ESD WARNING: NORMAL HANDLING PRECAUTIONS SHOULD BE TAKEN TO AVOID STATIC DISCHARGE.
Description
The HEDS-5500/5540, HEDS-5600/5640, and HEDM-
5500/5600 are high performance, low cost, two and
three channel optical incremental encoders. These
encoders emphasize high reliability, high resolution,
and easy assembly.
Each encoder contains a lensed LED source, an inte-
grated circuit with detectors and output circuitry, and
a codewheel which rotates between the emitter and
detector IC. The outputs of the HEDS-5500/5600 and
HEDM-5500/ 5600 are two square waves in quadrature.
The HEDS-5540 and 5640 also have a third channel
index output in addition to the two channel quadrature.
This index output is a 90 electrical degree, high true
index pulse which is generated once for each full
rotation of the codewheel.
The HEDS series utilizes metal codewheels, while the
HEDM series utilizes a film codewheel allowing for
resolutions to 1024 CPR. The HEDM series is nont
available with a third channel index.
These encoders may be quickly and easily mounted to
a motor. For larger diameter motors, the HEDM-5600,
and HEDS-5600/5640 feature external mounting ears.
The quadrature signals and the index pulse are accessed
through five 0.025 inch square pins located on 0.1 inch
centers.
Standard resolutions between 96 and 1024 counts per
revolution are presently available. Consult local Avago
sales representatives for other resolutions.
HEDM-550x/560x
HEDS-550x/554x, HEDS-560x/564x
Note: Avago 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.
Features
•Two channel quadrature output with optional index pulse
•Quick and easy assembly
•No signal adjustment required
•External mounting ears available
•Low cost
•Resolutions up to 1024 counts per revolution
•Small size
•–40°C to 100°C operating temperature
•TTL compatible
•Single 5 V supply
HEDM-550x/560x
Quick Assembly Two and Three Channel
Optical Encoders
Data Sheet
Applications
The HEDS-5500, 5540, 5600, 5640, and the HEDM-
5500, 5600 provide motion detection at a low cost,
making them ideal for high volume applications. Typical
applications include printers, plotters, tape drives,
positioning tables, and automatic handlers.
2
Package Dimensions
HEDS-5500/5540, HEDM-5500
*Note: For the HEDS-5600 and HEDM-5600, Pin #2 is a No Connect. For the HEDS-5640, Pin #2 is CH. I, the index output.
HEDS-5600/5640, HEDM-5600
*Note: For the HEDS-5500 and HEDM-5500, Pin #2 is a No Connect. For the HEDS-5540, Pin #2 is CH. I, the index output.
3
Theory of Operation
The HEDS-5500, 5540, 5600,
5640, and HEDM-5500, 5600
translate the rotary motion of a
shaft into either a two- or a three-
channel digital output.
As seen in the block diagram,
these encoders 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.
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
codewheel. 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, A, B and B
(also I and I in the HEDS-5540
and 5640). 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).
In the HEDS-5540 and 5640, the
output of the comparator for I
and I is sent to the index
processing circuitry along with
the outputs of channels A and B.
Block Diagram
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 (φ): 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.
The final output of channel I is an
index pulse PO which is generated
once for each full rotation of the
codewheel. This output PO is a
one state width (nominally 90
electrical degrees), high true
index pulse which is coincident
with the low states of channels A
and B.
Definitions
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 differ-
ence between an observed shaft
angle which gives rise to one
electrical cycle, and the nominal
angular increment of 1/N of a
revolution.
4
Absolute Maximum Ratings
Parameter HEDS-55XX/56XX HEDM-550X/560X
Storage Temperature, TS-40°C to 100°C-40°C to +70°C
Operating Temperature, TA-40°C to 100°C-40°C to +70°C
Supply Voltage, VCC -0.5 V to 7 V -0.5 V to 7 V
Output Voltage, VO-0.5 V to VCC -0.5 V to VCC
Output Current per Channel, IOUT -1.0 mA to 5 mA -1.0 mA to 5 mA
Vibration 20 g, 5 to 1000 Hz 20 g, 5 to 1000 Hz
Shaft Axial Play ±0.25 mm (±0.010 in.) ±0.175 mm (±0.007 in.)
Shaft Eccentricity Plus Radial Play 0.1 mm (0.004 in.) TIR 0.04 mm (0.0015 in.) TIR
Velocity 30,000 RPM 30,000 RPM
Acceleration 250,000 rad/sec2250,000 rad/sec2
Output Waveforms
Direction of Rotation: When the
codewheel rotates in the counter-
clockwise direction (as viewed
from the encoder end of the
motor), channel A will lead
channel B. If the codewheel
rotates in the clockwise direction,
channel B will lead channel A.
