AEDB-9340 Series
1250/2500 CPR Commutation Encoder Modules
with Codewheel
Data Sheet
Description
The AEDB-9340 optical encoder series are six-channel
optical incremental encoder modules with codewheel.
The encoder is compliant to RoHS directive and had
been declared as a lead free product. When used with
codewheel, these modules detect rotary position. Each
module consists of a collimated LED source and detector
IC enclosed within a small plastic package. Due to
highly collimated light source and unique photo detec-
tor array designs, these modules are extremely tolerant
to mounting misalignment.
The AEDB-9340 optical encoder has integrated commu-
tation output (U, V, W), two-channel quadrature outputs
plus a third channel index output (A, B, I). This ungated
index output is a positive index pulse that is generated
once for each full rotation of the codewheel.
The AEDB-9340 series optical encoder is designed for
use with a codewheel that has an optical radius of
15 mm (0.590 inch) for 1250/2500 CPR, 12.3 mm (0.484
inch) for 1024/2048 CPR and 12 mm (0.472 inch) for 1000/
2000 CPR.
The quadrature, index, commutation signals and power
supplied to encoder are accessed through eight
0.46 mm square male connector pins located on 1.27 mm
(pitch).
The AEDB-9340 optical encoder provides advanced
motion control detection with integrated commutation
outputs (U, V, and W). It is equivalent to those produced
by Hall Switches, thus making it ideal for servo motor
application. With the AEDB-9340 solution, the system will
be more compact, have reduced alignment time with
usage of alignment jig, thus making assembly process
much easier for housed encoder integration. It has
superior switching accuracy due to much lower
hysteresis when compared to a Hall Switches. The com-
mutation signals can be generated for Brushless DC
motor of different rotor pole-pairs by simply changing
with matching pole-pair codewheel.
Features
• Two-channel quadrature output with ungated index
pulse (A, B, I)
• Three-channel integrated commutation output (U, V, W)
• Up to 2500 Cycles Per Revolution (CPR)
• Easy assembly with alignment jig
• Designed to fit into circular shaped housing
• Up to 150 kHz frequency response
• –10°C to 85°C operating temperature
• TTL compatible
• Single 5 V supply
• Integrated feedback device for Brushless DC Motor
Applications
Typical applications include industrial printers, plotters,
tape drives, and industrial and factory automation
equipment.
Note: Avago Technologies encoders are not recommended
for use in safety critical applications, e.g., ABS braking
systems, power steering, life support systems and critical
care medical equipment. Please contact sales representative
if more clarification is needed.
Theory of Operation
The AEDB-9340 optical encoder is a emitter-detector
module. Coupled with codewheel, these modules trans-
late the rotary motion of a shaft into six-channel digital
output.
The modules contain a single Light Emitting Diode
(LED) as light source. The light is collimated into a
parallel beam by means polycarbonate lens located
directly over the LED. Opposite the emitter is a detector
IC. This IC consists of multiple sets of photo detectors
and signal processing circuitry necessary to produce
digital waveforms output.
The codewheel rotates between the emitter and detec-
tor, causing the light beam to be interrupted by pattern
of spaces and bars on the codewheel.
The Photodiodes that detect these interruptions are
arranged in a pattern that corresponds to the radius
and design of the codewheel. These detectors are also
spaced in such away that light period on one pair of
detectors corresponds to dark period on adjacent pair
of detectors.
The photodiode outputs are then fed through the signal
processing circuitry resulting in A, A, B, B, I, and I.
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). The commutation feedback (U, V, W) signals
are generated based on the codewheel design.
Cycle Error (DC):
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 (D P):
The deviation, in electrical
degrees, of the pulse width from its ideal value of 180°e.
State Width (S):
The numbers of electrical degrees
between transitions 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 (D S):
The deviation, in electrical
degrees, of each state width from its ideal value of 90°e.
