Anaheim Encoder ENCA3I High Resolution Encoder with Index Spec Sheet

							FEATURES
ORDERING INFORMATION
910 East Orangefair Ln.  Anaheim, CA 92801     Tel. (714) 992-6990      Fax. (714) 992-0471     www.anaheimautomation.com
DESCRIPTION
L010724
ENC-A3I Single-Ended High Resolution
Encoder with Index ChannelENC-A3I Single-Ended High Resolution
Encoder with Index Channel
• 100 to 10,000 Cycles Per Revolution (CPR)
• 400 to 40,000 Pulses Per Revolution (PPR)
• Tracks 0 to 300,000 Cycles Per Second
• 2-Channel Quadrature TTL Squarewave Outputs
• Third Channel Index
• Operating Temperature of -40° to +100° C
• Accepts +/- 0.010” Axial Shaft Play
• Powered from a Single +5VDC Power Supply
• RoHS Compliant and REACH Certified
Note: H, M and T are the only options available for bore sizes exceeding .394 inches.
          Base must be either M or T when Bore size is 472.
          Cover must be H when Bore size is greater than 394.
The ENC-A3I, is a high resolution single-ended encoder with an optional third index channel. 
This encoder 
requires a minimum shaft length of .445” and can be attached to shaft sizes ranging from .079” to 1” in 
diameter. The ENC-A3I provides digital feedback information for motion control applications that require 
position, speed and/or direction control.
New Optical Encoder Module:
This new transmissive optical encoder module was designed to be an improved replacement for the  Avago 
HEDS-9000 series encoder module. This module is designed to detect rotary position when used with a code 
wheel. The new module consists of a lensed LED source and a monolithic detector IC enclosed in a small 
polymer package. The new module uses phased array detector technology to provide superior performance 
and greater tolerances over traditional aperture mask type encoders.  The new module provides digital A & 
B quadrature outputs with an optional third output index channel. Each module is resolution specific and is 
matched to the resolution of a code wheel. All standard resolutions offered by the HEDS-9000 series encoder 
module, as well as additional resolutions, are now supported by the new module.  The new module operates 
with a single 5V supply and provides single ended outputs which are capable of both sinking and sourcing 
8mA at TTL levels. An internal 0.1 uF decoupling capacitor is designed into the new module to provide 
enhanced noise immunity over the HEDS-9000 series encoder modules. Physically , the new module has no 
external wire loops which can interfere when mounting. The connector pins are 0.051” shorter than HEDS 
modules, while still providing .30” insertion depth.
ENC - A3I - 1000 - 394 -  H  -  T
CPR
0100 2500
0200 3600
0400 4000
0500 4096
0512 5000
1000 7200
1024 8000
1800 8192
2000 10000
2048
Index
I = Index
(3rd Channel)
Bore Size
079 = 2mm 250 = 1/4”551 = 14mm
118 = 3mm 313 = 5/15” 625 = 5/8”
125 = 1/8” 315 = 8mm 750 = 3/4”
156 = 5/32” 375 = 3/8”787 = 20mm
157 = 4mm 394 = 10mm 875 = 7/8”
188 = 3/16” 472 = 12mm 984 = 25mm
197 = 5mm 500 = 1/2”1000 = 1”
236 = 6mm
Cover Options
E = Cover Extension
H = Hole in Cover
Blank = Default
Base Options
3 = Base Mounting Holes Become 0.125”
M = 4-Hole Mounting Adapter Plate
T = Transfer Adhesive
Blank = Default 
						

							910 East Orangefair Ln.  Anaheim, CA 92801     Tel. (714) 992-6990     Fax. (714) 992-0471     www.anaheimautomation.com
DIMENSIONS: DEFAULT OPTION
ENCODER COVER OPTIONS
Cover Options: Description
E - Option E-Option provides a cylindrical extension cover  for larger shafts.  For 
shaft diameters ≤ .472”, the required shaft length is .445” to .670”.  
Note: E-option + M-Option the required shaft length is .570” to .795”.
H - Option Shaft ≤ 0.5” - a 0.55” diameter hole is used
Shaft > 0.5” diameter hole is used
Required Shaft Length: > .445” 
 
Note: H-Option + M-option the required shaft lenght is > .570”
Default Option The required length is .445” to .525”
Note: Default Option + M-Option the required shaft length is .570” to 
.650”
Note: All Dimensions are in (in) 
						

