In order to design a circuit, you must have the most basic knowledge of components and know the parameters and characteristics of components. Understand the components of various circuits; Familiar with analog circuit and digital circuit, and can program. It’s best to start with making power supply first; Then learn more about modern high-tech products and look at their hardware structure.
1. If FPGA devices are included in the designed circuit system, Quartus II software must be used to verify the pin allocation before drawing the schematic diagram( Some special pins in FPGA can’t be used as common io
2. From top to bottom, the four layers are signal plane layer, ground layer, power layer and signal plane layer; From top to bottom, the six layers are: signal plane layer, ground layer, signal inner layer, signal inner layer, power supply layer and signal plane layer. For the board with more than 6 layers (the advantage is: anti-interference radiation), the internal electric layer is preferred, and the plane layer is selected if it can’t go, and the wiring from the ground or power layer is forbidden (reason: the power layer will be divided, resulting in parasitic effect).
3. Multi power system wiring: if FPGA + DSP system makes 6-layer board, generally there will be at least 3.3V + 1.2V + 1.8V + 5V.
Generally, 3.3V is the main power supply. It is easy to lay the power layer directly and connect the global power network through the via.
5V may be the power input in general, only need to lay copper in a small area. And try to be as thick as possible (you ask me how thick I should be – as thick as I can be, the thicker the better)
1.2V and 1.8V are the core power supplies (if directly connected by wire, it will encounter great difficulties when facing BGA devices). When layout, try to separate 1.2V and 1.8V, and let the components connected in 1.2V or 1.8V be arranged in a compact area and connected by copper sheet