1.4 Introduction to Analog Design Flow with opensource tools

The analog design flow using open-source tools involves several stages, each of which utilizes different open-source tools. Here’s a high-level overview of the process:

1. Schematic Design: The design process begins with a schematic design, which defines the functionality of the circuit. This is done using a tool like Xschem.
2. Simulation: The schematic design is then simulated to verify its functionality. This is done using a simulator like Ngspice.
3. Layout Design: Once the schematic design is verified, a physical layout of the circuit is created. This is done using a tool like Magic.
4. Layout Verification: The layout is then verified for any violations of the design rules of the fabrication process. This includes Design Rule Checking (DRC) and Layout Versus Schematic (LVS) checks.
5. Parasitic Extraction: After the layout verification, parasitic elements are extracted from the layout. These parasitics are then used to perform post-layout simulation.
6. Post-Layout Simulation: The design is then simulated again, but this time with the extracted parasitics. This gives a more accurate representation of how the circuit will perform when fabricated.

References

1. Tim Edwards, Introduction to the SkyWater PDK, 2021.