AVAGO HEDS-9730-350 Small optical encoder modules 480lpi digital output Datasheet

HEDS-9730, HEDS-9731
Small Optical Encoder Modules 480lpi Digital Output
Data Sheet
Description
Features
The HEDS-973X is a high performance incremental
encoder module. When operated in conjunction with
either a codewheel or codestrip, this module detects
rotary or linear position. The encoder consists of a lensed
LED source and a detector IC enclosed in a small Cshaped plastic package. Due to a highly collimated light
source and a unique photodetector array, the module is
extremely tolerant to mounting misalignment.
• Small Size
The two channel digital outputs and 3.3V supply input
are accessed through four solder plated leads located on
2.54mm (0.1inch) centers.
• Wave Solderable
The standard HEDS-973X is designed for use with an appropriate optical radius codewheel or linear codestrip.
Other options are available. Please contact the factory for
more information.
Block Diagram
RESISTOR
VCC
3
LENS
PHOTODIODES COMPARATORS
A
+
LED
A B
+
B -
CHANNEL A
2
• High Resolution
• Two Channel Quadrature Output
• Linear and Rotary Applications
• No Signal Adjustment required
• TTL or 3.3V/5V CMOS Compatible
• Lead-free Package
• -40°C to 85°C Operating Temperature
• Single 3.3V Supply
Applications
The HEDS-973X provides sophisticated motion detection,
making closed loop control very cost competitive. Typical
applications include printers, plotters, copiers and office
automation equipment.
Note:
Avago Technologies’ encoders are not recommended for use in safety
critical applications, e.g., ABS braking systems and critical-care medical
equipment. Please contact a sales representative if more clarification is
needed.
CHANNEL B
4
SIGNAL
PROCESSING
CIRCUITRY
GND
1
EMITTER SECTION
CODE
WHEEL
DETECTOR SECTION
Figure 1
ESD WARNING: NORMAL HANDLING PRECAUTIONS SHOULD BE TAKEN TO AVOID STATIC DISCHARGE.
Theory of Operation
Definitions
A HEDS-973X is a C-shaped emitter/detector module.
Coupled with a codewheel, it translates rotary motion
into a two-channel digital output; coupled with a
codestrip, it translates linear motion into digital outputs.
Note: Refer to Figure 2
As seen in Figure 1, the module contains a single Light
Emitting Diode (LED) as its light source. The light is collimated into 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 photodetectors and a signal processing circuitry necessary to
produce the digital waveforms.
1 shaft Rotation = 360 degrees
The codewheel/codestrip moves between the emitter
and detector, causing the light beam to be interrupted
by the pattern of spaces and bars on the codewheel/
codestrip. The photodiodes, which detect these interruptions, are arranged in a pattern that corresponds to the
radius and count density of the codewheel/ codestrip.
These photodiodes are also spaced such that a light
period on one pair of detectors corresponds to a dark
period on the adjacent pairs of detectors. The photodiode
outputs are fed through the signal processing circuitry.
Two comparators receive these signal and produce the
final outputs for Channels A and B. Due to this integrated
phasing technique the output of channel A is in quadrature with Channel B (90 degrees out of phase).
Output Waveforms
C
AMPLITUDE
CHANNEL A
ф
S2
S3
S4
CHANNEL B
ROTATION
Figure 2.
2
= N cycles
1 cycle (c) = 360 electrical degree, equivalent to 1 bar and
window pair.
Pulse Width (P): The number of electrical degrees that an
output is high during one cycle, nominally 180°e or 1/2
a cycle.
Pulse Width Error (ΔP): 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 (ΔS): 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 on channel A and the center of
the high state on channel B. This value is nominally 90°e
for quadrature output.
Phase Error (Δφ): The deviation in electrical degrees of the
phase from its ideal value of 90°e.
P
S1
Count (N): The number of bar and window pairs or counts
per revolution (CPR) of the codewheel. Or the number of
lines per inch of the codestrip (LPI)
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.
Optical Radius (Rop): The distance from the codewheel’s
center of rotation to the optical center (O°C) of the
encoder module.
Angular Misalignment Error (EA): Angular misalignment of
the sensor in relation to then tangential direction. This
applies for both rotary and linear motion.
Mounting Position (RM): Distance from Motor Shaft center of
rotation to center of Alignment Tab receiving hole.
Absolute Maximum Ratings
Parameter
Symbol
Min.
Max.
Units
Storage Temperature
TS
-40
85
°C
Operating Temperature
TA
-40
85
°C
Supply Voltage
VCC
-0.5
7
Volts
Output Voltage
VO
-0.5
VCC
Volts
Output Current per Channel
IOUT
-1.5
19
mA
Soldering Temperature
TSOL
20
260
°C
Notes
t* 5 sec
Recommended Operating Conditions
Parameter
Symbol
Min.
Temperature
TA
-40
Supply Voltage
VCC
2.8
Load Capacitance
CL
Pull-up Resistor
RL
Frequency
f
Angular Misalignment
EA
Mounting Position
RM
Typ.
3.3 or 5
Max.
Units
85
°C
5.2
Volts
100
pF
Notes
Ripple < 100mVp-p
none
-2.0
Recommend no pullup. Device has integrated 2.5 kΩ on outputs
0.0
40
kHz
Velocity (rpm) x N/60
+2.0
Deg.
Refer to Mounting Consideration
ROP-0.14
(ROP -0.006)
Mm (inch) Refer to Mounting Consideration
Electrical Characteristics
Electrical Characteristics Over the Recommended Operating Conditions. Typical Values at 25°C.
Parameter
Symbol
Min.
Typ.
Max.
