In addition, when designing the circuit, we should pay special attention to the signal flow in the circuit, including the power supply. Land. Clock. A clear understanding of the key signal flow of the whole system can find the problems in the circuit faster, effectively reduce the debugging in the circuit and shorten the debugging time.
As mentioned earlier, the layout design of analog circuits is not only related to the performance and area of the chip, but also affects the function of the chip, making the chip completely invalid, so I want to talk about the layout design in analog circuit design. Now SOC has become the mainstream trend of chip design. Integrating analog circuits and digital circuits on one chip brings new difficulties to the layout design of analog circuits. There are two keys to analog circuit layout design: one is matching; The second is the wiring of power supply, grounding and key signals. Some predecessors said that what analog integrated circuits do is matching, especially high-performance analog integrated circuits. Matching is to reduce offset, reduce nonlinear distortion and improve * * * mode rejection ratio and power supply rejection ratio. Important measures to reduce the influence of process temperature and power supply voltage on chip performance, such as the ratio of two bipolar transistors in bandgap circuit is usually 1:8, in order to better match in layout design. Power supply. The design of grounding and key signal traces is mainly to reduce the interference of digital circuits to analog circuits and the interference of sensitive modules in analog circuits by other modules of analog circuits. The specific learning method is to learn the art of simulated layout first and master the basic design rules of simulated layout. Further study can only rely on accumulating experience in study and work.