Agilent AEDR-8000 Series Encoders
Reflective Surface Mount Optical Encoder
Data Sheet
Description
By introducing an additional PCB
top-up thickness attached to the
encoder, the AEDR-8000 Encoder
series could easily solve the height
issue in various applications.
Furthermore, this great feature is
enhanced with the offering of
different height profile options.
In adding on to the main features,
The AEDR-8000 Encoder series
offers two-channel quadrature
digital outputs (TTL compatible)
where signal could be interfaced
directly with most of the signal
processing circuitries. Thus, it’s
bound to reduce the design time
of an application.
Direct Replacement of HEDR-8000
Encoder series is now possible
with the AEDR-8000 Encoder
series. Such migration is always
simple and easy due to the perfect
matching of the height profiles as
well as same footprints in both
encoder series.
Applications
The AEDR-8000 Encoder series
provides motion sensing at a
competitive price, making it ideal
for high volume applications. Its
small size and surface mount
package make it ideal for printers,
copiers, card readers and many
consumer products, particularly
where space and weight are
design constraints.
The AEDR-8000 Encoder series
employs reflective technology for
rotary and linear movement
control. The encoder houses an
LED light source and a photodetecting circuitry in a single
package.
Note: All specifications are subject to change without prior notification.
Features
• Reflective technology
• Surface mount small outline
leadless package
• Direct replacement of HEDR-8000
encoder
• Single channel incremental output
• Two channels quadrature outputs
for direction sensing
• Single 5 V supply, TTL compatible
output
• -20°C to 85°C absolute operating
temperature
• Lead-free package
• Encoding resolution options:
75, 150 and 180 (lines/inch) or
2.95, 5.91, 7.09 (lines/mm)
• PCB height profile options:
1.0 mm PCB thickness
1.5 mm PCB thickness
Block Diagram of AEDR-8000 Encoder
VLED
R
GND
CODEWHEEL
or
CODESTRIP
VCC
State Width Error (DS): The
deviation of state width, in
electrical degrees, from its ideal
value of 90°e.
CH A
CH B
SIGNAL
PROCESSING
CIRCUITRY
Phase (f): The number of
electrical degrees between the
center of high state of Channel A
and the center of high state of
Channel B. Nominally 90°e.
GND
Theory of Operation
The AEDR 8000 Encoder series
combines an emitter and a
detector in a single surface
mount leadless package. When
used with a codewheel or linear
codestrip, the encoder translates
rotary or linear motion into
digital outputs. As seen in the
block diagram, the AEDR-8000
Encoder series consists of three
major components: a light
emitting diode (LED) light
source, a detector IC consisting
photodiodes, and lens to focus
light beam from the emitter as
well as light falling on the
detector.
The operation of the encoder is
based on the principle of optics
where the detector photodiodes
sense the absence and presence
of light. In this case, the rotary/
linear motion of an object being
Definitions
State Width (S): The number of
electrical degrees between a
transition in Channel A and the
neighboring transition in
Channel B. There are 4 states
per cycle, each nominally 90°e.
monitored is converted to
equivalent light pattern via the
use of codewheel/codestrip. As
shown in the above diagram, the
reflective area (window) of the
codewheel (or codestrip) reflects
light back to the photodetector
IC, whereas no light is reflected
by the non-reflective area (bar).
An alternating light and dark
pattern, corresponding to the
window and bar, falls on the
photodiodes as the codewheel
rotates. The moving light pattern
is exploited by the detector
circuitry to produce digital
outputs representing the
rotation of the codewheel. When
the codewheel is coupled to a
motor, the encoder outputs are
then a direct representation of
the motor rotation. The same
concept applies to the use of a
codestrip to detect linear
motion.
Phase Error (Df): The deviation
of phase, in electrical degrees,
from its ideal value of 90°e.
Pulse Width (P): The duration
of high state of the output, in
electrical degrees, within one
cycle. Nominally 180°e or half a
cycle.
Pulse Width Error (DP): The
deviation of pulse width, in
electrical degrees, from its ideal
value of 180°e.
Count (N): The number of
window and bar pairs per
revolution (CPR) of codewheel.
For linear codestrip, defined as
the number of window and bar
pairs per unit length (lines per
inch [LPI] or lines per mm
[LPmm]).
One Cycle (C): 360 electrical
degrees (°e). Equivalent to one
window and bar pair.
One Shaft Rotation: 360
mechanical degrees. Also
equivalent to N counts
(codewheel only).
2
Line Density: The number of
window and bar pairs per unit
length, expressed in either lines
per inch (LPI) or lines per mm
(LPmm).
