Out-of-Band Ethernet Synchronization - Custom PHY and Analog Front End
Overview
To improve Ethernet synchronization without disturbing normal traffic, this project needed direct access to the physical layer and a front end that could preserve signal integrity at high speed. This project involved the development of a custom mixed-signal architecture incorporating a Ethernet PHY, precision clock generation, and FPGA-based signal processing to encode and decode an out-of-band timing channel.
The resulting platform demonstrated reliable synchronization performance through the seamless integration of high-speed data converters, analog signal conditioning, and custom FPGA gateware. Designed as a reusable subsystem, the solution provided a flexible foundation for further system integration, validation, and synchronization research.
Key Contributions:
- Development of a custom Ethernet PHY using high-speed mixed-signal circuitry
- Integration of AD9481 (8-bit, 250 MSPS) ADC and AD9741 dual-channel (8-bit, 250 MSPS) DAC
- Analog front-end design utilizing ADL5562 LNA (6 / 12 / 15.5 dB gain) and LMH6517 VGA (-9.5 to 22 dB gain)
- Precision clocking architecture based on the Si570 programmable oscillator and NB6N11S LVDS buffer