Keyword: circuit PCB, PCB design
(1). In general, the power cord and ground wiring in the first place, to ensure that the electrical performance of the circuit board. Within the scope of the condition allows, try to widen the power supply, ground wire width, it is best to ground wide than the power cord, their relationship is: ground > power > signal lines, signal lines usually wide: 0.2 ~ 0.3 mm, the smallest width up to 0.05 ~ 0.07 mm, the power cord usually is 1.2 ~ 2.5 mm. Available for digital circuit PCB width of ground wire to form a loop, which constitute a counterpoise to use (analog circuits is can't use)
(2). Prior to the more strict line wiring (such as high frequency line), the input and output side edges should avoid adjacent parallel, lest produce reflection interference. Should add ground isolation when necessary, two adjacent layers of wiring to perpendicular to each other, parallel prone to stray coupling.
(3). Enclosure grounding, Oscillator clock line will try to short, and cannot be attracted all over the place. Clock oscillation circuit, special high speed logic circuit below part to increase the area of land, and other signal lines should not be, so that the electric field around close to zero;
(4). As far as possible use 45 o line wiring, do not use 90 o line, to reduce the high frequency signal of radiation; (demanding with double arc line)
(5). Any signal lines do not form a loop, such as inevitable, the loop should be small; Signal lines of the hole to as little as possible
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