AGILENT HEDT-9140

High Temperature 140 °C
Three Channel Optical
Incremental Encoder Modules
Technical Data
HEDT-9040
HEDT-9140
Features
Description
• -40°C to 140°C Operating
Temperature
• Two Channel Quadrature
Output with Index Pulse
• Suitable for Automotive
Applications
• Resolution up to 1024
Counts per Revolution
• Low Cost
• Easy to Mount
• No Signal Adjustment
Required
• Small Size
The HEDT-9040 and HEDT-9140
are high temperature three
channel optical incremental
encoder modules. When used with
a codewheel, these low cost
modules detect rotary position.
Each module consists of a lensed
LED source and a detector IC
enclosed in a small plastic
package. Due to a highly
collimated light source and a
unique photodetector array, these
modules provide the same high
performance found in the HEDS9040/9140 three channel
encoders.
Package Dimensions
5.1 (0.20)
DATE CODE
3.73 ± 0.05
(0.147 ± 0.002)
HEDS-9X40
YYWW
ALIGNING RECESS
2.44/2.41 DIA.
1.85 (0.073)
(0.096/0.095)
2.16 (0.085)
8.64 (0.340)
DEEP
REF.
X00
1.02 ± 0.10
(0.040 ± 0.004)
CL
17.27
(0.680)
20.96
(0.825)
SIDE A
2.21
(0.087) 2.54
(0.100)
20.8
(0.82)
2.9
(0.11)
6.9 (0.27)
11.9
(0.47)
11.7
(0.46)
2.67 (0.105) DIA.
MOUNTING THRU
HOLE 2 PLACES
2.44/2.41 X 2.79
(0.096/0.095 X 0.110)
2.16 (0.085) DEEP
OPTICAL CENTER
OPTICAL
CENTER LINE
5.46 ± 0.10
(0.215 ± 0.004)
1.78 ± 0.10
(0.070 ± 0.004)
2.92 ± 0.10
(0.115 ± 0.004)
8.81
5.8
45° (0.23) (0.347)
4.75 ± 0.01
(0.187 ± 0.004)
OPTICAL
CENTER
4.11 (0.162)
10.16
(0.400)
TYPICAL DIMENSIONS IN
MILLIMETERS AND (INCHES)
GND
1.8
(0.07)
1.52 (0.060)
1.0 (0.04)
CH. B
VCC
CH. A
CH. 1
GND
2.54 (0.100) TYP.
OPTION CODE
VCC
8.6 (0.34)
5
4
3
2
1
0.63 (0.025)
SQR. TYP.
26.67 (1.05)
15.2
(0.60)
6.35 (0.250) REF.
SIDE B
ESD WARNING: NORMAL HANDLING PRECAUTIONS SHOULD BE TAKEN TO AVOID STATIC
DISCHARGE.
2
The HEDT-9040 and 9140 have
two channel quadrature outputs
plus a third channel index output.
This index output is a 90
electrical degree high true index
pulse.
Block Diagram
The HEDT-9040 is designed for
codewheels which have an optical
radius of 23.36 mm (0.920 in.).
The HEDT-9140 is designed for
codewheels which have an optical
radius of 11.00 mm (0.433 in.).
The quadrature signals and the
index pulse are accessed through
five 0.025 inch square pins
located on 0.1 inch centers.
Resolutions between 360 and
1024 counts per revolution are
available. Consult local Agilent
sales representatives for other
resolutions.
Applications
The HEDT-9040 and 9140
provide high temperature motion
control detection at a low cost,
making them suitable for automotive and industrial applications.
Note: Agilent 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.
Theory of Operation
The HEDT-9040 and 9104 are
emitter/detector modules.
Coupled with a codewheel, these
modules translate the rotary
motion of a shaft into a threechannel digital output.
As seen in the block diagram, the
module contains a single Light
Emitting Diode (LED) as its light
source. The light is collimated
into a parallel beam by means of a
single 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 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 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 output of the comparator for
I and I is sent to the index
processing circuitry along with
the outputs of channels A and B.
The final output of channel I is an
index pulse Po which is a one
state width (nominally 90
electrical degrees), high true
index pulse. This pulse is
coincident with the low states of
channels A and B.
3
Output Waveforms
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.
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 difference between an observed shaft
angle which gives rise to one
electrical cycle, and the nominal
angular increment of l/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 (∆ P): The
deviation, in electrical degrees, of
the pulse width from its ideal
value of 180°e.
Absolute Maximum Ratings
Storage Temperature, TS ................................................. -40°C to 140°C
Operating Temperature, TA ............................................. -40°C to 140°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 5 mA
Shaft Axial Play ................................................. ± 0.25 mm (± 0.010 in.)