							910 East Orangefair Ln.  Anaheim, CA 92801     Tel. (714) 992-6990     Fax. (714) 992-0471     www.anaheimautomation.com
PIN/TIMING DIAGRAMS
SINGLE-ENDED ENCODER PINOUTTOP OF ENCODER FACING PLUG
Pin #Function
1 Ground
2 Index
3 Channel A
4 +5VDC Input
5 Channel B
Base Options: Description
3 - Option Makes all five hole diameters 0.125”.  
M - Option Adds 4-hole mounting adapter plate.  Mounting plates requires additional .125” shaft 
length.  A .5” diameter hole is provided for shafts ≤ 10mm and a 1.5”diameter hole is 
provided for shafts > 10mm.
T - Option A pre-applied transfer adhesive .005” thick (with peel-off backing) is available for “stick” 
on mounting
ENCODER BASE OPTIONSNote: All Dimensions are in (in)
Timing Characteristics
SymbolMinTy p Max Units
Cycle Error C-3.0 5.5 °e
Symmetry X,Y150180 210 °e
Quadrature Z6090120 °e
Index Pulse Width Po6090120 °e
Ch. I Rise After Ch. B or Ch. A Fall t110100 250 ns
Ch. I Fall After Ch. B or Ch. A Rise t270150 300 ns
(Note: Base Mounting Screws are NOT included. #2-56 or #4-40 screws can\
 be used to mount the base to your mounting surface.) 
						

							ELECTRICAL SPECIFICATIONS
910 East Orangefair Ln.  Anaheim, CA 92801     Tel. (714) 992-6990     Fax. (714) 992-0471     www.anaheimautomation.com
ACCESSORIES
Model # Description
CPR(N): The Number of Cycles Per Revolution
One Shaft Rotation: 360 mechanical degrees, N cycles
One Electrical Degree (°e): 1/360th of one cycle
One Cycle (C): 360 electrical degrees (°e). Each cycle can 
be decoded into 1 or 4 codes, referred to as 
X1 or X4 resolution multiplication
Symmetry: A measure of the relationship between (X) 
and (Y) in electrical degrees, nominally 180 
°e
Quadrature (Z): The phase lag or lead between channels A 
and B in electrical degrees, nominally 90 °e
Index (CH I): The Index Output goes high once per 
revolution, coincident with the low states of 
channels A and B, nominally 1/4 of one cycle 
(90°e)
Cable Part Number
Length
ENC-CBL-AA4032 1 ft.
ENC-CBL-AA4032-04 4 ft. 
ENC-CBL-AA4032-10 10 ft.
Cables:
Bore Size
079=2mm250=1/4”551=14mm
118=3mm 313=5/15” 625=5/8”
125=1/8” 315=8mm 750=3/4”
156=5/32” 375=3/8”787=20mm
157=4mm 394=10mm 875=7/8”
188=3/16” 472=12mm 984=25mm
197=5mm 500=1/2”1000=1”
236=6mm
Centering Tools:
ENC-CTOOL - 250
The following cables are compatible with Anaheim 
Automation’s A3I series encoder. Select a cable 
length from the table below:  Centering tools are optional, but recommended for a 
more precise installation. 
NOTE: For pricing and other information on cables 
and centering tools, please visit Accessories on our 
website.
Parameter MaxUnits
Vibration (5 to 2kHz) 20g
Shaft Axial Play +/- 0.01in.
Shaft Eccentricity Plus Radial Play 0.004in.
Acceleration 250,000rad/sec
2
* Unloaded high level output voltage is 4.80V typically, 4.2V minimum.
Recommended Operating 
Conditions Min
MaxUnits
Temperature (CPR < 2000) -40100 °C
Temperature (CPR ≥ 2000) -25100 °C
Load Capacitance -100 pF
Count Frequency (CPR ≤ 2500) -
300 kHz
Count Frequency
(CPR > 2500, and ≤ 5000) -
360 kHz
Count Frequency (CPR 5000+) -720 kHz
Speed Calculation Units
CPR ≤ 1250  18x10
6 / CPRRPM
CPR 2000-2500 21.6x10
6 / CPRRPM
CPR 4000+ 43.2x10
6 / CPRRPM
*60,000 RPM is the maximum RPM due to mechanical limitations.
Parameter MinTy pMax Units
Supply Voltage 4.55.05.5 Volts
Supply Current
CPR < 1000, no load
CPR ≥ 1000 and < 3600, no load
CPR ≥ 3600, no load -
-
-
27
54
72 33
62
85 mA
mA
mA
Low-Level Output
I
OL = 8mA max (CPR < 3600)
I
OL = 5mA max (CPR ≥ 3600)
no load (CPR  < 3600)
no load (CPR  ≥ 3600) -
-
-
--
-
0.25
0.25 0.5
0.5
-
- V
V
V
V
High-Level Output
I
OL = 8mA max (CPR < 3600)
I
OL = 5mA max (CPR ≥ 3600)
no load (CPR  < 3600)
no load (CPR  ≥ 3600) 2.0
2.0
-
- -
-
4.8
3.5 -
-
-
-V
V
V
V
Output Current Per Channel 
(CPR < 3600) -8.0
-8.0 mA
Output Current Per Channel 
(CPR ≥ 3600) -5.0
-5.0 mA
Output Rise Time (CPR < 3600) -11 0 -nS
Output Rise Time (CPR ≥ 3600) -50 -nS
Output Fall Time (CPR < 3600) -36 -nS
Output Fall Time (CPR ≥ 3600) -50 -nS