Radial and Tangential
Misalignment Error (ER, E T):
For rotary motion, mechanical
displacement in the radial and
tangential directions relative to
the nominal alignment.
Gap (G): The distance from the
surface of the encoder to the
surface of codewheel or
codestrip.
Specular Reflectance (R f): The
amount of incident light
reflected by a surface.
Quantified in terms of the
percentage of incident light. A
spectrometer can be used to
measure specular reflectance of
a surface (contact factory for
more information).
Optical Radius (Rop): The
distance between the codewheel
center and the centerline
between the two domes of the
encoder.
Angular Misalignment Error
(EA ): Angular displacement of
the encoder relative to the
tangential line.
Output Waveform
C
ALL FOUR STATES (S1 to S4)
ARE MAINTAINED.
P
AMPLITUDE
CH. A
S1
S2
S3
S4
f
CH. B
CODEWHEEL ROTATION OR LINEAR MOVEMENT
RADIAL (ER)
ANGULAR (EA)
TANGENTIAL (ET)
AEDR-8000
3
AEDR-8000
SHAFT
SHAFT
CODEWHEEL
CODEWHEEL
Absolute Maximum Ratings
Storage Temperature, TS
Operating Temperature, TA
Supply Voltage, VCC
Output Voltage, VO
Output Current per Channel, IOUT
ESD
-40°C to 85°C
-20°C to 85°C
-0.5 V to 7 V
-0.5 V to VCC
-1.0 mA to 8 mA
Human Body Model JESD22-A114-A Class 2
Machine Model JESD22-A115-A Class B
Notes:
1. Exposure to extreme light intensity (such as from flashbulbs or spotlights) may cause permanent damage to the device.
2. CAUTION: It is advised that normal static precautions should be taken when handling the encoder in order to avoid damage and/or degradation
induced by ESD.
3. Proper operation of the encoder cannot be guaranteed if the maximum ratings are exceeded.
Recommended Operating Conditions
Parameter
Sym.
Temperature
TA
Supply Voltage
V CC
LED Current
I LED
Load Capacitance
CL
Count Frequency
f
Radial Misalignment
ER
Tangential Misalignment
ET
Angular Misalignment
Codewheel/Strip Tilt
Codewheel/Strip Gap
EA
CT
G
Min.
0
4.5
13
1.0 (0.04)
Typ.
25
5.0
15
0
0
2.0 (0.08)
Max.
85
5.5
18
100
30
±0.38
(±0.015)
± 0.38
(± 0.015)
± 1.5
1
2.5 (0.10)
Units
°C
V
mA
pF
kHz
mm (in.)
Notes
Ripple < 100 mVp-p
See note 1
2.7 kΩ Pull-Up
See note 2
mm (in.)
deg.
deg.
mm (in.)
Note:
1. Refer to “LED Current Limiting Resistor” on page 5.
2. Count frequency = velocity (RPM) x N/60.
Encoding Characteristics
Encoding characteristics over the recommended operating condition and mounting conditions.
Parameter
Symbol
Typical
Maximum
Unit
Pulse Width Error
DP
15
55
°e
Pulse Width Error (Ch. A, Ch. B)
DP
15, 25
55, 75
°e
16
75
16
75
Phase Error
Df
12
60
°e
10
60
10
60
Notes
AEDR-8010-K
AEDR-8000-K
AEDR-8100-P
AEDR-8100-Q
AEDR-8000-K
AEDR-8100-P
AEDR-8100-Q
Note: Typical values represent the encoder performance at typical mounting alignment, whereas the maximum values represent the encoder
performance across the range of recommended mounting tolerance.
4
Electrical Characteristics
Characteristics over recommended operating conditions at 25°C.
Parameter
Symbol
Min.
Typ.
Detector Supply Current
Icc
2.2
High Level Output Voltage
VOH
2.4
Low Level Output Voltage
VOL
Rise Time
tr
500
Fall Time
tf
100
Max.
5.0
0.4
Unit
mA
V
V
ns
ns
Notes
IOH = -0.2 mA
IOL = 8.0 mA
CL = 25 pF
RL = 2.7 kΩ
Recommended Codewheel and Codestrip Characteristics
Wb
Ww
Lw
Rop
Lw
Ww W b
Parameter
Window/Bar Ratio
Window/Bar Length
Specular Reflectance
Symbol
Ww/Wb
LW
Rf
Optical Radius
Rop
Min.
Max.
