Robust interface reference design for EnDat2.2 absolute encoders


Design files


This reference design demonstrates a robust interface to EnDat 2.2 Encoders. That shows EMC immunity, particularly immunity against fast transients such as inverter switching noise. The Encoder supply voltage is configurable and integrates protection against short circuit to prevent damage due to cable short or miss wiring and diagnostic feedback to detect the fault. The logic interface supports 3.3V down to 1.8V I/O. The design is compatible to TI LaunchPad™ development kit for easy evaluation of EnDat2.2 with the C2000™ MCU. This design has been tested up to 100-m cable length with several EnDat 2.2 encoders.

  • Exceed HEIDENHAIN EnDat 2.2 clock frequency of 16 MHz up to 20m, 8 MHz up to 100m cable length
  • Highly robust interface with high EMC immunity thanks to wide supply range 3.3-V to 5V, half-duplex RS-485 transceiver (THVD1450), 50-Mbaud, with ±15V common mode range, 16-kV IEC-ESD and 4-kV EFT
  • Design tested to meet EMC immunity requirements for ESD(IEC61000-4-2), EFT(IEC61000-4-4) and surge(IEC61000-4-5) with levels and pass criterion  according to IEC61800-3
  • Configurable encoder Voltage default 8 V with low-ripple (<50mVpp) output meets Endat2.2 specification
  • Encoder supply protected 250 mA nominal output current with short circuit protection and power good feedback for diagnostic
  • Logic interface default 3.3 V I/O to host processors like a C2000 MCU or Sitara® processor to run the EnDat 2.2 master software
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A fully assembled board has been developed for testing and performance validation only, and is not available for sale.

Design files & products

Design files

Download ready-to-use system files to speed your design process.

TIDUEL7.PDF (16528 K)

Reference design overview and verified performance test data


Detailed schematic diagram for design layout and components


Complete listing of design components, reference designators, and manufacturers/part numbers


Detailed overview of design layout for component placement

TIDRYY5.ZIP (1240 K)

Files used for 3D models or 2D drawings of IC components

TIDCFA2.ZIP (1311 K)

Design file that contains information on physical board layer of design PCB

TIDRYY4.PDF (1079 K)

PCB layer plot file used for generating PCB design layout


Includes TI products in the design and potential alternatives.

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Technical documentation

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* Design guide Robust interface reference design for EnDat 2.2 absolute encoders Feb. 04, 2019

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