Shaft Eccentricity Plus Radial Play ..................... 0.1 mm (0 004 in.) TIR
Velocity ........................................................................... 30,000 RPM[1]
Acceleration ............................................................. 250,000 rad/sec2[1]
Note:
1. Absolute maximums for HEDS-5140 codewheel only.
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.
Direction of Rotation: When the
codewheel rotates in the direction
of the arrow on top of the
module, channel A will load
channel B. If the codewheel
rotates in the opposite direction,
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 during one full
shaft rotation. This value is
nominally 90°e or 1/4 cycle.
4
Recommended Operating Conditions
Parameter
Symbol
Min.
Max.
Units
TA
-40
140
°C
Supply Voltage
VCC
4.5
5.5
Volts
Load Capacitance
CL
100
pF
2.7 kΩ pull-up
Count Frequency
f
50
kHz
Velocity (rpm) x N/60
Shaft Perpendicularity
Plus Axial Play
± 0.25
(± 0.010)
mm
(in.)
6.9 mm (0.27 in.) from
mounting surface
Shaft Eccentricity Plus
Radial Play
0.04
(0.0015)
mm (in.)
TIR
6.9 mm (0.27 in.) from
mounting surface
Temperature
Typ.
5.0
Notes
Ripple < 100 mVp-p
Note: The module performance is guaranteed to 50 kHz but can operate at higher frequencies.
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 of HEDS-514X and HEDS6145 codewheels.
Parameter
Symbol
Min.
Typ.*
Max.
Units
Cycle Error
∆C
5
10
°e
Pulse Width Error
∆P
7
30
°e
Logic State Width Error
∆S
5
30
°e
Phase Error
∆φ
2
15
°e
Position Error
∆Θ
10
40
min. of arc
Index Pulse Width
PO
60
90
120
°e
CH. I rise after CH. B or CH. A fall
t1
20
430
1490
ns
CH. I fall after CH. A or CH. B rise
t2
40
250
620
ns
Note: Module mounted on tolerance circle of ± 0.13 mm (± 0.005 in.) radius referenced from module Side A aligning recess centers. 2.7
kΩ pull-up resistors used on all encoder module outputs.
Electrical Characteristics
Electrical Characteristics over Recommended Operating Range.
Parameter
Symbol
Min.
Typ.*
Max.
Units
Supply Current
ICC
30
57
85
mA
High Level Output Voltage
VOH
2.4
Low Level Output Voltage
VOL
0.4
V
IOH = -100 µA min.
V
IOL = 3.86 mA max.
CL = 25 pF
RL = 2.7 kΩ pull-up
Rise Time
tr
90
ns
Fall Time
tf
80
ns
*Typical values specified at VCC = 5.0 V and 25°C.
Notes
5
Mechanical Characteristics
Part No.
Parameter
HEDS-5140
11.00 mm optical
radius codewheel
Codewheel Available
to Fit These Standard
Shaft Diameters
Dimension
Units
4
8
+0.000
-0.015
mm
1/8
1/4
+0.000
-0.0007
in.
2 3
5 6
5/32
3/16
Moment of Inertia
Tolerance
0.6 (8.0 x 10-6 )
g-cm2 (oz-in-s2)
Note: The tolerance requirements are on the mating shaft, not on the codewheel.
Electrical Interface
To insure reliable encoding
performance, the HEDT-9040 and
9140 three channel encoder
modules 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 in
close proximity of the encoder
module (within 4 feet). Each of
the three encoder module outputs
can drive a single TTL load in this
configuration.
Figure 1. Pull-up Resistors on HEDT-9X40 Encoder Module Outputs.
Mounting Considerations
Figure 2 shows a mounting
tolerance requirement for proper
operation of the HEDT-9040 and
HEDT-9140. The Aligning Recess
Centers must be located within a
tolerance circle of 0.13 mm
(0.005 in.) radius from the
nominal locations. This tolerance
must be maintained whether the
module is mounted with Side A as
the mounting plane using aligning
pins (see Figure 5), or mounted
with Side B as the mounting plane
using an alignment tool (see
Figures 3 and 4).
Figure 2. HEDT-9X40 Mounting Tolerance.
6
Mounting the HEDT-9140
with an Alignment Tool
The HEDS-8905 alignment tool is
recommended for mounting the
HEDT-9140 module with Side B
as the mounting plane. This tool
can only be used when the HEDT9140 module is mounted with the
HEDS-5140 (codewheel with
hub). The HEDS-8905 tool fixes
the module position using the
codewheel hub as a reference. It
will not work if Side A is used as
the mounting plane.
