1.How to choose PCB material? Select the PCB material must meet the balance point between design requirements,the production and cost.The design requirements include electrical and institutions.For example, now widely used material FR4, dielectric loss have a great impact on signal attenuation at some frequency,so it is not suitable.For electricity,please note that whether dielectric constant and dielectric loss is suitable in the designed frequency. 2.How to avoid high-frequency interference? Avoid high-frequency interference is to minimize the interference of high frequency electromagnetic signal,that is,also called crosstalk (Crosstalk). 3.In high-speed design,how to solve signal integrity problem? Signal integrity is usually impedance matching problem.The factors affect impedance matching include signal source and output impEDAnce, traces impedance,characteristics of the load sidetraces and topology architecture. 4.How to achieve the differential wiring? Differentia

Resistance as a basic electronic components, widely used in a variety of circuits, generally we also think resistance is the simplest electronic components.In addition to power, there is no excessive stress.If today I say this small resistance, many senior electrical engineers are not really know how to use,do you believe it? In the selection of resistance,if avoided high-frequency circuit special application, generally we only consider the power of resistance.for the average engineer,As long as select the appropriate power by the current that flow through the resistor,then can be counted as qualified. If take into account the instantaneous power, it can be counted as a good engineer. But be able to properly use the resistance, only two things were not enough,pleaes read the following text then you will understand. Look at a simple circuit diagram,by the current flowing through the sample LED lights from sampling resistor R1 and R2,then adjust PWM output,to ensure the LED curren

For high-frequency PCB board,the common interference is power supply noise.Through systematic analysis of power supply noise characteristics and causes inhigh-frequency PCB board,combined with engineering applications,combined with engineering application,we think of some very effective and simple solution ways. Power supply noise analysis:the power supply noise is generated  by itself or interference induction.Its interference in the following aspects: 1:Distributed noises caused by power supply impedance. 2:The common mode field  interference 3:Differential mode field interference 4:Interference between lines 5:Power line coupling Measures to eliminate power supply noise interference: 1:Note the hole on board. 2:Cnnecting line needs sufficient erdung 3:Place power supply noise filter 4:Power Isolation Transformer 5:Power Regulator 6:Wiring 7:Separate analog and digital power supply 8:Avoid power overlap between different layers 9:Isolation sensitive

1. Generating Drill Files To create a Gerber file in Eagle, you should run the drillcfg command first: File -->Run ULP -->  the pop-up "Drill Configuration" dialog box and click the "OK" button to generate the corresponding drill configuration file. 2. Generating Gerber Files Open the .brd file, and then  the "File" menu to open the "CAM Processor" dialog box. In the "CAM Processor" dialog box, select "File" -> "Open" -> "Job ..." command, open the "Open CAM Job" dialog box, select the "excellentone.cam" and click "Open" button. After loading it, click the "Process Job" command to generate the corresponding drill file: In the "CAM Processor" dialog box, select "File" -> "Open" -> "Job ..." command, open the "Open CAM Job" dialog box, select one of the "gerb274x.c