Units
Notes
Supply Current
ICC
12
25
40
mA
Typ. 3.3V
55
85
High Level
Output Voltage
VOH
Low Level
Output Voltage
VOL
2.4
0.4
Typ. 5V
Volts
When VOH = 2.4V (Min)Typ.
IOH = -0.4 mA @ 3.3VTyp.
IOH = -1.0 mA @ 5V
Volts
When VOL = 0.4V (Max)Typ.
IOL = 12 mA @ 3.3VTyp.
IOL = 14 mA @ 5V
CL=25 pF
Rise Time
tr
200
ns
Fall Time
tf
50
ns
Encoding Characteristics
Encoding Characteristics Over the Recommended Operating Conditions and Mounting Conditions These characteristics do not include codewheel/codestrip contribution. The typical values are average over the full rotation of the
codewheel
Parameter
Symbol
Typical
Maximum
Units
Pulse Width Error
ΔP
5
50
°e
State Width Error
ΔS
Δφ
3
50
°e
2
15
°e
Phase Error
3
Notes
Mounting Considerations
5.32 MAX.
(0.209)
4.40 ± 0.13
0.17 ± 0.005
CL OF ALIGNMENT TAB
SEE NOTE 1
Rm
6.30 MAX.
(0.248)
Rop
IMAGE SIDE OF
CODEWHEEL/CODESTRIP
6.50 MIN.
(0.256)
CENTER OF ROTATION
MOTOR SHAFT CENTER
-A-
2.03 MIN.
(0.080)
1.0 DEEP MIN.
(0.039)
EA
2X R
ALIGNMENT TAB RECEIVING HOLE
Rm = Rop - 0.14 (0.006)
2.03 HOLE MIN.
(0.080)
1.0 DEEP MIN.
(0.039)
DIMENSIONS IN MILLIMETERS (INCHES).
A 0.13 mm (0.005")
Note: These dimensions include shaft end play and codewheel warp.
For both rotary and linear motion, angular misalignment, EA must be * ± 1 degrees to achieve Encoding Characteristics.
All dimension for mounting the module and codewheel/codestrip should be measured with respect to two mounting posts, as shown above
Recommended Codewheel and Codestrip Characteristics
MAX 3.4 (0.134)
Wb
Ww
Lw
Rc
Rop
L
W1
W2
Ww
4
Wb
Parameter
Symbol
Min.
Max.
Window/bar Ratio
Ww/Wb
0.9
1.1
Window Length (Rotary)
LW
1.80
(0.071)
2.31
(0.091)
mm
(inch)
Absolute Maximum Codewheel Radius (Rotary)
Rc
Rop + 3.40
(Rop + 0.134)
mm
(inch)
Center of Post to Inside Edge of Window
W1
1.04
(0.041)
mm
(inch)
Center of Post to Outside Edge of Window
W2
0.76
(0.036)
mm
(inch)
Center of Post to Inside Edge of Codestrip
L
3.60
(0.142)
Unit
mm
(inch)
Notes
Includes eccentricity errors
Ordering Information
HEDS - 973
Option
Resolution
3 - 480 LPI
Lead Configurations
0 - Straight leads
1 - Bent leads
Bracket Option
50
Package Dimension
Option 50
LEAD THICKNESS = 0.25 mm
LEAD PITCH = 2.54 mm
3.8
5.5 ± 0.3
1.4
0.8
1.70 ± 0.15
4.2
3.90 ± 0.10
7.5
10.1
PART #
(REFER -05)
GND
50
7.0
12.6 ± 0.5
YYWW
3.9
X
4.2
C
5.0
2x ∅ 2.00 ± 0.02
PIN 1 ID
AVAGO
6.4
0.14
(OPTICAL CENTER)
CH A
OPTION CODE
XXXXX
8.7
3.0
R 2.6
V CC
R 1.4
CH B
10.8 ± 0.5
0.5
8.4
DATE CODE
15.0
C = COUNTRY
OF ORIGIN
MARKING
(REFER -05
FOR DETAILS)
20.2 ± 0.5
1.8
9.8
Bent Version - Option 50
LEAD THICKNESS = 0.25 mm
LEAD PITCH = 2.54 mm
6.0
4.2
3.9
0.14
(OPTICAL CENTER)
0.8
2x ∅ 2.00 ± 0.02
1.70 ± 0.15
4.2
PART #
(REFER -05)
3.90 ± 0.10
7.5
10.1
GND
50
V CC
AVAGO
9.8
0.5
10.8 ± 0.5
PIN 1 ID
7.0
12.6 ± 0.5
8.4
15.0
20.2 ± 0.5
1.8
3.8
5
CH A
9.2 ± 0.3
X
5.0
OPTION CODE
YYWW
1.4
6.4
5° TYP.
C
8.7
R 1.4
XXXXX
R 2.6
CH B
3.0 ± 0.3
DATE CODE
C = COUNTRY
OF ORIGIN
MARKING
(REFER -05
FOR DETAILS)
Wave Soldering Profile
Y-AXIS
7 sec MAX.
260°C
FLOW
COOL
DOWN
120° C/20 sec MAX.
X-AXIS
Parameter
Min.
Max.
Nominal values
Units
A
Solder Pot Temperature
NA
260
250 - 260
°C
B
Preheat Zone Temperature
85
120
100 - 120
°C
C
Dip in Time
5
7
5
sec
D
Solder Pot Zone (PCB Top)
NA
NA
NA
°C
E
Solder Pot Zone (Encoder Lead)
200
NA
≥ 200
°C
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 © 2005-2009 Avago Technologies. All rights reserved. Obsoletes 5989-0837EN
AV02-1057EN - January 5, 2010
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