HEDS-9721#P53 Avago Technologies US Inc., HEDS-9721#P53 Datasheet - Page 2

• Manufacturer Part Number: HEDS-9721#P53
• Description: Encoders 2 Channel 150CPR
• Manufacturer: Avago Technologies US Inc.
• Type: Optical Encoderr

Specifications of HEDS-9721#P53

• Number Of Channels: 2
• Mounting Style: PCB
• Supply Voltage: 5 V
• Product: Optical
• Technology: Linear
• Termination Style: Solder Pin
• Detents: No
• Motion: Linear
• Index Output: Not Indexed
• Encoder Signal: Digital
• Built In Switch: No
• Shaft Style: Not Required
• Shaft Diameter (mm): Not Requiredmm
• Operating Supply Voltage (typ): 5VDC
• Operating Temperature Min Deg. C: -40C
• Operating Temperature Max Deg. C: 85C
• Terminal Type: PC Pins
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Applications
The HEDS-9700 provides sophisticated motion detection
at a low cost, making closed-loop control very cost-com-
petitive! Typical applications include printers, plotters,
copiers, and office automation equipment.
Note: Avago Technologies encoders are not recom-
mended 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.
Block Diagram
2
EMITTER SECTION
LED
RESISTOR
LENS
WHEEL
CODE
PHOTO-
DIODES
PROCESSING
CIRCUITRY
SIGNAL
DETECTOR SECTION
COMPARATORS
A
A
B
B
+
+
-
-
CHANNEL A
CHANNEL B
V CC
GND
3
2
4
1
Theory of Operation
The HEDS-9700 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 a 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 codewheel/codestrip moves between the emitter
and detector, causing the light beam to be interrupted
by the pattern of spaces and bars on the code wheel/
codestrip. The photodiodes which detect these interrup-
tions are arranged in a pattern that corresponds to the
radius and count density of the codewheel/codestrip.
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 fed through the signal processing circuitry. Two
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 channel B (90 degrees out of phase).