Index Pulse Width (PO): The
number of electrical degrees that
an index output is high during
one full shaft rotation. This value
is nominally 90°e or 1/4 cycle.
5
Parameter Symbol Min. Typ. Max. Units Notes
Temperature HEDS Series TA-40 100 °C
Temperature HEDM Series TA-40 70 °Cnon-condensing atmosphere
Supply Voltage VCC 4.5 5.0 5.5 Volts Ripple < 100 mVp-p
Load Capacitance CL100 pF 2.7 kΩ pull-up
Count Frequency f 100 kHz Velocity (rpm) x N/60
Shaft Perpendicularity ±0.25 mm 6.9 mm (0.27 in.) from
Plus Axial Play (HEDS Series) (±0.010) (in.) mounting surface
Shaft Eccentricity Plus 0.04 mm (in.) 6.9 mm (0.27 in.) from
Radial Play (HEDS Series) (0.0015) TIR mounting surface
Shaft Perpendicularity ±0.175 mm 6.9 mm (0.27 in.) from
Plus Axial Play (HEDM Series) (±0.007) (in.) mounting surface
Shaft Eccentricity Plus 0.04 mm (in.) 6.9 mm (0.27 in.) from
Radial Play(HEDM Series) (0.0015) TIR mounting surface
Note: The module performance is guaranteed to 100 kHz but can operate at higher frequencies. 2.7 kΩ pull-up resistors
required for HEDS-5540 and 5640.
Recommended Operating Conditions
Part No. Description Sym. Min. Typ.* Max. Units
HEDS-5500 Pulse Width Error ∆P745°e
HEDS-5600 Logic State Width Error ∆S545°e
(Two Channel) Phase Error ∆φ 220 °e
Position Error ∆Θ 10 40 min. of arc
Cycle Error ∆C35.5 °e
HEDM-5500 Pulse Width Error ∆P1045°e
HEDM-5600 Logic State Width Error ∆S1045°e
(Two Channel) Phase Error ∆φ 215 °e
Position Error ∆Θ 10 40 min. of arc
Cycle Error ∆C37.5 °e
HEDS-5540 Pulse Width Error ∆P535°e
HEDS-5640 Logic State Width Error ∆S535°e
(Three Phase Error ∆φ 215 °e
Channel) Position Error ∆Θ 10 40 min. of arc
Cycle Error ∆C35.5 °e
Index Pulse Width PO55 90 125 °e
CH. I rise after -40°C to +100°Ct
2-300 100 250 ns
CH. A or CH. B fall
CH. I fall after -40°C to +100°Ct
270 150 1000 ns
CH. B or CH. A rise
Note: See Mechanical Characteristics for mounting tolerances.
*Typical values specified at VCC = 5.0 V and 25°C.
Encoding Characteristics
Encoding Characteristics over Recommended Operating Range and Recommended Mounting Tolerances
unless otherwise specified. Values are for the worst error over the full rotation.
6
Electrical Characteristics
Electrical Characteristics over Recommended Operating Range.
Part No. Parameter Sym. Min. Typ.* Max. Units Notes
HEDS-5500 Supply Current ICC 17 40 mA
HEDS-5600 High Level Output Voltage VOH 2.4 V IOH = -40 µA max.
Low Level Output Voltage VOL 0.4 V IOL = 3.2 mA
Rise Time tr200 ns CL = 25 pF
Fall Time tf50 ns RL = 11 kΩ pull-up
HEDS-5540 Supply Current ICC 30 57 85 mA
HEDS-5640 High Level Output Voltage VOH 2.4 V IOH = -200 µA max.
HEDM-5500 Low Level Output Voltage VOL 0.4 V IOL = 3.86 mA
Rise Time tr180 ns CL = 25 pF
Fall Time tf40 ns RL = 2.7 kΩ pull-up
HEDM-5500 Supply Current ICC 30 57 85 mA
HEDM-5600 High Level Output Voltage VOH 2.4 V IOH = -40 µA max.
Low Level Output Voltage VOL 0.4 V IOL = 3.86 mA
Rise Time tr180 ns CL = 25 pF
Fall Time tf40 ns RL = 3.2 kΩ pull-up
*Typical values specified at VCC = 5.0 V and 25°C.
