HEDR-54xx Series
Mid-Sized Housed Encoder
Data Sheet
Description
Features
The HEDR-542x series are high performance, cost-effective, two-channel optional incremental housed encoders.
These encoders emphasize high reliability, high resolution,
and easy assembly. The HEDR-542x housed encoders use
reflective technology to sense rotary position. This sensor
consists of an LED light source and a photodetector IC in
a single SO-8 surface mount package. The outputs of the
HEDR-542x encoders are two square waves in quadrature.
These encoders may be quickly and easily mounted to a
motor.
Two channel quadrature output
Quick and easy assembly
Cost-effective
Ideal for small motor systems
-10° C to +85 °C operating temperature
Right angle connector available
Hub available in either a set screw configuration or a
press-fit/adhesive mount configuration
External mounting ears available
Applications
The HEDR-542x provides motion detection at a low cost,
making them ideal for high volume applications. Typical
applications include vending machines and motor manufacturing applications.
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.
Available Styles
Right angle version (shown here with press
fit/adhesive mount hub option)
External mounting ears version (shown here
with set screw type hub)
ESD WARNING: Normal Handling Precautions should be taken to avoid static discharge.
Package Dimensions
B
+5
A
GND
DETAIL A
DETAIL A
14.4
11.7 13.9
B +5 V A
NC GND
1.5
Ø23.0
B +5
A
GND
DETAIL B
DETAIL B
11.7 13.9
GND NC
A +5 V B
1.5
Ø23.0
15.2
17.4 17.9
5.0
Ø23.0
Ø23.0
8.5
15.2
17.9
5.0
46.0
52.0
2
2.0
NOTE: TYPICAL DIMENSIONS IN MILLIMETERS
Theory of Operation
The HEDR-542X translates rotary motion of a shaft into a
two channel digital output. As seen in the block diagram,
the HEDR-542X series has three key parts: a single Light
Emitting Diode (LED) light source, a photodetector IC
with a set of uniquely configured photodiodes, and a pair
of lenses. The lens over the LED focuses light onto the
codewheel. Light is either reflected or not reflected back
to the lens over the photodetector IC. As the codewheel
rotates an alternating pattern of light and dark corresponding to the pattern of the codewheel falls upon the
photodiodes. This light is used to produce internal signals
A and A', and B and B'. As part of this "push-pull" detector
system, these signals are fed through comparators that
are part of the signal processing circuitry to produce the
final outputs for channels A and B.
V LED
R
CODEWHEEL
GND
V CC
CH A
CH B
SIGNAL
PROCESSING
CIRCUITRY
GND
Definitions
Count (N): For rotary motion, the number of bar and window
Pulse Width Error (P): The deviation in electrical degrees of
pairs or Counts Per Revolution (CPR) of the codewheel. For
linear motion, the number of bar and window pairs per
unit length (Lines Per Inch [LPI] or Lines Per mm [LPmm]).
the pulse width from its ideal value of 180°e.
One Cycle (C): 360 electrical degree (°e), 1 bar and window
pair.
State Width (S): The number of the electrical degrees
between a transition in the output of the channel B. There
are 4 states per cycle, each nominally 90°e.
State Width Error (S): The deviation in electrical degrees of
One Shaft Rotation: 360 mechanical degrees, N cycles
(rotary motion only).
each state width from its ideal value of 90°e.
Phase (): The number of electrical degrees between the
Line Density: The number of reflective and non-reflective
pairs per unit length, expressed as either Lines Per Inch
(LPI) or Lines Per mm (LPmm).
Pulse Width (P): The number of electrical degrees that an
center of the high state on the channel A and the center
of the high state of channel B. This value is nominally 90°e.
Phase Error (): The deviation in electrical degrees of the
phase from its ideal value of 90°e.
output is high during one cycle, nominally 180°e or 1/2
a cycle.
Output Waveforms
Direction of Motor Rotation
CH. I
C
ALL FOUR STATES (S1 TO S4)
ARE MAINTAINED
AMPLITUDE
P
CH. A
S1
S2
S3
S4
Ø
CH. B
CODEWHEEL ROTATION
3
When the codewheel rotates in the
clockwise direction (as viewed from the
encoder end of the motor), channel A will
lead channel B. If the codewheel rotates in
the counterclockwise direction, channel B
will lead channel A.
