Reference Design for an Interface to a Position Encoder with EnDat 2.2
TIDA-00172
This product has been released to the market and is available for purchase. For some products, newer alternatives may be available.
This product has been released to the market and is available for purchase. For some products, newer alternatives may be available.
See the Important Notice and Disclaimer covering reference designs and other TI resources.
Key Document
- Interface to EnDat 2.2 Position Encoder Design Guide
(PDF 7780 KB)
28 May 2014
Description
This TI Design implements a hardware interface solution based on the HEIDENHAIN EnDat 2.2 standard for position or rotary encoders. The building blocks include the power supply for the encoder – with innovative smart e-Fuse technology - and robust half-duplex RS485 transceivers, including line termination and EMC protection. An auxiliary power supply and logic level interface with adjustable I/O voltage level is provided to connect to subsequent MCUs and MPUs that would run the EnDat 2.2 Master protocol stack. This design is fully tested to meet EMC immunity requirements for ESD, Fast Transient Burst and Surge according to IEC61800-3.
Features
- Design meets EMC immunity requirements for ESD, Fast Transient Burst and Surge according to IEC61800-3
- High-speed RS-485 transceivers robust to 15kV ESD immunity
- Wide input (15-30VDC) high-efficiency (>85%) DCDC power supply configurable from 3.6V to 14V (defaulted to 8V) with 200mA, low-ripple (<20mVpp) output
- Protected power supply with innovative eFuse technology to protect against over-current, over-power, over- and under-voltage and disconnect in case of fault.
- Option to shut down encoder power supply in case of fault or to save power when no encoder is connected.
- Level shifter to support 3.3V, 2.5V or 1.8V I/O interface to processors like Sitara AM4x for EnDat 2.2 Master.
See the Important Notice and Disclaimer covering reference designs and other TI resources.