HEDM-5600
7
Electrical Interface
To insure reliable encoding
performance, the HEDS-5540 and
5640 three channel encoders
require 2.7 kΩ (±10%) pull-up
resistors on output pins 2, 3, and
5 (Channels I, A, and B) as shown
in Figure 1. These pull-up
resistors should be located as
close to the encoder as possible
(within 4 feet). Each of the three
encoder outputs can drive a single
TTL load in this configuration.
The HEDS-5500, 5600, and
HEDM-5500, 5600 two channel
encoders do not normally require
pull-up resistors. However, 3.2 kΩ
pull-up resistors on output pins 3
and 5 (Channels A and B) are
recommended to improve rise
times, especially when operating
above 100 kHz frequencies.
Mechanical Characteristics
Parameter Symbol Dimension Tolerance[1] Units
Codewheel Fits These 2 3 4 +0.000 mm
Standard Shaft Diameters 5 6 8 -0.015
5/32 1/8 +0.0000 in
3/16 1/4 -0.0007
Moment of Inertia J 0.6 (8.0 x 10-6) g-cm2 (oz-in-s2)
Required Shaft Length[2] 14.0 (0.55) ±0.5 mm
(±0.02) (in.)
Bolt Circle[3] 2 screw 19.05 ±0.13 mm
mounting (0.750) (±0.005) (in.)
3 screw 20.90 ±0.13 mm
mounting (0.823) (±0.005) (in.)
external 46.0 ±0.13 mm
mounting ears (1.811) (±0.005) (in.)
Mounting Screw Size[4] 2 screw
mounting M 2.5 or (2-56) mm (in.)
3 screw
mounting M 1.6 or (0-80) mm (in.)
external
mounting ears M 2.5 or (2-56) mm (in.)
Encoder Base Plate 0.33 (0.130) mm (in.)
Thickness
Hub Set Screw (2-56) (in.)
Notes:
1. These are tolerances required of the user.
2. The HEDS-55X5 and 56X5, HEDM-5505, 5605 provide an 8.9 mm (0.35 inch) diameter hole through the housing for longer motor
shafts. See Ordering Information.
3. The HEDS-5540 and 5640 must be aligned using the aligning pins as specified in Figure 3, or using the alignment tool as shown in
“Encoder Mounting and Assembly”. See also “Mounting Considerations.”
4. The recommended mounting screw torque for 2 screw and external ear mounting is 1.0 kg-cm (0.88 in-lbs). The recommended
mounting screw torque for 3 screw mounting is 0.50 kg-cm (0.43 in-lbs).
8
Mounting Considerations
The HEDS-5540 and 5640 three
channel encoders and the HEDM
Series high resolution encoders
must be aligned using the aligning
pins as specified in Figure 3, or
using the HEDS-8910 Alignment
Tool as shown in Encoder
Mounting and Assembly.
The use of aligning pins or
alignment tool is recommended
but not required to mount the
HEDS-5500 and 5600. If these
two channel encoders are
attached to a motor with the screw
sizes and mounting tolerances
specified in the mechanical
characteristics section without
any additional mounting bosses,
the encoder output errors will be
within the maximums specified in
the encoding characteristics
section.
The HEDS-5500 and 5540 can be
mounted to a motor using either
the two screw or three screw
mounting option as shown in
Figure 2. The optional aligning
pins shown in Figure 3 can be
used with either mounting option.
The HEDS-5600, 5640, and
HEDM-5600 have external
mounting ears which may be used
for mounting to larger motor base
plates. Figure 4 shows the
necessary mounting holes with
optional aligning pins and motor
boss.
Figure 1. Pull-up Resistors on HEDS-5X40 Encoder Outputs.
Figure 3. Optional Mounting Aids.Figure 2. Mounting Holes.
11.10 / 10.94
(0.438 / 0.431)
2.39 / 2.34
(0.096 / 0.092)
9
Figure 4. Mounting with External Ears.
0.25 (0.010) X
45° CHAMFER
2 PLACES
A Ø 0.15 (0.006)
2.39 / 2.34
(0.096 / 0.092)
11.10 / 10.94
(0.438 / 0.431)
0.8 (0.03) X 45° CHAMFER
O A 0.05 (0.002)
10
3a. Push the hex wrench into the body of the encoder to
ensure that it is properly seated into the code wheel hub set
screws. Then apply a downward force on the end of the hex
wrench. This sets the code wheel gap by levering the code
wheel hub to its upper position.
3b. While continuing to apply a downward force, rotate the
hex wrench in the clockwise direction until the hub set
screw is tight against the motor shaft (The recommended
torque to tighten the setscrew is 15-18 ozf.inch). The hub
set screw attaches the code wheel to the motor's shaft.