Absolute Maximum Ratings
Storage Temperature
-40° C to +85° C
Operating Temperature
-10°-C to +85°-C
Supply Voltage
-0.5 V to 7 V
Output Voltage
-0.5 V to VCC
Output Current per Channel
-2.0 mA to 12 mA
Shaft Axial Play
± 0.25 mm
Shaft Eccentricity Plus Radial Play
0.04 mm
Radial Play between Housing and Cover
0.2 mm – 0.5 mm
Distance between Tip of Codewheel Shaft and PC Board
0.4 mm – 0.5 mm
Distance between Codewheel and Stopper before Reset
0.25 mm – 0.35 mm
Distance between Codewheel and Stopper after Reset
0.75 mm
Concentricity Misalignment between Mounted Base
0.12 mm
Plate Center Bore and Motor Shaft
Frequency
16 kHz
Recommended Operating Conditions
Parameter
Symbol
Min.
Temperature
TA
0
Typical
Max.
Units
85
°C
Notes
Supply Voltage
VCC
4.5
5.0
5.5
Volts
LED Current
ILED
13
15
18
mA
Ripple < 100 mVp–p
Load Capacitance
CL
100
pF
2.7 K Pull-Up
Typical
Max.
Units
Notes
18
33
mA
Electrical Characteristics
(Over recommended operating conditions. Typically at 25° C)
Parameter
Symbol
Supply Current
ICC
High Level Output Voltage
VOH
Low Level Output Voltage
VOL
Min.
2.4
0.4
Encoding Characteristics
Parameter
Symbol
Typical
Max.
Units
Pulse Width Error
P
7
75
°e
State Width Error
S
15
60
°e
Phase Error
15
60
°e
Position Error
50
120
arcmin
Cycle Error
C
10
45
°e
4
V
IOH = –2 mA min.
V
IOL = 12 mA max.
Mechanical Characteristics
Parameter
Dimension
Tolerance
Units
Codewheel Fits these Standard Shaft Diameters
Press Fit/Adhesive Mount Hub
Set Screw Hub
2, 3, 4
2, 3, 4, 5, (1/8)
+0/–0.01
(+0/–0.0005)
mm
(in.)
Allowable Motor Shaft Length
Press Fit/Adhesive Mount Hub
Set Screw Hub (uses size M1.5 Allen wrench, not included)
Between 7.5 and 8.0
Between 7.5 and 11.5
mm
Bolt Circle Diameter (2 holes)
16 to 18
mm
Mounting Screw Size
M2
M2.5, (2-56) for external
mounting ears
mm
(in.)
Electrical Interface
Pins configuration HEDR-542x series
Pull up resistors on output pins 2, 3, and 5 have already
been integrated into the mid-sized encoder. Each of the
three encoder outputs can drive a single TTL load in this
configuration.
Pin 1
GND
Pin 2
NC
Pin 3
Ch.A
Pin 4
5V
Connectors
Pin 5
Ch.B
The connector to be used with the mid-sized encoder
is Molex Part Number 51021-0500. This is a 5 connector
crimp wire to board connector.
The connector used on the encoder is orientation proof
type, 2 different cables configuration required for connection to right angle and axial angle type encoder.
5
Standard Mounting
Mounting Considerations
The mid-sized encoder must be aligned using the optional aligning pins, as specified in Figure 1, by using the optional
motor boss shown in Figure 2, or by using an alignment tool or as shown in Encoder Mounting and Assembly.
OPTIONAL ALIGNMENT PINS DIAMETER 1.940/2.007. 2 PLACES
ON 14.50 DIAMETER CIRCLE.
MAX HEIGHT 1.9
OPTIONAL MOTOR BOSS DIAMETER 9.96/10.01
MAX HEIGHT 1.5
SHAFT LENGTH
M2 2 PLACES EQUALLY SPACED
ON BOLT CIRCLE BETWEEN
16 AND 20
Figure 1.
Mounting with External Ears
OPTIONAL ALIGNMENT PINSDIAMETER 1.940/2.007. 2 PLACES
ON 14.50 DIAMETER CIRCLE.
MAX HEIGHT 1.9
M2 2 PLACES EQUALLY SPACED
ON DIAMETER 46 BOLT CIRCLE
Figure 2.
6
OPTIONAL MOTOR BOSS - DIAMETER 9.96/10.01
MAX HEIGHT 1.5
SHAFT LENGTH
Encoder Mounting and Assembly
Press Fit Style Encoder
BASE PLATE
1. If not using optional alignment pins or motor boss to
locate the base plate, slip alignment tool onto motor
shaft. Slip encoder base plate into place on motor
as shown below. Tighten screws or attach with an
adhesive. If using alignment tool, remove it.
ALIGNMENT TOOL
MOTOR
2. Place the hub in the housing assembly on top of the
motor shaft. Lining up the guide (connector side) at
the bottom of the housing with the slot (indicator side)
on the encoder base plate, the housing latches should
be aligned to the respective baseplate catches now.
