Reverse Engineering a 90s Tektronix 5Gsps Oscilloscope
2025-05-05
This blog post details a reverse engineering effort on a Tektronix TDS684B oscilloscope, renowned for its impressive 5Gsps sample rate in the 1990s. By examining the internal components and taking measurements, the author discovered a key component: an unidentified ADG286D chip, likely an analog CCD FIFO memory. This chip captures analog signals at extremely high speed before digitizing them at a much slower 8MHz rate. Despite significant noise on the ADC input, the final displayed waveform is remarkably clean, hinting at sophisticated signal processing techniques. The analysis reveals the ingenious design that achieved such high sampling rates with the technology available at the time.