Anaheim Encoder ENCA2I SingleEnded 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
The ENC-A2I is a single-ended encoder with an optional third index chann\
el. This encoder requires a 
minimum shaft length of .445” and can be attached to shaft sizes rang\
ing from .079” to .394” in diameter. The 
ENC-A2I provides digital feedback information for motion control applica\
tions that require position, speed 
and/or direction control. This line of encoders is RoHS Compliant and REACH Certified.
Optical Encoder Module Update:
This new transmissive optical encoder module is designed to be an improv\
ed 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 capa\
ble 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. Physi\
cally, 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-A2I Single-Ended Encoder 
with Index Channel
• 50 to 5,000 Cycles Per Revolution (CPR)
• Tracks 0 to 300,000 Cycles Per Second
• 200 to 20,000 Pulses Per Revolution (PPR)
• Powered From a Single +5VDC Power Supply
• 2-Channel Quadrature  TTL Squarewave Outputs
• Third Channel Index
• Operating Temperature of -40° to +100° C
• Powered from a Single +5VDC Power Supply
• Allows for +/- .010” Axial Shaft Play
L010720
ENC - A2I - 0050 - 394 -  H  -  G
Base Options
3 = Base Mounting Holes Become 0.125”
A = Adds Self-Aligning Shoulder to Base
G = Adds 1.812” Mounting Ears to Base
R = Adds 3-Slot Adapter to Bottom of Base
Blank = Default
Index
I = Index
(3rd Channel)
Cover Options
E = Cover Extension
H = Hole in Cover
Blank = Default
CPR
0050 03601024
0096 04001250
0100 05002000
0192 05122048
0200 05402500
0250 07204000
0256 09004096
0360 10005000
Bore Size
079 = 2mm 236 = 6mm
118 = 3mm 250 = 1/4”
125 = 1/8” 276 = 7mm
156 = 5/32” 313 = 5/16”
157 = 4mm 315 = 8mm
188 = 3/16” 375 = 3/8”
197 = 5mm 394 = 10mm 
						

							910 East Orangefair Ln.  Anaheim, CA 92801     Tel. (714) 992-6990     Fax. (714) 992-0471     www.anaheimautomation.com
DIMENSIONS
COVER OPTIONS
Cover Options: Description
E - Option E-Option provides a cylindrical extension cover  for larger shafts.  The  
required shaft length is .445” to .795”.  
Note: E-option + R-Option the required shaft length is .570” to .920”.
H - Option Shaft < .375 - a .375” diameter hole is used
Shaft ≥ .375” or larger - a .500” diameter hole is used 
Minimum Shaft Length: greater than .445”           
 
Note: H-Option + R-Option the required shaft length is  > .570”      
Default The required length is .445” to .570”
Note: Default Option + R-Option the required shaft length is .570” to 
.695”
Note: Dimensions are in inches 
						

							910 East Orangefair Ln.  Anaheim, CA 92801     Tel. (714) 992-6990     Fax. (714) 992-0471     www.anaheimautomation.com
BASE OPTIONS
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
Timing Characteristics SymbolMinTy pMax 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 t1
10100 250 ns
Ch. I Fall After Ch. B or 
Ch. A  Rise t2
70150 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.) 
						

							SPECIFICATIONS
910 East Orangefair Ln.  Anaheim, CA 92801     Tel. (714) 992-6990     Fax. (714) 992-0471     www.anaheimautomation.com
Terminology Definition
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)
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.
ACCESSORIES
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=2mm236=6mm
118=3mm 250=1/4”
125=1/8” 276=7mm
157=4mm 313=5/15”
188=3/16” 375=3/8”
197=5mm 394=10mm
Centering Tools:
ENC-CTOOL - 250
The following cables are compatible with Anaheim 
Automation’s A2I 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.
Recommended Operating  Conditions Min
Max Units
Temperature (CPR < 2000) -40100 °C
Temperature (CPR ≥ 2000) -25100 °C
Load Capacitance -100 pF
Count Frequency (CPR ≤ 1250) -
300 kHz
Count Frequency
(CPR 2000-2500) -
360 kHz
Count Frequency (CPR 4000+) -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 < 500, no load
CPR ≥ 500 and < 2000, no load
CPR ≥ 2000, no load -
-
-
27
55
72 30
57
85 mA
mA
mA
Low-Level Output
I
OL = 8mA max (CPR < 2000)
I
OL = 5mA max (CPR ≥ 2000)
no load (CPR  ≥ 2000) -
-
--
-
0.25 0.5
0.5
- V
V
V
High-Level Output
I
OL = 8mA max (CPR < 2000)
I
OL = 5mA max (CPR ≥ 2000)
no load (CPR  < 2000)
no load (CPR  ≥ 2000) 2.0
2.0
-
- -
-
4.8
3.5 -
-
-
-V
V
V
V
Output Current Per Channel 
(CPR < 2000) -8.0
-8.0 mA
Output Current Per Channel 
(CPR ≥ 2000) -5
-5 mA
Output Rise Time (CPR < 2000) -11 0 -nS
Output Rise Time (CPR ≥ 2000) -50 -nS
Output Fall Time (CPR < 2000) -100 -nS
Output Fall Time (CPR ≥ 2000) -50 -nS