Press the housing assembly downward and slide the
hub into and along the shaft, until the 3 latches make
contact with the catches.
MOTOR SHAFT
LATCH
(3 POSITION)
GUIDE
(CONNECTOR SIDE)
CATCH
(3 POSITION)
INDICATOR
SLOT (INDICATOR SIDE)
30.0°
60.0°
INDICATOR
NOTE:
THIS IS A TOP VIEW OF THE BASE PLATE.
INDICATOR IS ALSO INDICATING THE
CONNECTOR DIRECTION. ANGULAR OFFSET
TO OPTIONAL ALIGNMENT PIN IS 60°.
TOLERANCE FOR THE ANGLE IS ± 2°.
7
3. Press down the housing assembly until it snaps into
place. Recommended force is 3.5 kgf minimum, 4.0 kgf
nominal, and 4.5 kgf maximum. Note that the encoder
is shipped such that the housing assembly and the
base plate are not being snapped together.
8
4. Using the end of a pen or other appropriate tool,
press the triangular portion of the housing assembly
downward. Recommended force is between 3.5 kgf
to 4.0 kgf. This will set the codewheel and hub into
their proper position through the internalguide of the
triangular piece. When the triangular piece is released,
it should naturally spring back to its original position,
eliminating contact between the housing assembly
and the codewheel. The encoder is now ready for use.
Set Screw Style Encoder
ALIGNMENT TOOL
1. If not using optional alignment pins or motor boss to
locate the base plate, slip alignment tool onto motor
shaft. Slip encoder base plate into place on motor
as shown below. Tighten screws or attach with an
adhesive. If using alignment tool, remove it.
BASE PLATE
MOTOR
2. Slip the set screw hub into the shaft. Proper finger-wear must be worn to avoid contamination on codewheel surface
(top of hub). Place an Allen wrench into the socket of the set screw while aligning it on the Allen wrench groove.
Lining up the guide (connector side) at the bottom of the housing with the slot (indicator side) on the encoder
baseplate, the housing latches should be aligned to the respective baseplate catches. Move the housing assembly
downward until the 3 latches make contact with the catches.
HOUSING ASSEMBLY
MOTOR SHAFT
GUIDE
(CONNECTOR
SIDE)
SET SCREW HUB
ALLEN
WRENCH
SLOT
(INDICATOR SIDE)
9
ALLEN WRENCH GROOVE
3. Press down the housing assembly, holding the set
screw and Allen wrench in their initial position until
the housing assembly snaps into place. Recommended
force is 3.5 kgf minimum, 4.0 kgf nominal, and 4.5 kgf
maximum.
ALLEN WRENCH
MOTOR
4. Using the end of a pen or other appropriate tool,
press the triangular portion of the housing assembly
downward. Recommended force is between 3.5 kgf
to 4.0 kgf. Then apply a downward force on the end
of the Allen wrench. This sets the codewheel position
by levering the codewheel upward against internal
guide of the triangular piece. While continuing to
apply a downward force on both tools, rotate the Allen
wrench in the clockwise direction until the hub set
screw is tightened against the motor shaft. Remove the
Allen wrench by pulling it straight out of the housing
assembly. When the triangular piece is released, it
should naturally spring back to its original position,
eliminating contact between the housing assembly
and the codewheel. The encoder is now ready for use.
10
Ordering Information
*HEDR-5 4 X X – X X X X X
Shaft
Output
Connector
01 = 2 mm
02 = 3 mm
03 = 1/8 inch
11 = 4 mm
14 = 5 mm
0 = standard/axial
1 = right angle/radial
Hub
2 = 2 channel
S2 = Set screw with mounting ears base plate
P1 = Pressfit without mounting ears base plate
Resolution
E = 200 CPR
*Note: Part numbers currently available:
a. HEDR-5420-ES201
b. HEDR-5420-ES202
c. HEDR-5420-ES203
d. HEDR-5420-ES211
e. HEDR-5420-ES214
f. HEDR-5421-EP111
Ordering Information for Alignment Tool
HEDR-5900-000
Shaft
01 = 2 mm
02 = 3 mm
03 = 1/8"
11 = 4 mm
14 = 5 mm
For product information and a complete list of distributors, please go to our web site: www.avagotech.com
Avago, Avago Technologies, and the A logo are trademarks of Avago Technologies in the United States and other countries.
Data subject to change. Copyright © 2005-2012 Avago Technologies. All rights reserved. Obsoletes 5988-9450EN
AV02-3576EN - August 7, 2012