
11
0.1
20
20
min
typ
max
V
V
mA
ns
V
V
mA
ns
units
1. Encoder must be stationary during start-up.
INCREMENTAL CHARACTERISTICS
parameter
conditions/description
waveform
CMOS voltage square wave
phase difference
A leads B for CCW rotation (viewed from front)
quadrature resolutions2
48, 96, 100, 125, 192, 200, 250, 256, 360, 384, 400, 500,
512, 768, 800, 1000, 1024, 1600, 2000, 2048, 2500, 4096
index3
one pulse per 360 degree rotation
90
PPR
accuracy
0.2
quadrature duty cycle (at each
resolution)
Notes:
degrees
48, 96, 100, 125, 192, 256, 384
200, 250, 360, 400, 768, 800
500, 1000, 1600
512, 1024 , 2048, 4096
2000
2500
49
48
46
50
44
43
50
50
50
50
50
50
degrees
51
52
54
50
56
57
2. Resolutions programmed with AMT Viewpoint™ PC software. Default resolution set to 2048 PPR. Listed as pre-quadrature, meaning final number of counts is PPR x 4.
3. Zero position alignment set with AMT One Touch Zero™ module, AMT Viewpoint™ PC software, or serial commands.
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%
%
%
%
%
%
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CUI DEVICES | SERIES: AMT31 | DESCRIPTION: MODULAR COMMUTATION ENCODER
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COMMUTATION CHARACTERISTICS
parameter
conditions/description
channels
CMOS Voltage (S)
Quadrature Line Driver (Q)
Commutation Line Driver (C)
Line Driver (D)
motor poles4
2, 4, 6, 8, 10, 12, 20
waveform4
CMOS voltage square wave
phase difference
WYE motor winding configurations
Notes:
min
typ
max
units
A, B, Z, U, V, W
¯ B, B,
¯ Z, ¯
A, A,
Z, U, V, W
¯
A, B, Z, U, ¯
U, V, ¯
V, W, W
¯ B, ¯
¯ V, ¯
¯
A, A,
B, Z, ¯
Z, U, U,
V, W, W
electrical
degrees
120
4. Pole counts and waveform direction set via AMT Viewpoint™ PC software. Default poles set to 4 poles and counter-clockwise direction.
MECHANICAL
parameter
conditions/description
min
motor shaft length
motor shaft tolerance
weight
typ
weight varies by configuration
units
mm
NOM +0/-0.015
mm
15.7
g
axial play
rotational speed (at each
resolution)
max
9
±0.3
mm
48, 96, 100, 125, 192, 200, 250, 256, 384, 400, 500, 512,
800, 1000, 1024, 2048
8000
RPM
360, 768, 1600, 2000, 4096
4000
RPM
2500
2500
RPM
max
units
125
°C
ENVIRONMENTAL
parameter
conditions/description
min
operating temperature
typ
-40
humidity
non-condensing
vibration
10~500 Hz, 5 minute sweep, 2 hours on each XYZ
shock
3 pulses, 6 ms, 3 on each XYZ
RoHS
yes
85
%
5
G
200
G
max
units
SERIAL INTERFACE
parameter
conditions/description
min
protocol
serial UART
controller
driven by onboard Microchip PIC18F25K80. See Microchip documentation for additional details.
data rate
8 data bits, no parity, 1 stop bit, least significant bit first
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typ
115200
baud
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CUI DEVICES | SERIES: AMT31 | DESCRIPTION: MODULAR COMMUTATION ENCODER
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WAVEFORMS
Figure 1
Quadrature signals with index showing
counter-clockwise rotation
I
Z
A
T
B
S
P
S
S
S
The following parameters are defined by the resolution selected for each encoder. The
encoders resolution is listed as Pulses Per Revolution (PPR), which is the number of
periods (or high pulses) over the encoders revolution.
Parameter
Expression
Units
Notes
Pulses Per Revolution
This is the user selected value and the format
all resolutions are listed in
This is the number of quadrature counts the
encoder has
PPR
resolution
CPR
counts
PPR x 4
Counts Per Revolution
T
period
360/R
mechanical degrees
P
pulse width
T/2
mechanical degrees
S
A/B state width
T/4
mechanical degrees
This is the width of a quadrature state
mechanical degrees
The width of a once per turn index is the state
width for A & B lines
I
Note:
Description
index width
T/4
For more information regarding PPR, CPR, or LPR (Lines Per Revolution) view https://www.cuidevices.com/blog/what-is-encoder-ppr-cpr-and-lpr
Figure 2
Commutation signals with index (The programmable
direction setting dictates in which direction of rotation U
will lead V, and V will lead W)
Z
U
I
S
S
S
S
S
S
V
P
C
W
T
The following parameters are defined by the resolution and pole count selected for
each encoder, where PPR = resolution and M = motor poles.
