Here you'll find insights into PCB design, tech trends, assembly issues, and trending topics
in the general news media as they relate to printed circuit board technology.
As experts in the manufacture and assembly of printed circuit boards, we work to make our blog a helpful resource on PCB topics and the industries that we work with, including automotive, consumer electronics, aerospace and many more.
Physical analysis and verification are playing a more and more critical role in ensuring the success of complex, high-speed PCB board and system level designs. This article describes how to suppress and improve signal crosstalk in signal integrity analysis.
In the design of electronic systems, in order to avoid detours and save time, the anti-interference requirements should be fully considered and avoided, and remedial measures against interference should be avoided after the design is completed. There are three basic elements that form interference:
To get the best performance from an electronic circuit, the board is the support for the circuit components and devices in the electronics. Even if the schematic design of the circuit is correct and the printed circuit board is not properly designed, it will adversely affect the reliability of the electronic product. When designing a printed circuit board, it is important to use the correct method, follow the general principles of PCB design, and conform to the requirements of the anti-jamming design and the layout of the wires. In order to design a PCB of good quality and low cost, the following general principles should be followed:
10 questions and answers.
Differential mode current and common mode current.
Generalization of PCB design principles (1-30)
In general, the most basic process of designing a board can be divided into three major steps.
Electromagnetic interference is caused by electromagnetic effects. As components and wiring on the PCB become more and more dense, electromagnetic interference will occur if improperly designed. In order to suppress electromagnetic interference, the following measures can be taken:
4 methods and solutions
The so-called source synchronization means that the clock strobe signal CLK is transmitted by the driver chip along with the transmission data, and it does not use an independent clock source like the common clock synchronization. In the source synchronous data transceiving, the data is first sent to the receiving end, and the strobe clock is sent to the receiving end for sampling and latching the batch of data after a short time. The schematic diagram is shown in Figure 2. The timing analysis of source synchronization is simpler than the synchronization of common clocks. The analysis methods are very similar. The analysis formula is directly given below:
In order to successfully latch data into the device, the data signal must remain active at the input of the receiving chip for a sufficient amount of time to ensure that the signal is correctly latched by the clock sample. This time is called hold time. In the common clock bus, the receiver buffer latches the data with the second clock edge while latching the next data to the data transmitter on the driver side. Therefore, in order to satisfy the receiving end holding time, it is necessary to ensure that the valid data is latched into the receiving terminal flip-flop before the next data signal arrives, which requires that the delay of receiving the clock CLKA is smaller than the delay of receiving the data signal.
One of the two necessary conditions for data transmission: the data at the input of RECEIVER generally has the required setup time Tsetup, which means that the data must be valid before the minimum time valid for the clock, and the time at which the data signal arrives at the input should be early enough. At the clock signal, the inequality satisfied by the settling time can be derived.
In the field of network communication, in ATM switches, core routers, Gigabit Ethernet, and various gateway devices, the system data rate and clock rate continue to increase, and the operating frequency of the corresponding processor is also higher; data, voice, and image transmission.
In the design of power circuit, electromagnetic interference is one of the key factors affecting product performance. At present, there are many ways to solve the problem of EMI for engineers. Generally, methods for suppressing EMI include: EMI suppression coating, EMI simulation. Design and selection of suitable EMI suppression parts. This article will start with the PCB, and introduce the role and design skills of PCB layered stacking in controlling EMI radiation.
Conducting printed circuit board (PCB) design refers to the production of circuit boards at the lowest possible cost by designing schematic drawings and wiring layout. In the past, this usually required expensive tools, but now, with the availability of free high-performance software tools such as DesignSpark PCBs and design models, the speed of board designers has been greatly accelerated.
In high speed designs, the characteristic impedance of the controllable impedance plates and lines is one of the most important and common problems. First, let's look at the definition of a transmission line: a transmission line consists of two conductors of a certain length, one for transmitting signals and the other for receiving signals (remember that the "loop" replaces the concept of "ground"). In a multi-layer board, each line is part of a transmission line, and an adjacent reference plane can be used as a second line or loop. The key to a line becoming a "good performance" transmission line is to keep its characteristic impedance constant throughout the line.
In high-speed designs, the matching of impedance is related to the quality of the signal. The technique of impedance matching can be said to be rich and varied, but how to make a reasonable application in a specific system requires measuring various factors. For example, in our design in the system, many of them use the serial matching of the source segment. Why do you need to match and what kind of matching is used? For example, the majority of the differential matching uses the matching of the terminal; the clock uses the source segment matching.
There are many English abbreviations in the field of electrical interference.
The PCB board is divided into many layers. What are the techniques for the high four-layer routing? Let me introduce you to the following.