Agilent AEDB-9140 Series
Three Channel Optical Incremental
Encoder Modules with Codewheel,
100 CPR to 500 CPR
Data Sheet
Description
The AEDB-9140 series are
three channel optical
incremental encoder modules
offered with a codewheel.
When used with a codewheel,
these low cost modules detect
rotary position. Each module
consists of a lensed LED
source and a detector IC
enclosed in a small plastic
package. Due to a highly
collimated light source and a
unique photodetector array,
these modules are extremely
tolerant to mounting
misalignment.
The AEDB-9140 has two
channel quadrature outputs
plus a third channel index
output. This index output is a
90 electrical degree high true
index pulse which is generated
once for each full rotation of
the codewheel.
The AEDB-9140 is designed
for use with a codewheel
which has an optical radius of
11.00 mm (0.433 inch).
Features
•
Two Channel Quadrature Output
with Index Pulse
•
Resolution from 100 CPR to 500
CPR (Counts Per Revolution)
•
Low Cost
The quadrature signals and the
index pulse are accessed
through five 0.46 mm square
pins located on 1.27 mm(pitch)
centers.
Applications
The AEDB-9140 provide
sophisticated motion control
detection at a low cost, making
them ideal for high volume
applications. Typical
applications include printers,
plotters, tape drives, and
industrial and factory
automation equipment.
Note: Agilent Technologies encoders are not
recommended for use in safety critical
applications. Eg. ABS braking systems, power
steering, life support systems and critical care
medical equipment. Please contact sales
representative if more clarification is needed.
•
Easy to Mount
•
No Signal Adjustment required
•
Small Size
•
Operating Temperature
°
°
-10°C to 85°C
•
TTL Compatible
•
Single 5V Supply
Ordering Information
AEDB-9140 Option
Theory of Operation
The AEDB-9140 are emitter/
detector modules. Coupled
with a codewheel, these
modules translate the rotary
motion of a shaft into a three-
channel digital output.
As seen in Figure 1, the
modules contain a single Light
Emitting Diode (LED) as its
light source. The light is
collimated into a parallel beam
by means of a single
polycarbonate lens located
directly over the LED.
Opposite the emitter is the
integrated detector circuit. This
IC consists of multiple sets of
photodetectors and the signal
processing circuitry necessary
to produce the digital
waveforms.
Resolutions
(Cycle/Rev)
C - 100 CPR
E - 200 CPR
F - 256 CPR
G - 360 CPR
H - 400 CPR
A - 500 CPR
Shaft Diameter*
02 - 3mm
04 - 5/32 in
05 - 3/16 in
06 - 1/4 in
11 - 4mm
12 - 6mm
13 - 8mm
14 - 5mm
Three Channel Encoder Modules with Codewheel, 11 mm Optical Radius
* Please contact factory for other shaft diameters
Available Options
Part No
CPR
Shaft Diameter Options
02
04
•
•
•
•
•
•
•
•
•
•
•
05
06
•
•
•
11
12
•
•
•
•
13
•
•
•
•
•
•
14
AEDB-9140
C
E
F
G
H
A
The codewheel rotates between
the emitter and detector,
causing the light beam to be
interrupted by the pattern of
spaces and bars on the
codewheel.
The photodiodes which detect
these interruptions are
arranged in a pattern that
corresponds to the radius and
design of the code-wheel.
These detectors are also
spaced such that a light period
on one pair of detectors
corresponds to a dark period
on the adjacent pair of
detectors.
The photodiode outputs are
then fed through the signal
processing circuitry resulting
in A, Abar, B, Bbar, I and
Ibar. Comparators receive
these signals and produce the
final outputs for channels A
and B. Due to this integrated
phasing technique, the digital
output of channel A is in
quadrature with that of
channel B (90 degrees out of
phase).
Block Diagram
Figure 1.
2
Output Waveforms
Figure 2.
Definitions
Note: Refer to Figure 2
Count (N): The number of bar
and window pairs or counts
per revolution (CPR) of the
codewheel.
One Cycle (C): 360 electrical
degrees (°e), 1 bar and
window pair.
One Shaft Rotation: 360
mechanical degrees, N cycles.
Position Error (∆Θ): The
normalized angular difference
between the actual shaft
position and the position
indicated by the encoder cycle
count.
Cycle Error (∆C): An
indication of cycle uniformity.