The following assembly procedure
uses the HEDS-8905 alignment
tool to mount an HEDT-9140
module and an HEDS-5140
codewheel:
Instructions:
1. Place codewheel on shaft.
2. Set codewheel height: (a) place
alignment tool on motor base
(pins facing up) flush up against
the motor shaft as shown in
Figure 3. (b) Push codewheel
down against alignment tool. The
codewheel is now at the proper
height. (c) Tighten codewheel
setscrew and remove alignment
tool.
Some motors have a boss around
the shaft that extends above the
mounting plane. In this case, the
alignment tool cannot be used as
a gage block to set the codewheel
height as described in 2(a), (b),
and (c). If boss is above
mounting plane: Slide module
onto motor base, adjusting height
of codewheel so that it sits
approximately in the middle of
module slot. Lightly tighten setscrew. The codewheel height will
be more precisely set in step 5.
3. Insert mounting screws
through module and thread into
the motor base. Do not tighten
screws.
Figure 3. Alignment Tool is Used to Set Height of
Codewheel.
4. Slide alignment tool over
codewheel hub and onto module
as shown in Figure 4. The pins of
the alignment tool should fit
snugly inside the alignment
recesses of the module.
If boss is above mounting plane:
The pins of the tool may not mate
properly because the codewheel is
too high on the shaft. Loosen
codewheel setscrew and lower
codewheel slightly. Retighten
setscrew lightly and attempt this
step again.
5. While holding alignment tool in
place, tighten screws down to
secure module.
If boss is above mounting plane:
Push codewheel up flush against
alignment tool to set codewheel
height. Tighten codewheel
setscrew.
6. Remove alignment tool.
Figure 4. Alignment Tool is Placed over Shaft and onto
Codewheel Hub. Alignment Tool Pins Mate with Aligning
Recesses on Module.
7
Mounting with Aligning Pins
The HEDT-9040 and HEDT-9140
can also be mounted using
aligning pins on the mounting
surface.
(Agilent does not provide aligning
pins.) For this configuration,
Side A must be used as the
mounting plane. The aligning
recess centers must be located
within the 0.13 mm (0.005 in.)
Figure 5. Mounting Plane Side A.
Figure 6. HEDS-5140 Codewheel Used with HEDT-9140.
Radius Tolerance Circle as
explained in “Mounting
Considerations.” Figure 5 shows
the necessary dimensions.
8
Ordering Information
Three Channel Encoder Modules and Codewheels, 11.00 mm Optical Radius
HEDT-914
Option
0 0
HEDS-514
Option
Hub
0 - Codewheel w/Hub
5 - Codewheel w/o Hub
LEAD
Resolution
(Cycles/Rev)
0-STRAIGHT LEADS
1-BENT LEADS
A
E
F
G
I
*
HEDT-9141
*
01
I
00-WITHOUT HUB
01 - 2 mm
11 - 4 mm
02 - 3 mm
14 - 5 mm
03 - 1/8 in.
12 - 6 mm
04 - 5/32 in. 13 - 8 mm
06 - 1/4 in.
1 = 512 CPR
HEDT-9140
HEDS-5140
Shaft Diameter
02
*
03
04
*
Accessories
HEDS-8905
Alignment Tool for mounting the HEDT-9140.
05
06
*
08
09
10
11
12
13
14
*
*
*
*
9
Using Multiple Index
Pulses
The third channel index (Channel
I) is not limited to occurring just
once per revolution. Index pulses
may be placed arbitrarily over a
full codewheel rotation. This is
done by altering only the pattern
of the codewheel with no
modifications necessary to the
HEDT-9X40 module. The only
restriction is that, depending on
the CPR of the codewheel,
consecutive index pulses may
have to be separated by at least
10 full cycles.
Multiple index pulses can provide
more precise absolute position
information. By strategically
placing the index pulses, a unique
index series can be created for a
particular angular position. This
leads to the idea of the “quasiabsolute” encoder in which only a
partial turning of the codewheel is
required to determine the
absolute position.
A special codewheel is required to
accomplish a multiple index
pattern. The standard HEDS5140, 5145, and 6145 codewheels have one index pulse per
full revolution. Please consult a
local Agilent sales representative
for further information.
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
(408) 654-8675
Europe: +49 (0) 6441 92460
China: 10800 650 0017
Hong Kong: (+65) 271 2451
India, Australia, New Zealand: (+65) 271 2394
Japan: (+81 3) 3335-8152(Domestic/International), or 0120-61-1280(Domestic Only)
Korea: (+65) 271 2194
Malaysia, Singapore: (+65) 271 2054
Taiwan: (+65) 271 2654
Data subject to change.
Copyright © 2002 Agilent Technologies, Inc.
Obsoletes 5965-5886E
February 26, 2002
5988-5281EN