CUI AMT203_1012

date
12/2010
page 1 of 6
PART NUMBER: AMT203
THE AMT203 is a high performance
absolute encoder based on capacitive
sensing technology. The AMT203
utilizes a custom ASIC to create
absolute position over a single
turn. This encoder is12 bit and
communicates via an SPI serial bus
for working as a slave to an external
microprocessor. Incremental A,B
signals with a single index pulse
per 360 deg are provided for higher
speed operation.
DESCRIPTION:
12 BIT ABSOLUTE ENCODER
FEATURES
-
12 bit (4096 positions)
SPI communication
Small Size 37mm
Incremental Line count up to 1024
Single pulse index
Capacitive ASIC technology
Modular locking hub design
for ease of installation
- SPI adjustable settings
- ‘One Touch’ zero position
ELECTRONIC SPECIFICATIONS
parameter
conditions/description
power supply
min
nom
max
units
4.5
5
5.5
V
8
10
mA
current consumption
output resolution
quadrature resolution
4,096
incr.
96, 192, 200, 250, 400, 500, 512, 1024
incremental output signals
Quadrature A, B signals and Index Z
incremental output waveform
square wave
incremental outputs
output voltage - sourcing to +5 V @ -32 mA
output voltage - sinking to ground @ -32 mA
SPI output
natural binary
SPI bus
PIC 16F690 (see datasheet)
3.8
0.55
SPI resolution
accuracy
V
V
12
bit
2
incr.
MECHANICAL SPECIFICATIONS
parameter
conditions/description
min
nom
SPI speed
mounting options
max
units
8,000
RPM
max
units
A) 2 each M1.6 on 16 mm (0.63”) bolt circle
B) 2 each #4 on 19.05 mm (0.75”) bolt circle
C) 2 each M1.6 or M2 on 20 mm (0.787”) bolt circle
D) 3 each M1.6 or M2 on 20.9 mm (0.823”) bolt
circle with washers in option B holes
E) 3 each M1.6 or M2 on 22 mm (0.866”) bolt circle
F) 4 each M1.6 or M2 on 25.4 mm (1”) bolt circle
ENVIRONMENTAL SPECIFICATIONS
parameter
conditions/description
min
operating temperature
-40
humidity
vibration
1.5mm, 3 directions, 2 hours
20050 SW 112th Ave. Tualatin, Oregon 97062
10
phone 503.612.2300
nom
125
°C
85
%RH
55
Hz
fax 503.612.2380 www.cui.com
date
12/2010
page 2 of 6
PART NUMBER: AMT203
12 BIT ABSOLUTE ENCODER
DESCRIPTION:
AMT203-V KIT
In order to provide maximum flexibility for our customers, the AMT203 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
8mm
1/4 inch
(6.35mm)
6mm
5mm
3/16 inch
(4.76mm)
4mm
1/8 inch
(3.175mm)
3mm
2mm
Blue
Snow
Red1
Green1
Yellow1
Gray60
Purple1
Orange
Light Sky Blue
TOOL A
BASE
TOOL C
TOP COVER
SHAFT
ADAPTER
CUSTOM CONFIG KEY
The AMT203 is designed for 12 bit binary (4.096) operation. For customers who may use the optional quadrature output, one of the
resolutions below may be selected as the default quadrature output.
AMT203 - XXXX - XXXX
Resolution (ppr):
0096
0192
0200
0250
0400
0500
0512
1024
20050 SW 112th Ave. Tualatin, Oregon 97062
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
phone 503.612.2300
fax 503.612.2380 www.cui.com
date
12/2010
page 3 of 6
PART NUMBER: AMT203
DESCRIPTION:
12 BIT ABSOLUTE ENCODER
ENCODER INTERFACE
PINOUT CONNECTOR 1
FUNCTION
#
14
13
12
11
10
9
8
7
6
5
4
3
2
1
SPI
T_Bit
N/A
X
N/A
A
N/A
B
B
MOSI
5 V+
SCK
GND
MISO
CSB
N/A
7
5
3
1
14 12 10 8
6
4
2
13 11 9
DETAIL B
SCALE 4 : 1
Demo Board Side
Encoder Side
1' 0.25"
(304.8)
Samtec
ISDF-07-D
Demo Board Cable
28 AWG
10 conductor
1.27 mm pitch
(Cable available without Demo Board Connector)
20050 SW 112th Ave. Tualatin, Oregon 97062
phone 503.612.2300
fax 503.612.2380 www.cui.com
date
12/2010
page 4 of 6
PART NUMBER: AMT203
12 BIT ABSOLUTE ENCODER
DESCRIPTION:
10.34 0.407
R15.49 0.610
15.30 0.602
15.33 0.604
37.39 1.472
28.58 1.125
10.93 0.430
A (3 PLCS)
22.00 0.866
2.00 0.079
(4 PLCS)
21.45 0.844
R2.10 0.083
12.60 0.496
19.05 0.750
2.95 0.116
(2 PLCS)
TOLERANCE:
±0.05mm UNLESS OTHERWISE
SPECIFIED
1.70 0.067
(2 PLCS)
0.55
RoHS
20.90 0.823
DETAIL A
SCALE 4 : 1
25.48 1.003
16.00 0.630
5.30mm
18.60mm
AMT203 ABS
US Patent No. 6892590
SCALE 5:1
20050 SW 112th Ave. Tualatin, Oregon 97062
phone 503.612.2300
R1.20mm
fax 503.612.2380 www.cui.com
date
12/2010
page 5 of 6
PART NUMBER: AMT203
DESCRIPTION:
12 BIT ABSOLUTE ENCODER
APPLICATION NOTES
Encoder operational mode
• Initialization mode: At power up the encoder goes through an initiation and stabilization procedure.
