Single sided pcb design
PCB printed circuit board design and manufacture of electronic products is an important link, with the rapid development of electronic technology, PCB density increasing, the single sided pcb design is good or bad anti-interference ability influence. If design not reasonable cause electromagnetic interference, so that the circuit performance is affected, even not work.
Electromagnetic interference
Parallel wire exists between the effect of inductance, resistance effect, electrical effect, electromagnetic effect. One wire of current change will inevitably affect the other wire, thereby generating interference. Printed circuit board printed wiring board, connecting wire and even components lead may be transmitting or receiving signal interference antenna. The high frequency circuit in PCB design cannot be ignored. Circuit magnetic element, such as a loudspeaker, an electromagnet, permanent magnet meter and the constant magnetic field and a transformer, relay, magnetic field generated mutations, on the printed circuit board also can produce an effect.
Double sided pcb board
Double sided pcb board can be avoided, but in the design of printed circuit board can take some measures to suppress interference intensity, improve the anti-interference ability of the circuit itself, to avoid or reduce interference. Generally low level, high impedance side conductor susceptible to interference, wiring should be as short as possible: input, output wires should try to avoid the adjacent parallel lines, preferably in the ground wire, so as to avoid feedback coupling of double sided pcb board. Parallel line effect and proportional length, according to the signal routing in order to avoid detour interludes, these will keep away from the interference source, as far as possible from the power line. Printed circuit board the annular conductors equivalent single turn coil or antenna, the antenna effect enhancement effect of inductance and. Wiring is avoided as much as possible into the annular area. In printed circuit board in the contactor, relay, buttons and other components, operation will produce bigger spark discharge, must use RC circuit to absorb and discharge current. General R of 1 ～ 2K, C from 2.2 ～ 4.7 μ F.CMOS circuit input impedance is very high, and is susceptible to inductive, so when in use to no end to be grounded or connected to the positive power supply. Printed circuit board of electronic products is the most basic components, printed circuit board of the interference suppression is a skill very strong job, at the same time, also need a large number of accumulated experience. As long as we follow some rules in the design, pay attention to experience and technology accumulation and summarization, must be able to design the excellent properties of PCB plate.
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