Page 102 - The Art and Science of Analog Circuit Design

William H. Gross

8. One Trip Down the 1C

Development Road

This is the story of the last 1C that I developed. I use the word develop
rather than design because there is so much more involved in the making
of a standard part than just the circuit design and layout. My goal is to
give the reader an idea of what is involved in this total development. The
majority of this description will be on the evolution of the product defini-
tion and the circuit design since that is my major responsibility. I will
also describe many of the other important steps that are part of the 1C
development. To give the reader an idea of what is required, I made an
approximate list of the steps involved in the development of an 1C.
The steps in the development of a new 1C:

1. Definition
2. Circuit design
3. Re-definition
4. More circuit design
5. The first finalizing of the specifications
6. Test system definition
7. Mask design
8. Test system design
9. Waiting for wafers to be made
10. Evaluation
11. Test system debug
12. Redesign (circuit & masks)
13. More waiting
14. Finalizing the test system
15. 1C characterization
16. Setting the real specifications
17. Pricing
18. Writing the data sheet
19. Promotion
20. Yield enhancements
Circuit design (steps 2,4, and 12) is what we usually think of when
we talk about 1C design. As you can see, it is only a small part of the 1C
development. At some companies, particularly those that do custom ICs,
circuit design is all the design engineers do. In the ideal world of some
MB As, the customer does the definition, the designer makes the 1C, the

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