0.9
1.1
1.80 (0.071)
2.31 (0.091)
60
85
–
10
2.95 (75)
5.91 (150)
7.09 (180)
11
–
Unit
mm (inches)
mm
Notes:
1. Measurements from TMA µScan meter. Contact factory for more information.
2. Contact factory for more information on compatibility of codewheel/strip.
LED Current Limiting Resistor
A resistor to limit current to the
LED is required. The
recommended value is 220 Ω
(±10 %) and the resistor should be
placed in series between the 5 V
supply and pin 3 of the device
5
Notes
(Vled). This will result in an LED
current of approximately 15 mA.
Moisture Sensitive Level
The AEDR-8000 series is
specified to moisture sensitive
level (MSL) 3.
Reflective area. See note 1.
Nonreflective area
AEDR-80X0-K
AEDR-8100-P
AEDR-8100-Q
Recommended value
Package Outline Drawing
6.2
4.4
TOP VIEW
0.62
1.02
0.4
NC
VLED
1.28
1.54
GND
NC
0.64
0.84
1.62
CH B
CH A
GND
VCC
0.4
BOTTOM VIEW
2.7
3.2
1.5
SIDE VIEW (LOW RESOLUTION)
ALL DIMENSIONS ARE IN MILLIMETERS
TOLERANCE X.XX ± 1.5 mm
6
1.0
SIDE VIEW (HIGH RESOLUTION)
Encoder Orientation
The AEDR-8000 series is
designed such that both the LED
and detector IC should be placed
parallel to the window/bar
orientation, as shown. As such,
the encoder is tolerant against
radial play of ± 0.38 mm. The
emitter side should be placed
closer to the rotating shaft.
CODEWHEEL
CODESTRIP
DIRECTION OF
RADIAL PLAY
DIRECTION OF
RADIAL PLAY
Mounting Consideration
CODEWHEEL/CODESTRIP
GAP
ROP
11.00 mm (0.433 IN) < ROP < ∞
Direction of Codewheel Rotation
With the emitter side of the
encoder placed closer to the
codewheel centre, Channel A
leads Channel B when the
codewheel rotates anti-clockwise
and vice versa.
ANTI-CLOCKWISE
CLOCKWISE
EMITTER
EMITTER
CH. A LEADS
CH. B LEADS
CH. B
CH. A
Viewed from Top
7
Recommended Lead-Free Reflow Soldering Temperature Profile
10 - 20 SEC.
300
255°C
250°C
TEMPERATURE (°C)
250
217°C
200
120 SEC. MAX.
60 - 150 SEC.
150
125°C
100
50
40°C
0
1
22
45
66
87
108
129
150
171
192
213
235
256
278
299
320
341
363
TIME (SEC.)
HEAT UP
SOLDER PASTE DRY
SOLDER REFLOW
COOL DOWN
Preheat Temperature 40°C to 125°C = 120 sec. max.
Temperature Maintain Above 217°C = 60 – 150 sec.
Peak Temperature
= 255 ± 5°C
Time Above 250°C
= 10 – 20 sec.
Note: Due to treatment of high temperature, AEDR-8000 transparent compound is expected to turn
yellow after IR reflow.
Resolution Indicator
Since the encoder is too small to
imprint resolution marking on
its package, color-coding the
package is employed to
differentiate resolutions. The
details are:
LPI
Color
8
75
Clear
150
Red
180
Amber
384
Ordering Information
AEDR-8
PCB Thickness
0 - 1.5 mm (Low
Resolution)
1 - 1.0 mm (High
Resolution)
0
Number of
Channels
1 - One Channel
0 - Two Channels
Option
Packaging
1 - Tape and
Reel
Lines per Inch
K - 75 LPI
P - 150 LPI
Q - 180 LPI
Note: Encoders are packed in tape of quantity 1000 pcs or 500 pcs or 100 pcs.
Available Options
Encoder
AEDR-8000
AEDR-8010
AEDR-8100
AEDR-8100
9
Resolution
K–
P–
Q–
75 LPI 150 LPI
180 LPI
*
*
*
*
Shipping Units
0–
1–
2–
1000 pcs
500 pcs 100 pcs
*
*
*
*
*
*
*
*
*
Shipping Units
0 - 1000 pcs
1 - 500 pcs
2 - 100 pcs
www.agilent.com/semiconductors
For product information and a complete list of
distributors, please go to our web site.
For technical assistance call:
Americas/Canada: +1 (800) 235-0312 or
(916) 788-6763
Europe: +49 (0) 6441 92460
China: 10800 650 0017
Hong Kong: (+65) 6756 2394
India, Australia, New Zealand: (+65) 6755 1939
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Singapore, Malaysia, Vietnam, Thailand,
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Taiwan: (+65) 6755 1843
Data subject to change.
Copyright © 2005 Agilent Technologies, Inc.
May 24, 2005
5989-3067EN