where the capacitor in the circuit to AC current obstruction effect is called capacitive reactance, inductance in the circuit to AC current obstruction effect is called inductive reactance, capacitance and inductance in the circuit to AC current caused by
With the success of high-speed PCB design, the contribution to EMI has been paid more and more attention. Almost 60% EMI problems can be controlled and solved by high-speed PCB. I have done EMI design for 4 years, and I have some ideas to communicate with
Nowadays PCB design time is getting shorter, smaller and smaller board space, higher and higher device density, extremely demanding layout rules and large size components make the designer's job more difficult.
layout designers must ensure that their work is fully documented and that the final product is ready to be included in the main electronic system of their design.
The other is ground (or low potential) noise, that is, ground noise caused by the potential difference between ground wires in various parts of the system or by the presence of ground impedance.
high speed circuit design technology has become the electronic system designers must take the design means. The controllability of the design process can only be achieved by using the design techniques of high speed circuit designers.
n electronic product that does not conform to EMC specifications is not an acceptable electronic design. In addition to meeting market functional requirements, design products must also adopt appropriate design techniques to prevent or relieve EMI effects
In practical EMI shielding, the electromagnetic shielding efficiency depends largely on the physical structure of the chassis, namely, the continuity of conduction. The seams and openings in the chassis are leakage sources of electromagnetic waves.
Here, it is temporarily classified into two categories: one is electrical related safety spacing, one is non-electrical related safety spacing.
Our electronic products are often more than 60% - reliability problems are in the PCB design of the electronic circuit board; Relevant theoretical and practical experience is required for working and performing PCBS;
The most effective way to improve the density of PCB circuit board is to reduce the number of through holes, and precisely set blind holes, buried holes to achieve this requirement, and thus produced the HDI buried blind hole plate.
For circuits with large redundancy of power pins, the number of matched capacitors can also be calculated according to the number of output pins, and every 5 outputs is matched with a 100nf filter capacitor.
