Currently high-speed PCB design widely used in the fields of communications, computing , graphics and video processing. The high-speed PCB design strategies used in these areas are not the same engineers .
In the field of telecommunications , PCB design is very complex, data transmission applications , voice and image transmission speed has been much higher than 500Mbps, people in the communications field in pursuit of faster introduction of more high-performance products , and the cost is not the first a 's . They will use more board layers , sufficient power and ground planes , any problems that may arise signal line speed will use discrete components to achieve a match. They have SI ( signal integrity ) and EMC ( electromagnetic compatibility ) experts to simulate and analyze the wiring before every PCB design engineers follow strict internal PCB design requirements . So the field of communications PCB design engineers often use this over a high-speed PCB design PCB design strategy.
Home computer motherboard PCB design area is the other extreme, the cost and effectiveness above all , PCB designers are always using the fastest, the best , highest-performance CPU chips, memory and graphics processing technology modules to form increasingly complex computer. The home computer motherboards are usually four shelves , some high-speed PCB design techniques difficult to apply to this area , so engineers in the field of home computers are usually studied using the method to design excessive speed PCB board, they should fully research PCB design the specific circumstances of those high-speed circuits to solve problems really exist .
The usual high-speed PCB design situation may not the same. The key components in high-speed PCB (CPU, DSP, FPGA, ASIC industry , etc.) vendors will provide information about the chip 's PCB design , PCB design data usually these reference PCB design and PCB design guidelines are given by way . However, there are two problems : First, device manufacturers and application understanding signal integrity there is also a process , and the system PCB design engineers always want to use the latest high-performance chips , so device manufacturers for the first time given PCB design guidelines may not be mature. So some device manufacturers in different periods will give multiple versions of PCB design guidelines . Secondly , PCB design constraints device manufacturers are usually given very demanding on the PCB design engineers to meet all of the PCB design rules can be very difficult. In the absence of simulation tools and background to these constraints do not understand the rules and meet all of the constraints is the only high-speed PCB design tools, such as PCB design strategy commonly referred to as over-constrained .
There is an article mentioned a backplane PCB design using surface mount resistors to achieve termination . Circuit board used more than 200 of such termination resistor . Imagine if you want to PCB Design 10 prototype model by changing this 200 termination resistors ensure the best results, it will be a huge workload. In this PCB design did not change any resistance value due to SI analysis software , it is indeed surprising.
So need to add high-speed PCB design simulation and analysis in the original PCB design flow, making it a complete PCB design and product development an integral part .
