The ESD Handbook

13ESD Analog Design

This chapter discusses analog design layout practices of interdigitated design layout and common centroid concepts in one- and two-dimensions [1–10]. These concepts are implemented into electrostatic discharge (ESD) networks and the co-synthesis of analog circuits and ESD networks [5, 11–63]

13.1 Analog Design: Local Matching

Analog design local matching is important for segments within a given circuit element or circuit elements within a given circuit [1–10]. For example, local matching is important in differential pair circuits and current mirrors. Many of the analog design matching practices are also good ESD design practices, which will be discussed.

13.2 Analog Design: Global Matching

Analog design global matching is important for circuits that are identical elements but physically spaced around a semiconductor chip [1–10]. For example, global matching is important in MUX circuits where the inputs are placed at different physical locations within a semiconductor chip. Orientation can also influence the linewidth of identical circuits both locally and globally. On a macroscopic full-chip scale, there are variations in the photolithography and etching from the top to bottom of a semiconductor chip. In the design of a semiconductor chip, these can be compensated with a pre-knowledge of the photolithography and etch variations of a technology.

An ESD design practice is to maintain the same x–y orientation of ESD circuits in a semiconductor chip to minimize ...