I Found One of the Chips I Designed 30 Years Ago

Описание: I recently rediscovered something from the very beginning of my career in integrated circuit design. One of the first chips I ever worked on.

Back in the late 1990s I worked with two other engineers on the SL1925 satellite zero-IF QPSK tuner IC. At the time I printed out the chip layout and framed it, and it has been hanging on the wall above my desk ever since.

Nearly 30 years later I’ve decided to revisit that chip.

I’ve managed to track down some of the original devices and ordered a few of them. When they arrive, the plan is to decap the chip, examine the silicon under a microscope, and compare the real layout on the die with the original design.

In future videos we’ll look at some of the circuits on the chip, including:

Bandgap and bias circuits
Automatic gain control (AGC)
Low-noise amplifier sections
How the bipolar process was used to build the transistors

It should be interesting to see how the actual silicon compares with the original design work from the 1990s.

This video also starts a new series called Thursday Night Chat, where I’ll share projects, experiments, and engineering stories alongside my regular Sunday videos on computer architecture and CPU design.

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If you’re interested in the full projects, simulation files, and deeper technical material, you can join me on Patreon:

  / rossmcgowanmaths  

There is also a free Patreon tier where I occasionally share resources and updates.

On this channel I build computers from the ground up:

Logic gates → CPU
CPU → instruction set architecture
ISA → compiler and high-level language

Start the full journey here:
Design a CPU – Full Playlist
   • Design a CPU 1 - The 8-Bit Machine