Broadcom AS22 Series Installation and operating instructions

Application Note
Broadcom AS-22-Kit-Encoder-AN101
December 15, 2017
Introduction
The Broadcom® AS22 Series kit encoder solution offers a
compact size with an overall diameter of 22 mm and height
of 10.9 mm for the space-constrained application.
To meet the growing demand for high-precision application,
the AS22 Series offers a wide range of incremental
resolution, ranging from 360 to 2048 counts per revolution
(cpr).
The encoder provides A and B channel of incremental digital
signal output, as well as a digital index pulse per revolution
enabling the homing positioning operation. The
three-channel solution comes with the optional RS 422
compatible differential output offering the high transmission
noise immunity for signal over cable.
To cater to a wide selection of industrial applications, this
encoder is design to operate in a robust environment with
the operating temperature ranging from –20°C to +100°C.
The AS22 Series is designed for ease of use. The kit
solution is engineered with the hassle-free installation,
eliminating the need for a tedious alignment process.
This application note provides step-by-step mounting
instructions on how to install the AS22 series encoder onto
a motor.
Encoder Mounting and Assembly
Instruction
Step 1: Base Plate Centering
Place the base plate over the motor shaft, and make sure it
sits flat on the mounting surface. Slide the alignment sleeve
to the motor shaft with the taper surface facing the base
plate. Ensure the alignment sleeve is aligned to the hole on
the base plate. Align the two holes on the base plate to the
screw holes on mounting surface. Slightly pressing the
alignment sleeve, and tighten the 2x M2.5 screw with
0.10 Nm to 0.23 Nm (0.9 in.lb to 2.0 in.lb) to secure the
base plate. It is recommended that you apply adhesive to
the screw-baseplate interface to prevent screw loosening
due to effects of high temperatures on plastic.
Figure 1: Base Plate Assembly
Base
p
late
Alignment sleeve
AS22 Series
Miniature Kit Encoder

AS22 Series Application Note Miniature Kit Encoder
Broadcom AS-22-Kit-Encoder-AN101
2
Step 2: PCB Installation
Remove the alignment sleeve. Align the PCB onto the base
plate with the two pins on the base plate. Make sure the
connector side of the PCB is aligned with the groove on
base plate.
CAUTION! Do not touch optical sensor while handling the
PCB.
Figure 2: Align PCB to Pins
Figure 3: Ensure PCB Fully Seated on Base Plate
Step 3: Codewheel Gap Setting
Slide the spacer pin between the connector and latch until it
touches the motor shaft, as shown in Figure 4. Slide the hub
to the motor shaft with the code wheel facing the PCB, until
the hub flange touches the spacer pin.
Figure 4: Code Wheel Hub Assembly
Press down on the hub gently while tightening the set screw
with the hex wrench. The recommended torque to tighten
the set screw is 0.10 Nm to 0.13 Nm (0.9 in.lb to 1.15 in.lb).
A threadlocker can be applied to set the screw threads to
prevent the screw from unthreading during operation.
Remove the hex wrench and spacer pin.
CAUTION! DO NOT touch code the wheel pattern during
installation.
DO NOT scratch the code wheel during spacer
pin removal.
Figure 5: Tighten Set Screw on Hub
S
pacer pin
t
ouch motor
shaft
S
p
acer
p
in
Hub
Latch
Connector
Hex wrench

Broadcom AS-22-Kit-Encoder-AN101
3
AS22 Series Application Note Miniature Kit Encoder
Step 4: Cover Installation
Snap the cover down onto the base plate. Make sure the
two latches on base plate are fully engaged with the cover.
A click sound should be heard indicating the cover is
engaged properly.
Figure 6: Cover Installation
Figure 7: Complete Assembly of Encoder
The complete encoder assembly is shown in Figure 7. It is
now ready for cable attachment and operation.
Cover
Recommended Enclosure
AS22 is an optical encoder and sensitive to contamination. It is recommended that you install it inside an enclosure with
minimum IP5x.
Mounting Consideration
All dimensions are in mm.
NOTE: 1. No maximum shaft length limit for cover with hole option.

Broadcom AS-22-Kit-Encoder-AN101
4
AS22 Series Application Note Miniature Kit Encoder
Installation Precautions
1. Wear finger cots during installation.
2. DO NOT touch the code wheel pattern as it might cause contamination or scratches to code wheel.
3. DO NOT touch the optical sensor during PCB installation.
4. Be careful during spacer pin removal. Do not let the spacer touch the code wheel as it might scratch the code wheel.
5. Clean the code wheel with delicate task wipers with IPA. Do not use cotton buds (non lint free) as it will cause scratches
to the codewheel.
Troubleshooting Guide
For more information about the product specifications, refer to the product data sheet, AS22 Series Miniature Kit Encoder
Data Sheet, AS-22-Kit-Encoder-DS100.
ID Issue Cause Countermeasure
1 Double/multiple index,encoder
performance exceeds data sheet
specs limit
Contamination on code wheel Clean code wheel with delicate task wipers
with IPA.
Base plate mounting exceeds recommended
tolerance
Realign base plate using alignment sleeve.
Code wheel gap not within recommended
tolerance
Realign code wheel gap using spacer pin.
Shaft TIR exceeds recommended tolerance Reduce shaft TIR to within recommended
tolerance.
2 Encoder current consumption out
of spec
Detector IC faulty/shorted Consult factory.
3 No signal output Encoder power supply too low Check if Vcc versus ground is within 4.5V ~
5.5.
Poor connectivity between encoder output
pin and connector
Check pin and connector connectivity.
Wrong power supply polarity connection Check connector wire connection for Vcc
and ground is per the Pin Configuration table
in the data sheet.
Detector IC faulty Consult factory.

Broadcom, the pulse logo, Connecting everything, Avago Technologies, Avago, and the A logo are among the trademarks
of Broadcom and/or its affiliates in the United States, certain other countries and/or the EU.
Copyright © 2017 by Broadcom. All Rights Reserved.
The term “Broadcom” refers to Broadcom Limited and/or its subsidiaries. For more information, please visit
www.broadcom.com.
Broadcom reserves the right to make changes without further notice to any products or data herein to improve reliability,
function, or design. Information furnished by Broadcom is believed to be accurate and reliable. However, Broadcom does
not assume any liability arising out of the application or use of this information, nor the application or use of any product or
circuit described herein, neither does it convey any license under its patent rights nor the rights of others.