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
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.
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.
The AEDR-8000 Encoder series employs reflective
technology for rotary and linear movement control.
The encoder houses an LED light source and a photo-
detecting circuitry in a single package.
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.
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.
Note: All specifications are subject to change without prior notification.
AEDR-8000 Series
Reflective Surface Moun t Optical Encoder
Data Sheet
2
Block Diagram of AEDR-8000 Encoder 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.
State Width Error (DS): The
deviation of state width, in
electrical degrees, from its ideal
value of 90°e.
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.
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).
SIGNAL
PROCESSING
CIRCUITRY
V
CC
CH A
V
LED
GND
CH B
GND
RCODEWHEEL
or
CODESTRIP
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
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.
3
Line Density: The number of
window and bar pairs per unit
length, expressed in either lines
per inch (LPI) or lines per mm
(LPmm).
Optical Radius (Rop): The
distance between the codewheel
center and the centerline
between the two domes of the
encoder.
Output Waveform
CH. A
ALL FOUR STATES (S1 to S4)
ARE MAINTAINED.
CH. B
S1
P
C
S2 S3
CODEWHEEL ROTATION OR LINEAR MOVEMENT
AMPLITUDE
S4 f
SHAFT
RADIAL (ER)
TANGENTIAL (ET)
AEDR-8000
CODEWHEEL
SHAFT
ANGULAR (EA)
AEDR-8000
CODEWHEEL
Gap (G): The distance from the
surface of the encoder to the
surface of codewheel or
codestrip.
Specular Reflectance (Rf): 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).
Radial and Tangential
Misalignment Error (ER, ET):
For rotary motion, mechanical
displacement in the radial and
tangential directions relative to
the nominal alignment.
Angular Misalignment Error
(EA): Angular displacement of
the encoder relative to the
tangential line.
4
Absolute Maximum Ratings
Storage Temperature, TS-40°C to 85°C
Operating Temperature, TA-20°C to 85°C
Supply Voltage, VCC -0.5 V to 7 V
Output Voltage, VO-0.5 V to VCC
Output Current per Channel, IOUT -1.0 mA to 8 mA
ESD 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. Min. Typ. Max. Units Notes
Temperature TA02585°C
Supply Voltage VCC 4.5 5.0 5.5 V Ripple < 100 mVp-p
LED Current ILED 13 15 18 mA See note 1
Load Capacitance CL100 pF 2.7 kΩ Pull-Up
Count Frequency f 30 kHz See note 2
Radial Misalignment ER±0.38 mm (in.)
(±0.015)
Tangential Misalignment ET± 0.38 mm (in.)
(± 0.015)
Angular Misalignment EA0± 1.5 deg.
Codewheel/Strip Tilt CT01deg.
Codewheel/Strip Gap G 1.0 (0.04) 2.0 (0.08) 2.5 (0.10) 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 Notes
Pulse Width Error DP15 55 °eAEDR-8010-K
Pulse Width Error (Ch. A, Ch. B) DP15, 25 55, 75 °eAEDR-8000-K
16 75 AEDR-8100-P
16 75 AEDR-8100-Q
Phase Error Df 12 60 °eAEDR-8000-K
10 60 AEDR-8100-P
10 60 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.
5
Electrical Characteristics
Characteristics over recommended operating conditions at 25°C.
Parameter Symbol Min. Typ. Max. Unit Notes
Detector Supply Current Icc 2.2 5.0 mA
High Level Output Voltage VOH 2.4 V IOH = -0.2 mA
Low Level Output Voltage VOL 0.4 V IOL = 8.0 mA
Rise Time tr500 ns CL = 25 pF
Fall Time tf100 ns RL = 2.7 kΩ
Recommended Codewheel and Codestrip Characteristics
Parameter Symbol Min. Max. Unit Notes
Window/Bar Ratio Ww/Wb 0.9 1.1
Window/Bar Length LW1.80 (0.071) 2.31 (0.091) mm (inches)
Specular Reflectance Rf60 85 Reflective area. See note 1.
–10 Nonreflective area
2.95 (75) AEDR-80X0-K
5.91 (150) AEDR-8100-P
7.09 (180) AEDR-8100-Q
Optical Radius Rop 11 –mm Recommended value
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
(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.
W
b
W
w
W
w
W
b
L
w
R
op
L
w
6
Package Outline Drawing
6.2
4.4
TOP VIEW
3.2 2.7
1.0
1.5
SIDE VIEW (LOW RESOLUTION) SIDE VIEW (HIGH RESOLUTION)
ALL DIMENSIONS ARE IN MILLIMETERS
TOLERANCE X.XX ± 1.5 mm
NC
GND
CH A
VCC
VLED
NC
CH B
GND
0.62
1.28
0.64
0.4
1.02
0.4
1.54
0.84
1.62
BOTTOM VIEW
7
Encoder Orientation
The AEDR-8000 series is
designed such that both the LED
and detector IC should be placed
Mounting Consideration
Direction of Codewheel Rotation
With the emitter side of the
encoder placed closer to the
codewheel centre, Channel A
parallel to the window/bar
orientation, as shown. As such,
the encoder is tolerant against
Viewed from Top
CODESTRIP
DIRECTION OF
RADIAL PLAY
CODEWHEEL
DIRECTION OF
RADIAL PLAY
CH. A LEADS
CH. B
EMITTER
ANTI-CLOCKWISE
CH. B LEADS
CH. A
EMITTER
CLOCKWISE
leads Channel B when the
codewheel rotates anti-clockwise
and vice versa.
radial play of ± 0.38 mm. The
emitter side should be placed
closer to the rotating shaft.
ROP
11.00 mm (0.433 IN) < ROP < ∞
CODEWHEEL/CODESTRIP
GAP
8
Recommended Lead-Free Reflow Soldering Temperature Profile
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 75 150 180
Color Clear Red Amber
300
250
200
150
100
50
0122456687108129 150 171 192 213 235 256 278 299 320 341 363 384
255°C
250°C
217°C
40°C
125°C
10 - 20 SEC.
120 SEC. MAX. 60 - 150 SEC.
TIME (SEC.)
HEAT UP SOLDER PASTE DRY SOLDER REFLOW COOL DOWN
TEMPERATURE (°C)
9
Ordering Information
AEDR-8 0 Option
PCB Thickness Number of Packaging Lines per Inch Shipping Units
0 - 1.5 mm (Low Channels 1 - Tape and K - 75 LPI 0 - 1000 pcs
Resolution) 1 - One Channel Reel P - 150 LPI 1 - 500 pcs
1 - 1.0 mm (High 0 - Two Channels Q - 180 LPI 2 - 100 pcs
Resolution)
Note: Encoders are packed in tape of quantity 1000 pcs or 500 pcs or 100 pcs.
Available Options
Resolution Shipping Units
K – P – Q – 0 – 1 – 2 –
Encoder 75 LPI 150 LPI 180 LPI 1000 pcs 500 pcs 100 pcs
AEDR-8000 * * * *
AEDR-8010 * *
AEDR-8100 * * * *
AEDR-8100 * * *
For product information and a complete list of distributors, please go to our website: www.avagotech.com
Avago, Avago Technologies, and the A logo are trademarks of Avago Technologies Limited in the United States and other countries.
Data subject to change. Copyright © 2006 Avago Technologies Pte. All rights reserved.
5989-3067EN July 2, 2006