4. Use the center screwdriver slot, or either of the two side
slots, to rotate the encoder cap dot clockwise from the one
dot position to the two dot position. Do not rotate the
encoder cap counterclockwise beyond the one dot position.
The encoder is ready for use!
Encoder Mounting and Assembly
1. For HEDS-5500 and 5600: Mount encoder base plate onto
motor. Tighten screws. Go on to step 2.
1a. For HEDS-5540, 5640 and HEDM-5500, 5600: Slip
alignment tool onto motor shaft. With alignment tool in
place, mount encoder baseplate onto motor as shown above.
Tighten screws. Remove alignment tool.
2. Snap encoder body onto base plate locking all 4 snaps.
3c. Remove the hex wrench by pulling it straight out of the
encoder body.
11
Connectors
Manufacturer Part Number
AMP 103686-4
640442-5
Dupont/Berg 65039-032 with 4825X-000 term.
Avago HEDS-8902 (2 ch.) with 4-wire leads
(designed to mechanically lock into the
HEDS-5XXX, HEDM-5X0X Series) HEDS-8903 (3 ch.) with 5-wire leads
Molex 2695 series with 2759 series term.
Figure 5. HEDS-8902 and 8903 Connectors.
Typical Interfaces
HOST
PROCESSOR
HEDS–55XX
OR
HEDS-56XX
OR
HEDM-5X0X
HCTL-2016/
2020
QUADRATURE
DECODER/
COUNTER
CH. A
CH. B
HOST
PROCESSOR
CH. B
CH. A
HEDS–55XX
OR
HEDS-56XX
OR
HEDM-5X0X
HCTL-1100
MOTION
CONTROL IC
*
*
N/A*
12
Ordering Information
HEDS-5 Option
Shaft Diameter
01 - 2 mm 06 - 1/4 in.
02 - 3 mm 11 - 4 mm
03 - 1/8 in. 14 - 5 mm
04 - 5/32 in. 12 - 6 mm
05 - 3/16 in. 13 - 8 mm
Mounting Type
5 - Standard
6 - External
Mounting Ears
Through Hole
0 - None
5 - 8.9 mm (0.35 in.)
Outputs
0 - 2 Channel
4 - 3 Channel
Encoders with Metal Codewheels
HEDS-8910 0 Alignment Tool
(Included with each order of HEDS-554X/564X three channel encoders)
Shaft Diameter
01 - 2 mm 06 - 1/4 in.
02 - 3 mm 11 - 4 mm
03 - 1/8 in. 14 - 5 mm
04 - 5/32 in. 12 - 6 mm
05 - 3/16 in. 13 - 8 mm
Mounting Type
5 - Standard
6 - External
Mounting Ears
Resolution (Cycles/Rev)
B - 1000 CPR
J - 1024 CPR
Through Hole
0 - None
5 - 8.9 mm (0.35 in.)
Outputs
0 - 2 Channel
Encoders with Film Codewheels
HEDS-8910 0 Alignment Tool
(Included with each order of HEDM-550X/560X two channel encoders)
HEDM-5 0 Option
Resolution (Cycles/Rev)
(HEDS-550X, 560X 2 Channel)
S - 50 CPR F - 256 CPR
K - 96 CPR G - 360 CPR
C - 100 CPR H - 400 CPR
D - 192 CPR A - 500 CPR
E - 200 CPR I - 512 CPR
(HEDS-554X, 564X 3 Channel)
S - 50 CPR
K - 96 CPR
C - 100 CPR
E - 200 CPR
F - 256 CPR
G - 360 CPR
H - 400 CPR
A - 500 CPR
I - 512 CPR
13
01 02 03 04 05 06 11 12 13 14
HEDM-5500 B * * * ****
J* ****
HEDM-5505 B *
J***
HEDM-5600 B * *
J*
HEDM-5605 B *
J*
HEDS-5500 A * * * * * * ****
C**********
E*******
F** ***** *
G* ****
H****
I**********
K****
S*
HEDS-5505 A * * * *
C****
E***
F***
G**
H**
I***
K*
HEDS-5540 A * * * * * * ****
C*******
E**
F* * *
G*
H**
I*******
HEDS-5545 A * *
C*
H**
I*
HEDS-5600 A * * * *
C***
E*
G**
H**
I* *
01 02 03 40 05 06 11 12 13 14
HEDS-5605 A * *
C*
E*
F*
G*
H**
I*
HEDS-5640 A * * *
E*
F*
H*
HEDS-5645 A * * *
C*
E*
G*
H***
I*
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 Limited. All rights reserved. Obsoletes 5988-3996EN
5989-0885EN June 2, 2006
