HEDS-9000/9100
Two Channel Optical Incremental Encoder Modules
Data Sheet
Description
The HEDS-9000 and the HEDS-9100 series are high
performance, low cost, optical incremental encoder
modules. When used with a codewheel, these mod-
ules detect rotary position. The modules consist of a
lensed (LED) source and a detector IC enclosed in a small
C-shaped plastic package. Due to a highly collimated
light source and unique photodetector array, these mod-
ules are extremely tolerant to mounting misalignment.
The two channel digital outputs and the single 5 V sup-
ply input are accessed through five 0.025 inch square
pins located on 0.1 inch centers.
Standard resolutions for the HEDS-9000 are 500 CPR
and 1000 CPR for use with a HEDS-6100 codewheel or
equivalent.
For the HEDS-9100, standard resolutions between 96
CPR and 512 CPR are available for use with a HEDS-5120
codewheel or equivalent.
Features
•
High performance
•
High resolution
•
Low cost
•
Easy to mount
•
No signal adjustment required
•
Small size
•
-40°C to 100 °C operating temperature
•
Two channel quadrature output
•
TTL compatible
•
Single 5 V supply
Applications
The HEDS-9000 and 9100 provide sophisticated mo-
tion detection at a low cost, making them ideal for high
volume applications. Typical applications include print-
ers, plotters, tape drives, and factory automation equip-
ment.
Note: Avago Technologies encoders are not recommend-
ed for use in safety critical applications. Eg. ABS braking
systems, power steering, life support systems and critical
care medical equipment. Please contact sales represen-
tative if more clarification is needed.
ESD WARNING: NORMAL HANDLING PRECAUTIONS SHOULD BE TAKEN TO AVOID STATIC DISCHARGE.
Theory of Operation
The HEDS-9000 and 9100 are C-shaped emitter/detec-
tor modules. Coupled with a codewheel, they translate
the rotary motion of a shaft into a two-channel digital
output.
As seen in the block diagram, each 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 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 product the
digital waveforms.
The codewheel rotates between the emitter and detec-
tor, causing the light beam to be interrupted by the pat-
tern of spaces and bars on the codewheel. The photo-
diodes which detect these interruptions are arranged in
a pattern that corresponds to the radius and design of
the odewheel. 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 photo-
diode outputs are then fed through the signal process-
ing circuitry resulting in A, A, B, and B. Two comparators
receive these signals and produce the final outputs for
channels A and B. Due to this integrated phasing tech-
nique, the digital output of channel A is in quadrature
with that of channel B (90 degrees out of phase).
Package Dimensions
HEDS-9x00
GND
0.63 (0.025)
SQR. TYP.
OPTION CODE
5.1 (0.20)
26.67 (1.05)
15.2
(0.60)
2.54 (0.100) TYP.
1.0 (0.04)
DATE CODE
3.73 ± 0.05
(0.147 ± 0.002)
1.02 ± 0.10
(0.040 ± 0.004)
ALIGNING RECESS
2.44/2.41 DIA.
(0.096/0.095)
2.16 (0.085)
DEEP
HEDS-9X00
YYXX
X00
CL
17.27
(0.680)
20.96
(0.825)
20.8
(0.82)
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
1.78 ± 0.10*
(0.070 ± 0.004)
2.92 ± 0.10**
(0.115 ± 0.004)
10.16
(0.400)
TYPICAL DIMENSIONS IN MILLIMETERS AND (INCHES)
* GAP MEASUREMENT TO THE SURFACE WINDOW = 1.68
±
0.10 (0.066
±
0.004)
5.46 ± 0.10
(0.215 ± 0.004)
1.52 (0.060)
2.21
(0.087) 2.54
(0.100)
2.9
(0.11)
1.8
(0.07)
6.9 (0.27)
8.6 (0.34)
CH. B
V
CC
CH. A
N.C.
GND
5
4
3
2
1
V
CC
11.9
(0.47)
4.75 ± 0.10
(0.187 ± 0.004)
ALIGNING RECESS
2.44/2.41 X 2.79
(0.096/0.095 X 0.110)
2.16 (0.085) DEEP
OPTICAL
CENTER
45
5.8
(0.23)
8.81
(0.347)
1.85 (0.073)
8.64 (0.340)
REF.
ALIGNING RECESS
2.44/2.41 DIA.
(0.096/0.095)
2.16 (0.085) DEEP
4.11 (0.162)
6.35 (0.250) REF.
SIDE A
SIDE B
** HEIGHT TO THE WINDOW = 3.02
±
0.10 (0.119
±
0.004)
HEDS-9x01
V
CC
GND
0.63 (0.025)
SQR. TYP.
OPTION CODE
5.1 (0.20)
26.67 (1.05)
15.2
(0.60)
2.54 (0.100) TYP.
1.0 (0.04)
DATE CODE
3.73 ± 0.05
(0.147 ± 0.002)
16.76 ± 0.20
(0.66 ± 0.008)
4.01 ± 0.20
(0.158 ± 0.008)
8.6 (0.34)
CH. B
V
CC
CH. A
N.C.
GND
5
4
3
2
1
1.8
(0.07)
2.21
(0.087)
2.9
(0.11)
2.54
(0.100)
1.02 ± 0.10
(0.040 ± 0.004)
ALIGNING RECESS
2.44/2.41 DIA.