This includes microprocessor stabilization and the program for combining Coarse
and Fine channel of the encoder for getting the absolute start position. This takes
less than 0.1 seconds.
• Tracking mode: Only the Fine channel is active and the MCU internal position register is updated with
data from Fine:
– MCU 12 bit position register is updated from Fine every 48 μs.
– For accurate position update without above time delay, outputs for incremental A quad B or Count
and Up/Dwn from the Fine channel are provided. These outputs are operational up to 8000 RPM
and there is no speed error. There is an acceleration error dependent on an internal filter constant
of about 100 μs.
– When using the incremental output there also is an Index output available, with one index pulse
per turn.
Serial Peripheral Interface Commands
The SPI or Serial Peripheral Interface Bus is a standard interface promoted by Motorola and Microchip among
others. It consists of 4 signals:
MOSI: Master Out Slave In
MISO: Master In Slave Out
SCK: Serial Clock
CSB: Chip Select (active low)
SPI BUS
The SPI bus runs full duplex and transfers multiples of 8 bits in a frame. The SPI type is the most common
(CPOL=0, CPHA=0), also known as Microwire. Data is captured on the rising edge of SCK and the output data is
changed after the falling edge of SCK.
MISO
LSB
MSB
Terminology
SCK
MOSI
CSB
LSB
MSB
MSB = most significant byte
LSB = least significant byte
msb = most significant bit
lsb = least significant bit
Setup
Serial Peripheral Interface Bus (SPI) on AMT203
Figure 7: SPI BUS Timing Diagram
The msb data out on MISO is valid soon after CSB goes low. The MOSI data is valid soon after the falling edge of
SCK. The Encoder drives data out on MISO as long as CSB is low.
Normally, CSB goes low, then after 8 clocks the command is interpreted. CSB high resets the
clock counter, and terminates any command sequence.
20050 SW 112th Ave. Tualatin, Oregon 97062
phone 503.612.2300
fax 503.612.2380 www.cui.com
date
12/2010
page 6 of 6
PART NUMBER: AMT203
DESCRIPTION:
12 BIT ABSOLUTE ENCODER
SPI Commands:
The commands are all 8 bits long, the msb is shifted in first, and is the leftmost bit shown in Figure 7.
Encoder Protocol Considerations:
The Encoder is designed to operate with a high speed SPI link, in full duplex mode. This implies the host can issue commands and read data as quickly as necessary but there has to be an acknowledgement from the slave just
before the data is transferred.
Essentially the host issues a command, receives zero or more wait sequences (0xA5 or 1010,0101) then the echo
of the command followed by an optional payload.
So, for example to read the position, the host issues rd_pos (0x10 or 0001,0000), receiving a series of wait
sequences (0xA5) then a reflected rd_pos (0x10), then the MSB data followed by the LSB data.
It is recommended that the host leave a 20 us gap between reads to avoid extending the read time by forcing wait
sequences.
Command 0x00: nop_a5
This command is ignored by the Encoder and simply causes the next data to be read. The encoder responds with
0xA5 if there is nothing else to send.
Command 0x10: rd_pos
This command causes a read of the current position.
The sequence is as follows:
1) issue read command, receive idle character
2) issue NOP, receive idle character 0xA5 or 0x10
3) repeat step 2 if it is 0xA5
4) issue NOP and receive MSB position (4 bits valid data)
5) issue NOP and receive LSB position (8 bits valid data)
Note that it is possible to overlap commands, so instead of NOP is several steps above
the user could start another operation. The read and write FIFOs for the PCI streams are
16 bytes long and it is up to the user to avoid overflow.
Command 0x70: set_zero_point
This command sets the current position to zero and saves this setting in the EEPROM. The host should
send nop_a5 repeatedly after sending this command, the response will be 0xa5 while update is
proceeding and 0x80 is the response when update is finished.
20050 SW 112th Ave. Tualatin, Oregon 97062
phone 503.612.2300
fax 503.612.2380 www.cui.com