3/Signal integrity solution
The signal integrity problem is not caused by a single factor, but is caused by many factors in the board design. The main signal integrity issues include reflection, ringing, ground bounce, crosstalk, etc. The following mainly introduces crosstalk and reflection. Solution.
4/Signal Integrity Analysis Modeling
Reasonable circuit modeling and simulation is the most common signal integrity solution. In high-speed circuit design, simulation analysis shows more and more advantages. It gives designers accurate and intuitive design results, making it easy to identify problems early and modify them in time to shorten design time and reduce design costs. There are three commonly used: SPICE model, IBIS model, Verilog-A model.
SPICE is a powerful general purpose analog circuit simulator. It consists of two parts: the Model Equation and the Model Parameters. Since the model equations are provided, the SPICE model can be closely linked to the simulator's algorithm for better analysis efficiency and analysis results; the IBIS model is dedicated to digital signal integrity at the PCB level and system level. Analytical model. It uses I/V and V/T tables to describe the characteristics of digital integrated circuit I/O cells and pins. The analysis accuracy of the IBIS model mainly depends on the data points of the 1/V and V/T tables and the accuracy of the data. Degree, compared with the SPICE model, the calculation of the IBIS model is small.