(0.096/0.095)
2.16 (0.085)
DEEP
1.85 (0.073)
8.64 (0.340)
REF.
2
HEDS-9X01
YYXX
X00
11.7
(0.46)
OPTICAL
CENTER LINE
CL
17.27
(0.680)
20.96
(0.825)
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
4.75 ± 0.10
(0.187 ± 0.004)
ALIGNING RECESS
2.44/2.41 X 2.79
(0.096/0.095 X 0.110)
2.16 (0.085) DEEP
OPTICAL
CENTER
45°
5.8
(0.23)
8.81
(0.347)
1.78 ± 0.10 *
(0.070 ± 0.004)
2.92 ± 0.10**
(0.115 ± 0.004)
10.16
(0.400)
5.46 ± 0.10
(0.215 ± 0.004)
ALIGNING RECESS
2.44/2.41 DIA.
(0.096/0.095)
2.16 (0.085) DEEP
4.11 (0.162)
6.35 (0.250) REF.
SIDE A
TYPICAL DIMENSIONS IN MILLIMETERS AND (INCHES)
* GAP MEASUREMENT TO THE SURFACE WINDOW = 1.68
±
0.10 (0.066
±
0.004)
** HEIGHT TO THE WINDOW = 3.02
±
0.10 (0.119
±
0.004)
SIDE B
Block Diagram
Output Waveforms
P
C
CHANNEL A
AMPLITUDE
ф
S1
S2
S3
S4
CHANNEL B
ROTATION
Definitions
Count (N):
The number of bar and window pairs or counts
per revolution (CPR) of the codewheel.
1 Shaft Rotation
1 cycle (C)
= 360 mechanical degrees,
= N cycles.
= 360 electrical degrees (°e),
= 1 bar and window pair.
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.
Direction of Rotation:
When the codewheel rotates in the
direction of the arrow on top of the module, channel A will
lead channel B. If the codewheel rotates in the opposite
direction, channel B will lead channel A.
Optical Radius (R
op
):
The distance from the codewheel’s
center of rotation to the optical center (O.C.) of the en-
coder module.
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.
3
Absolute Maximum Ratings
Storage Temperature, T
S
Operating Temperature, T
A
Supply Voltage, V
CC
Output Voltage, V
O
Output Current per Channel, I
out
-40°C to 100°C
-40°C to 100°C
-0.5 V to 7 V
-0.5 V to V
CC
-1.0 mA to 5 mA
Recommended Operating Conditions
Parameter
Temperature
Supply Voltage
Load Capacitance
Count Frequency
Symbol
T
V
CC
C
L
f
Min.
-40
4.5
Typ.
Max.
100
5.5
100
100
Units
°C
Volts
pF
kHz
Notes
Ripple < 100 mV
p-p
3.3 kΩ pull-up resistor
Velocity (rpm) x N
60
Note: The module performance is guaranteed to 100 kHz but can operate at higher frequencies.
Encoding Characteristics
Encoding Characteristics over Recommended Operating Range and Recommended Mounting Tolerances. These
Characteristics do not include codewheel/codestrip contribution.
Description
Pulse Width Error
Logic State Width Error
Phase Error
Sym.
∆P
∆S
∆φ
Typ.
30
30
2
Case 1 Max.
40
40
10
Case 2 Max.
Units
°e
°e
Notes
105
°e
Case 1: Module mounted on tolerance circle of ±0.13 mm (±0.005 in.).
Case 2: HEDS-9000 mounted on tolerances of ±0.50 mm (0.020”).
HEDS-9100 mounted ontolerances of ±0.38 mm (0.015”).
Electrical Characteristics
Electrical Characteristics over Recommended Operating Range, typical at 25°C.
Parameter
Supply Current
High Level Output Voltage
Low Level Output Voltage
Rise Time
Fall Time
Symbol
I
CC
V
OH
V
OL
t
r
t
f
Min.
2.4
Typical
17
Max.
40
0.4
Units
mA
Volts
Volts
ns
ns
Notes
I
OH
= -40 µA max.
I
OL
= 3.2 mA
C
L
= 25 pF
R
L
= 11 kΩ pull-up
200
50
4
Derating Curves over Extended Operating Frequencies (HEDS-9000/9100)
Below are the derating curves for state, duty, phase and V
OH
over extended operating frequencies of up to
240 kHz (recommended maximum frequency is 100 kHz). The curves were derived using standard TTL load.
–40°C operation is not feasible above 160 kHz because V
OH
will drop below 2.4 V (the minmum TTL for logic state high)
beyond that frequency.
0
CHANGE IN PULSE WIDTH ERROR
(ELECTRICAL DEGREE)
CHANGE IN STATE WIDTH ERROR
(ELECTRICAL DEGREE)
-10
-20
-30
-40
-50
120
140
160
200
180
FREQUENCY (kHz)
220
100
°
C
25
°
C
-40
°
C
240
50
40
30
20
10
0
120
140
160
200
180
FREQUENCY (kHz)
220
240
-40
°
C
25
°
C
100
°
C
0
CHANGE IN PHASE ERROR
(ELECTRICAL DEGREE)
CHANGE IN VOH (VOLTS)
5
4
3
2
1
0
120
140
160
180
200
FREQUENCY (kHz)
220
-40
°
C
240
100
°
C
25
°
C
-5
100
°
C
25
°
C
-10
120
140
160
180
200
FREQUENCY (kHz)
220
-40
°
C
240
5
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