Parameter
Description
Expression
Units
T
period
360/M
mechanical degrees
P
pulse width
T/2
mechanical degrees
I
index width
360/(PPR*4)
mechanical degrees
U/V/W state
width
60
electrical degrees
S
C
phase
spacing
T/6
mechanical degrees
120
electrical degrees
T/3
mechanical degrees
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CUI DEVICES | SERIES: AMT31 | DESCRIPTION: MODULAR COMMUTATION ENCODER
date 08/05/2022 | page 4 of 11
PART NUMBER KEY
For customers that prefer a specific AMT31 configuration, please reference the custom configuration key below.
AMT31XX - XXXX - XXXX - XX - XX - X
Mounting Base:
S = Standard
W= Wide
Base Number
Orientation:
2 = Radial
3 = Axial
Quadrature
Resolution (PPR):
0500
0048
0512
0096
0768
0100
0800
0125
1000
0192
1024
0200
1600
0250
2000
0256
2048
0360
2500
0384
4096
0400
Output Signals:
S = CMOS Voltage
Q = Quadrature Line Driver
C* = Commutation Line Driver
D* = Line Driver
*Radial orientation only.
Direction:
“blank” = CCW
CW = clockwise
Motor Poles:
02 10
04 12
06 20
08
Sleeve Bore Diameter:
2000 = 2 mm
3000 = 3 mm
3175 = 3.175 mm (1/8”)
4000 = 4 mm
4760 = 4.76 mm (3/16”)
5000 = 5 mm
6000 = 6 mm
6350 = 6.35 mm (1/4”)
8000 = 8 mm
AMT31-V KITS
In order to provide maximum flexibility for our customers, the AMT31 series is provided in kit form standard. This allows the user to implement the encoder into a range of
applications using one sku#, reducing engineering and inventory costs.
SLEEVES
ORDERING GUIDE
AMT31XX-V
Orientation:
2 = Radial
3 = Axial
Output Signals:
S = CMOS Voltage
Q = Quadrature Line Driver
C* = Commutation Line
Driver
D* = Line Driver
2mm
3mm
1/8 inch
(3.175mm)
4mm
3/16 inch
(4.76mm)
5mm
6mm
1/4 inch
(6.35mm)
8mm
Light Sky
Blue
Orange
Purple
Gray
Yellow
Green
Red
Snow
Blue
BASE
WIDE
BASE
*Radial orientation only.
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TOP
COVER
SHAFT
ADAPTER
TOOL A
TOOL C
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CUI DEVICES | SERIES: AMT31 | DESCRIPTION: MODULAR COMMUTATION ENCODER
date 08/05/2022 | page 5 of 11
ENCODER INTERFACE
PINOUT CONNECTOR
Function
#
AMT312S
AMT312Q
AMT312C
AMT312D
AMT313S
AMT313Q
1
TX_ENC+
TX_ENC+
TX_ENC+
TX_ENC+
RX_ENC+
RX_ENC+
2
RX_ENC+
RX_ENC+
RX_ENC+
RX_ENC+
TX_ENC+
TX_ENC+
3
U+
U+
U+
U+
U+
U+
4
GND
GND
GND
GND
GND
GND1
5
W+
W+
W+
W+
W+
W+
6
+5 V
+5 V
+5 V
+5 V
+5 V
+5 V
7
V+
V+
V+
V+
V+
V+
8
B+
B+
B+
B+
B+
B+
9
N/A
B-
N/A
B-
N/A
B-
10
A+
A+
A+
A+
A+
A+
11
N/A
A-
N/A
A-
N/A
A-
12
Z+
Z+
Z+
Z+
Z+
Z+
1
1
1
1
1
13
N/A
Z-
N/A
Z-
N/A
Z-
14
MCLRB
MCLRB
MCLRB
MCLRB
MCLRB
MCLRB
15
N/A
N/A
W-
W-
N/A
N/A
16
N/A
N/A
V-
V-
N/A
N/A
17
N/A
N/A
U-
U-
N/A
N/A
Note:
1. Connect encoder GND to motor chassis as closely as possible. For additional grounding techniques contact CUI Application Support.