The difference between an
observed shaft angle which
gives rise to one electrical
cycle, and the nominal angular
increment of 1/N of a
revolution.
Pulse Width (P): The number
of electrical degrees that an
output is high during 1 cycle.
This value is nominally 180°e
or 1/2 cycle.
Pulse Width Error (∆P): The
deviation, in electrical degrees,
of the pulse width from its
ideal value of 180°e.
State Width (S): The number
of electrical degrees between a
transition in the output of
channel A and the neighboring
transition in the output of
channel B. There are 4 states
per cycle, each nominally 90°e.
State Width Error (∆S): The
deviation, in electrical degrees,
of each state width from its
ideal value of 90°e.
Phase (f): The number of
electrical degrees between the
center of the high state of
channel A and the center of
the high state of channel B.
This value is nominally 90°e
for quadrature output.
Phase Error (∆φ): The
deviation of the phase from its
ideal value of 90°e.
Direction of Rotation: When
the codewheel rotates in the
clockwise direction viewing
from top of the module
(direction from V to G),
channel A will lead channel B.
If the codewheel rotates in the
opposite direction, channel B
will lead channel A.
Optical Radius (Rop): The
distance from the codewheel’s
center of rotation to the
optical center (O.C) of the
encoder module.
Index Pulse Width (Po): The
number of electrical degrees
that an index is high during
one full shaft rotation. This
value is nominally 90°e or 1/4
cycle.
3
Absolute Maximum Ratings
Parameter
Storage Temperature
Operating Temperature
Supply Voltage
Output Voltage
Output Current per Channel, Iout
Symbol
T
S
T
A
V
CC
V
O
I
OUT
Minimum
-10
-10
-0.5
-0.5
-1.0
Typical
Maximum
85
85
7
V
CC
18
Units
°C
°C
Volts
Volts
mA
Notes
Recommended Operating Conditions
Parameter
Temperature
Supply Voltage
Load Capacitance
Frequency
Shaft Perpendicularity Plus Axial Play
Shaft Eccentricity Plus Radial Play
Symbol
T
A
V
CC
C
L
f
Min.
-10
4.5
5.0
Typ.
Max.
85
5.5
100
100
± 0.20
(± 0.008)
Units
°C
Volts
pF
kHz
mm
(in.)
Ripple < 100mVp-p
2.7 kΩ pull-up
Velocity (rpm) x N/60
Refer to Mounting
Consideration
Notes
± 0.04
mm
(± 0.0015) (in.)
Electrical Characteristics
Electrical Characteristics Over the Recommended Operating Range. Typical Values at 25°C.
Parameter
Supply Current
High Level Output Voltage
Low Level Output Voltage
Rise Time
Fall Time
Symbol
I
CC
V
OH
V
OL
t
r
t
f
180
50
Minimum Typical
30
2.4
0.4
57
Maximum Units
85
mA
V
V
ns
ns
Typ. I
OH
= -0.5 mA
Typ. I
OL
= 10 mA
C
L
= 25 pF
R
L
= 2.7 kΩ pull-up
Notes
Note: Typical values specified at Vcc = 5.0 V and 25 °C
4
Encoding Characteristics
Encoding Characteristics Over the Recommended Operating Conditions and Recommended Mounting Tolerances unless
otherwise specified.
Parameter
Cycle Error
Pulse Width Error
Logic State Width Error
Phase Error
Position Error
Index Pulse Width
CH I rise after
CH B or CH A fall
CH I fall after
CH A or CH B rise
-10°C to + 85°C
-10°C to + 85°C
Symbol
∆C
∆P
∆S
∆φ
∆Θ
Po
t
1
t
2
60
10
10
Minimum
Typical
3
7
5
2
10
90
100
300
Maximum
10
30
30
15
40
120
1000
1000
Units
°e
°e
°e
°e
min. of arc
°e
ns
ns
Notes
Electrical Interface
To insure reliable encoding
performance, the AEDB-9140
three channel encoder modules
require 2.7 kΩ (± 10%) pull-up
resistors on output pins 2, 3,
and 5 (Channels A, I and B)
as shown in Figure 3. These
pull-up resistors should be
located as close to the encoder
module as possible (within 4
feet). Each of the three
encoder module outputs can
drive a single TTL load in this
configuration.
Figure 3.
5
嵌入式系统