Commutation Accuracy (D I):
The deviation, in
mechanical degrees, after shaft rotates passing the
reference point (Index channel) to the first Channel-U
pulse. The measurement from middle of Channel-I to
rising edge of Channel-U.
Phase (f):
The numbers 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.
This value is nominally 90°e for quadrature output.
Phase Error (Df ):
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 pin U to B), channel A will lead
channel B. If the codewheel rotates in the opposite
direction (direction from pin B to U), 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 with reference to channel
A or channel B during one full shaft rotation.
Definitions
Cycles (N):
The number of electrical cycles per
revolution (CPR). Note: CPR refers to the raw signal from
encoder, that is the cycles before 4x decode.
One Cycle:
360 electrical degrees (°e).
One Shaft Rotation:
360 mechanical degrees.
2
AEDB-9340 Technical Specifications
Absolute Maximum Ratings
Parameter
Storage Temperature
Operating Temperature
Supply Voltage
Symbol
T
S
T
A
V
CC
Min.
-40
-10
-0.5
Max.
85
85
7
Units
°C
°C
Volts
Notes
Recommended Operating Conditions
Parameter
Temperature
Supply Voltage (Detector)
Operating Frequency
1250 CPR
2500 CPR
Shaft Radial Play Plus Eccentricity
Shaft Axial Play
Min.
-10
4.5
Typ.
25
5.0
Max.
85
5.5
75
150
±0.025
±0.100
Units
°C
Volts
kHz
kHz
mm TIR
mm
Notes
Ripple < 100 mVpp
Velocity (rpm) x N/60
Electrical Characteristics
Electrical Characteristics over Recommend Operating Range, Typical at 25°C
Parameter
Supply Current
High Level Output Voltage
Low Level Output Voltage
Rise Time
Fall Time
Loading Capacitance
Symbol
I
CC
V
OH
V
OL
t
r
t
f
C
LOAD
Min.
40
2.4
Typ.
60
Max.
80
0.4
200
20
47
Units
mA
V
V
ns
ns
pF
Notes
C
L
= 14 pF
Encoding Characteristics
Encoding Characteristics over the Recommended Operating Conditions and Mounting tolerances. These charac-
teristics include codewheel contribution. The typical values are average over the full rotation of the codewheel
tested at 25°C, 500 RPM, 5V.
Parameter
Pulse Width Error
Logic State Width Error
Phase Error
Cycle Error
Position Error
Index Pulse Width
1000/1024/1250 CPR
2000/2048/2500 CPR
3
Symbol
DP
DS
Df
DC
DQ
P
0
P
0
Minimum
Typical
7
5
2
20
20
150
300
Maximum
50
50
25
50
50
360
540
Units
°e
°e
°e
°e
min. of arc
°e
°e
90
180
Commutation Characteristics (Channel U, V, W)
Encoding Characteristics over the Recommended Operating Conditions and Mounting Conditions. These
characteristics include codewheel contribution. The typical values are average over the full rotation of the
codewheel.
Parameter
Commutation Format
Commutation Accuracy
(Middle of Channel I to Channel U)
Commutation Accuracy
(Channel U,V and W)
Symbol
Minimum
Maximum
Units
Three Phase 4, 6, or 8 poles
DI
D
UVW
-1
-2
+1
+2
°mechanical
°mechanical
Device Pinout
Pin #1 start from left side.
Pin
1
2
3
4
5
6
7
8
Function
U
I
V
W
Ground
V
CC
A
B
PIN #8
PIN #1
4
Package Dimensions
40.12
28.4
C
L
R 20.00
1.50
∅
1.000
∅
2
1.11
1.1
7.4
12.6
3.5
∅
1.000
R 22.00
0.50
19.75
33.4
CHAMFER 45° x 1.60
TOP VIEW
Note:
All dimensions are given in mm.
Figure 1a. 1000/1024/1250/2000/2048/2500 CPR encoder module dimensions
5