AMT312S, AMT312Q,
AMT312C & AMT312D
AMT313S & AMT313Q
A
A
B
17 15 13 11 9
16 14 12 10 8
7
5
6
3
4
13 11 9
1
2
7
5
3
1
14 12 10 8
6
4
2
SECTION A-A
DETAIL B
SCALE 4 : 1
SCALE 4 : 1
Mating Connector:
JAE FI-W17S
Mating Connector:
Samtec ISDF-07-D-L
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CUI DEVICES | SERIES: AMT31 | DESCRIPTION: MODULAR COMMUTATION ENCODER
date 08/05/2022 | page 6 of 11
MECHANICAL DRAWING
AMT312S, AMT312Q, AMT312C & AMT312D
units: mm
tolerance: ±0.1
10.34 0.407
R15.49 0.610
15.30 0.602
15.33 0.604
37.25 1.467
28.58 1.125
10.34 0.407
AMT313S & AMT313Q
units: mm
tolerance: ±0.1
10.34 0.407
R15.49 0.610
15.30 0.602
15.33 0.604
37.39 1.472
10.93 0.430
28.58 1.125
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CUI DEVICES | SERIES: AMT31 | DESCRIPTION: MODULAR COMMUTATION ENCODER
date 08/05/2022 | page 7 of 11
MECHANICAL DRAWING (CONTINUED)
MOUNTING HOLE PATTERNS
STANDARD BASE
units: mm[inch]
tolerance: ±0.1
22.00 0.866
21.55 0.848
20.90 0.823
12.60[0.496]
R1.05 0.041
DETAIL A
SCALE 4 : 1
2.00 0.079
(4 PLCS)
2.95 0.116
(2 PLCS)
16.00 0.630
0.275 0.011
A (3 PLCS)
1.70 0.067
(2 PLCS)
19.05 0.750
25.40 1.000
WIDE BASE
units: mm[inch]
tolerance: ±0.1
32.44 1.277
3.00 0.118
(2 PLCS)
2.96
2.87 X 2.96
(2 PLCS)
A
2.87
0.09
DETAIL A
SCALE 4 : 1
46.02 1.812
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CUI DEVICES | SERIES: AMT31 | DESCRIPTION: MODULAR COMMUTATION ENCODER
date 08/05/2022 | page 8 of 11
ASSEMBLY PROCEDURE
STEP 1
STEP 2
STEP 3
Align Tool C with
flange on Base
1. Insert Tool A as a spacer that defines the distance to
the mounting surface.
2. Slide appropriate sized Sleeve over shaft all the way down to Tool A.
3. Slide Shaft Adaptor over Sleeve.
4. Use Tool C to press Shaft Adaptor over Sleeve (ensure Shaft Adapter
and Tool C spline alignment) until flush with Tool A.
STEP 4
1. Remove Tools A and C.
2. Place Base on motor, with Tool C used as a centering tool.
STEP 5
1. Snap the Top Cover onto the Base, carefully observing that the
teeth of the Shaft Adaptor align with the grooves in the hub. *
1. Fasten the Base on the motor (Tool C may need to be
rotated to allow for some mounting configurations).
2. Remove Tool C.
* We recommend no more than three cycles of mounting and
removal of the AMT top cover base. Multiple cycles of mounting
and removing the top cover can cause base fatigue over time and
affect encoder performance.
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1. Align Tool C with flange on Base.
2. Slide Base and Tool C onto motor, centering onto
the Shaft Adapter.
STEP 6
1. Make sure the snaps are fully engaged by pressing
on the Hub with the reverse side of Tool C.
2. When assembly is finished, the Shaft Adaptor, Sleeve
and Rotor Hub should all be flush with the Motor
Shaft rotating freely.
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APPLICATION NOTES
SERIAL INTERFACE
The AMT31 series encoder is designed to operate with a serial UART interface. This interface allows the encoder to be configured and programmed
by the AMT Viewpoint™ application. Along with programming, the AMT Viewpoint™ application uses the serial interface for diagnostics and motor pole
alignment. Below are instructions on how to use the serial interface for position zeroing.
Table 1
Serial Commands
Command
Action
Use
0
This command sends an ascii ‘0’ (hex value
0x30).
This zeros the encoder and sets the index at the current angular position along
with the rising edge of the commutation channel U. This position is stored in nonvolatile memory and will remain present until a zero command is set again or the
encoder is reprogrammed via the AMT Viewpoint™ application.
