E4T Miniature Optical Kit Encoder

E4T Features

  • Push-on hub - spring loaded collet design
  • Minimum shaft length of .275 in.
  • Fits shaft diameters of .079 in. to .250 in.
  • 100 to 1,000 cycles per revolution (CPR)
  • 400 to 4,000 pulses per revolution (PPR)
  • Single +5V supply

See more info below

Configure the E4T

E4T Product Description

Restriction of Hazardous Substances

The E4T miniature transmissive optical encoder is designed to provide digital quadrature encoder feedback for high volume, limited space applications. The E4T is designed to be a drop-in replacement for the E4P and offers higher maximum speed and increased output drive. The E4T utilizes an innovative, push-on encoder disk that accepts shaft diameters of 2.0mm to .250 in.

The single-ended output version is connected using a 4-conductor, high retention, polarized, 1.25mm pitch connector. The differential output version uses a similar 6-pin connector. Mating cables and connectors (see the Cables/Connectors web page) are not included and are available separately.

Please Note: Due to the E4T's push-on hub design, it is recommended for use as a one-time installation.

Product Specifications


Operating Temperature -20 to 100 C
Electrostatic Discharge, IEC 61000-4-2
Single-ended (-S option)
Differential (-D option)

± 12
± 7

Vibration (10Hz to 2kHz, sinusoidal) 20 G
Shock (6 milliseconds, half-sine) 75 G


Max. Shaft Axial Play ± .010 in.
Max. Shaft Runout (TIR) .002 in.
Max. Acceleration 250,000 rad/sec²

Maximum RPM (1)


Maximum A/B Frequency
e.x. CPR = 200, Max. RPM = 30000

minimum value of
((6 x 10^6)/CPR)
and (60000)





Max. Codewheel Moment of Inertia 5.1 x 10^-7 oz-in-s²
Mounting Screw Size
Default (D-option base)
Metric (M-option base)

#3-48 x 3/16"
M2.5, length 4mm
Screw Bolt Circle Diameter .586 ±.005 in.
Minimum Shaft Length (2) .275 in.
Maximum Shaft Length (2) .395 (D option) /
no limit (H option) 
Mounting Screw Torque 2-3 in-lbs
Technical Bulletin TB1001 - Shaft and Bore Tolerances Download

(1) 60000 RPM is the maximum rpm due to mechanical considerations. The maximum RPM due to the module's maximum frequency response is dependent upon the module’s resolution (CPR).

(2) Including axial play.

Single-Ended Electrical

Supply Voltage 4.5 5.0 5.5 V  
Supply Current   25 30 mA CPR ≤ 500, no load
  34 42 mA CPR > 500, no load
Low-level Output     0.4 V CPR ≤ 500, IOL= 8 mA
CPR > 500, IOL= 5 mA
  0.035   V no load
High-level Output 2.4     V CPR ≤ 500, IOH= -8 mA
CPR > 500, IOH= -5 mA
  4.0   V no load
Output Rise Time   100   ns no load
Output Fall Time   50   ns no load

Differential Electrical

Supply Voltage 4.5 5.0 5.5 V  
Supply Current   27 32 mA CPR ≤ 500, no load
  36 44 mA CPR > 500, no load
Single-Ended Output Voltage High 4.75 5.0   V Min. @ 25mA load, Typ. @ no load
Single-Ended Output Voltage Low   0.25 0.60 V Typ. @ no load, Max. @ 4.5mA load
Differential Output Voltage 3.0 3.8   V RL = 100 ohm
Differential Output Rise/Fall Time     20 ns  

Phase Relationship

Symmetry, S 105 180 255 electrical degrees
Quadrature Delay, Q 30 90 150 electrical degrees

(1) A leads B for clockwise shaft rotation, B leads A for counter clockwise shaft rotation viewed from the cover side of the encoder.

(2) Typical values represent the encoder performance at typical mounting alignment, whereas the maximum values represent the encoder performance across the range of recommended mounting tolerance.


Pin Description Pin Description
1 +5VDC power 1 Ground
2 A channel 2 A channel
3 Ground 3 A- channel
4 B channel 4 +5VDC power
    5 B channel
    6 B- channel

(1) 4-pin single-ended mating connector is CON-MIC4
(2) 6-pin differential mating connector is CON-MIC6



The H-option adds a 0.295" diameter hole in the cover for the shaft to pass through.


Provides alternate metric M2.5, length 4mm screws. When M-option is NOT specified the default is #3-48 x 3/16" screws.


1. Centering Tool*

Part #: MCTOOL - (Shaft Diameter)
Description: This reusable tool is used to accurately center the E4T base on the shaft.

2. Spacer Tool*

Part #: SPACER-E4T
Description: This reusable tool is used to properly space the codewheel from the encoder.

*Both the MCTOOL and SPACER-E4T tools are included with all packaging options.

3. Screws

Part #: SCREW-348-188-PH
Description: Pan Head, Philips #3-48 UNC x 3/16"
Use: Base Mounting
Quantity Required: 2
Screws are included with default base option

Part #: SCREW-M25-4MM-BH
Description: Button Head Cap, M2.5 x 0.45 x 4mm
Use: Base Mounting
Quantity Required: 2
Screws are included with metric base option

Product Change Notifications

Title Date Description Download
E4T and S4T Cover and Base Update - PCN 7192 3/3/2022 As part of our ongoing continuous improvement efforts, and to avoid any potential disruption to our supply chain, US Digital has decided to standardize our plastic material. Based on this, the E4T and S4T encoder cover and base will change from PBT (Polybutylene Terephthalate) to PC (polycarbonate). Download
E4T, E8T Packaging - PCN 7195 2/15/2022 As part of our ongoing continuous improvement efforts, US Digital is implementing a change to our packaging options for our E4T and E8T kit encoders. Download
Updated PCB for E4T and S4T - PCN 6466 1/29/2018 This notice is to inform our customers of a PCB design change that is being implemented for all of the E4T and S4T product lines. The new PCBs will improve overall product performance and enhance robustness of these product lines. The new PCBs can be identified by their blue color (instead of black) and have two mounting holes that mate with the base plate instead of one hole and one slot. This change has no impact on form, fit or function for either the E4T or S4T. Download
E4T, S4T and E8T Laser Markings - PCN 6227 8/8/2017 This notification is to inform our customers of a change to product markings for the E4T, E8T, and S4T series of encoders. The new marking will be utilized across all three product lines. We are making this change to improve readability for our customers and to provide consistency across the product lines. Download

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

Product Change Notifications

Press Releases

3D Model Downloads

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