The output terminals of high-speed CMOS circuits have considerable load capacity, that is, quite large output value. If the output end of a gate is led to the input terminal with quite high input impedance through a very long line, the reflection problem
The power circuit and control signal circuit components need to be connected to different ground layers, which are generally connected through a single point.
Attention should be paid to the wiring of signal lines under magnetic beads, between pads and those that may come into contact with magnetic beads. Some magnetic beads conduct electricity quite well and may produce unexpected conductive paths.
Adjacent to these connection points, a pad or mounting hole for mounting is placed between the case ground and the circuit ground. These ground connections can be cut open with a blade to keep the circuit open, or a jump with a magnetic bead/high frequenc
Power part and control part separate layout, power circuit is generally large voltage, large current, high power circuit, relatively large interference. And the control circuit is low voltage, if the control part to the power part, the control part is ver
For RF-PCB wiring, each adjacent signal line (including adjacent planes) is formed to follow the basic principle of double line features (this will be explained later).
a simple and applicable method is to first lay the ground wire, then place key signals such as high speed clock signals or sensitive circuits near their ground loops, and finally route other circuits. The layout of the signal line is best arranged accordi
In addition, unused gate circuits are often used for design improvements later, and they may be converted into circuits.
It costs some money to test a friendly PCB design, however, it costs more to test a difficult PCB design. Testing itself has a cost, and the cost of testing increases with the increase of the number of tests; From online testing to functional testing and
Many companies have started to set up a circuit board pricing program on their Web sites, with rules that allow customers to freely calculate prices. People who do not understand PCB can also easily calculate the price of PCB.
At this point, scanning acoustic microscope shows its special advantage in nondestructive detection of multilayer high density PCB. And the general obvious explosion plate is only through the visual appearance can be detected.
For some parts that cannot be inspected by appearance, as well as the through hole inside the PCB and other internal defects, X-ray fluoroscopy system has to be used for inspection.
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