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