EC35 Optical Commutation Kit Encoder

EC35 Features

  • Now 500 to 60,000 CPR
  • Quick, simple assembly
  • A/B/Z differential outputs
  • U/V/W commutation outputs (differential or open-collector)
  • 2,000 to 240,000 quadrature states per rev.
  • Frequency response from DC up to 1 MHz
  • Fits shaft diameters from 0.197 in. (5mm) to 0.375 in. (3/8 in.)
  • Single 5V supply

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EC35 Product Description

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The EC35 quick assembly optical commutation encoder is designed for high volume, low cost, OEM motion control applications. The EC35 provides A/B/Z incremental outputs and U/V/W outputs for brushless motor commutation.

The EC35 is designed to be a one-time installation that mounts to the motor using 2 screws on a 1.28" or 1.812" diameter bolt circle. The precision machined encoder hubdisk pushes on when the encoder assembly is put on the motor shaft. This design securely grips the shaft without set screws. A built-in, removable spacer tool ensures that the encoder disk is automatically set to the correct gap when the encoder housing is mounted. The encoder can be "timed" by rotating a ring on the assembly and pressing the ring in with a simple tool to lock everything into place.

The EC35 is powered by a single 5V supply and comes with a 15-pin connector that provides differential outputs for A/B/Z and U/V/W. Open-collector U/V/W outputs are available as an option. The EC35 can obtain single-ended output by only using the + outputs of each differential pair. The internal 26C31 line drivers can source and sink 20 mA at TTL levels. The recommended differential receiver is the industry-standard 26C32. Maximum noise immunity is achieved when the differential receiver is terminated with a 150 Ω resistor in series with a .0047 μF capacitor placed across each differential pair.

Please Note: Due to the EC35's push-on hub design, it is recommended for use as a one-time installation.

Product Specifications

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Operating Temperature -20 to 105 C
Electrostatic Discharge, IEC 61000-4-2 ±12 kV
Vibration (10Hz to 2kHz, sinusoidal) 20  G
Shock (6 milliseconds, half-sine) 75 G


Max. Shaft Axial Play ±0.003 in.
Max. Shaft Runout 0.001 T.I.R. in.
Max. Acceleration 250000 rad/sec²

Maximum RPM, CPR ≤ 2500
e.x. CPR = 2500, max. rpm = 9600

((24 x 10^6) / CPR) RPM
Maximum RPM, CPR = 4000 12000 RPM
Maximum RPM, CPR = 5000 9600 RPM
Maximum RPM, CPR = 10000 6000 RPM
Maximum RPM, CPR = 20000 3000 RPM
Maximum RPM, CPR = 40000 1440 RPM
Maximum RPM, CPR = 60000 960 RPM
Codewheel Moment of Inertia 6.48 x 10-5 oz-in-s2
Required Shaft Length 0.500 to 0.565 in.
Mounting Screw Torque 2-3 in-lbs
Technical Bulletin TB1001 - Shaft and Bore Tolerances Download


Supply Current
  CPR ≤ 2500
  CPR > 2500


no output load, max. frequency output
Supply Voltage 4.5 5.0 5.5 V  
Differential High Level Output 2.5 3.5   V loh = -8 mA
Differential Low Level Output     0.5  V lol = 8 mA
Differential Rise/Fall Time   100   ns  
Open collector pullup voltage     30 V lload = 100 mA
Open collector "on" resistance   0.2   ohm lload = 100 mA
Frequency Response,
CPR ≤ 2,500
    400 kHz  
Frequency Response,
CPR = 4,000 & 5000
    800 kHz  
Frequency Response,
CPR = 10,000
    1 MHz  
Frequency Response,
CPR = 20,000 / 40,000 / 60,000
    960 kHz  



Symmetry, S1, S2  108 180  252 elec. deg.
Quadrature Delay, Q  45 90  135 elec. deg.
Index Width, W  45 90  135 elec. deg.

A leads B for CCW shaft rotation, and B leads A for CW rotation viewed from the top side of the encoder.



Part #: SCREW-256-188-SH
Description: Socket Head Cap, #2-56 UNC x 3/16"
Use: Base Mounting
Quantity Required: 2
Screws are included

Part #: SCREW-M25-5MM-PH
Description: Pan Head, Phillips M2.5 x 0.45 x 5mm
Use: Base Mounting
Quantity Required: 2

Part #: SCREW-M25-5MM-BH
Description: Button Head Cap, M2.5 x 0.45 x 5mm
Use: Base Mounting
Quantity Required: 2
Screws are included


State width, 4 pole  27 30  33 angular deg.
State width, 6 pole  17 20  23 angular deg.
State width, 8 pole  12 15  18 angular deg.
State width, 10 pole  9 12  15 angular deg.
State width, 12 pole  7 10  13 angular deg.


Pin "D" Output Option "C" Output Option "0" pole Option
1 A+ (A Quadrature) A+ (A Quadrature) A+ (A Quadrature)
2 A- A- A-
3 B+ (B Quadrature) B+ (B Quadrature) B+ (B Quadrature)
4 B- B- B-
5 Z+ (Index) Z+ (Index) Z+ (Index)
6 Z- Z- Z-
7 U+ (U Commutation) U (Open collector) no connection
8 U- no connection no connection
9 V+ (V Commutation) V (Open collector) no connection
10 V- no connection no connection
11 W+ (W Commutation) W (Open collector) no connection
12 W- no connection no connection
13 +5V power  +5V power +5V power
15 no connection  no connection no connection

Additional Information

Product Notes

  • Cables and connectors are not included and must be ordered separately.
  • US Digital® warrants its products against defects in materials and workmanship for two years. See complete warranty for details.


Assembly Instructions

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