Q
This command sends an ascii ‘Q’ (hex value
0x51).
This command restarts the encoder as if it were power cycled.
Table 2
Serial Pins
Pin
Description
Connection
TX_ENC+
This is the pin that the encoder transmits
serial data on.
Connect this pin to the receiver input of your serial/UART interface.
RX_ENC+
This is the pin that the encoder receives
serial commands on.
Connect this pin to your serial/UART interface transmitter output.
MCLRB
This pin is used to force the encoder into
reset for reprogramming via the AMT
Viewpoint™ application.
Connection of this pin is not required for the above serial commands.
The serial interface operates at 115200 baud with 8 data bits, no parity, and 1 stop bit, and 1 start bit. This is the standard UART protocol. Data lines
TX_ENC+ and RX_ENC+ are high when inactive.
Figure 3
Serial Timing Diagram
RX_ENC+
Start
0
1
2
3
4
5
6
7
Stop
Command: 0 (hex: 0x30, binary: 0b00001100)
TX_ENC+
Start
0
1
2
3
4
5
6
Response: \r (hex: 0x0d, binary: 0b10110000)
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7
Stop
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APPLICATION NOTES (CONTINUED)
COMMUTATION ALIGNMENT AND ZERO POSITION
The AMT31 series encoder requires minimal setup time for brushless DC (BLDC) motor applications. Installation can be completed with either a PC
with the AMT Viewpoint™ application installed, an AMT-OTZ-1 zero alignment module, or any 5V serial interface. The following steps explain the proper
commutation alignment procedure for the AMT31 encoder.
1.
Ensure AMT31 encoder is set for correct pole count. To verify or change settings use the AMT Viewpoint™ software.
2.
Mount encoder following AMT Assembly procedure.
3.
Use the motor manufacturer’s documentation to determine the correct motor phase to energize for alignment. Energized phase will coincide with
the rising edge of the AMT31 encoders ‘U’ signal. This typically means energizing phase 1 by applying positive voltage to the wire labeled ‘phase 1’,
and grounding the wire labeled ‘phase 2’. The third wire always remains unconnected.
4.
Using a power supply, energize the two wires found previously. This will lock the rotor into a fixed position.
5.
Connect AMT31 encoder to an AMT-OTZ-1 zero alignment module, the AMT Viewpoint™ application, or any suitable 5V serial interface.
6.
Use any of the connected devices to issue an alignment command to the encoder. This will digitally set the rising edge of ‘U’ and the ‘Z’ index to the
current angular position.
7.
Remove power from motor phase windings; connect motor and encoder to proper motor driver.
8.
If the above is done correctly your AMT31 encoder is now ready for operation. As a verification of alignment you may power the encoder, and use
an oscilloscope to monitor phase 1 of the motor and the ‘U’ channel of the encoder as you hand spin the motor. If alignment is correct, the square
wave generated on the ‘U’ channel will overlap perfectly with the sine wave generated by phase 1 of the motor. If alignment does not match, recheck
motor documentation and retry alignment procedure.
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CUI DEVICES | SERIES: AMT31 | DESCRIPTION: MODULAR COMMUTATION ENCODER
date 08/05/2022 | page 11 of 11
REVISION HISTORY
rev.
description
date
1.0
initial release
09/30/2014
1.01
updated datasheet
06/25/2015
1.02
updated datasheet
10/13/2015
1.03
added 360 & 2500 PPR resolutions, increased operating temperature to 125°C
12/18/2017
1.04
changed outer mounting holes to be oblong on wide base version
10/10/2018
1.05
brand update
11/21/2019
1.06
updated quadrature duty cycle details
10/08/2020
1.07
added motor shaft tolerance details, updated start-up details
09/10/2021
logo, datasheet style update
08/05/2022
1.08
The revision history provided is for informational purposes only and is believed to be accurate.
CUI Devices offers a one (1) year limited warranty. Complete warranty information is listed on our website.
CUI Devices reserves the right to make changes to the product at any time without notice. Information provided by CUI Devices is believed to be accurate
and reliable. However, no responsibility is assumed by CUI Devices for its use, nor for any infringements of patents or other rights of third parties which may
result from its use.
CUI Devices products are not authorized or warranted for use as critical components in equipment that requires an extremely high level of reliability. A
critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life
support device or system, or to affect its safety or effectiveness.
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