Keyword: pcb copy board, pcb , circuit board, pcb board
PCB copy board signal isolation technology pcb board is to make digital or analog signals do not exist when it is sent across the barrier between the sending and receiving end of the current connection. This allows the sending and receiving end outside the ground or reference level of the difference can be up to several thousand volts pcb board, and to prevent possible damage to the signal ground potential difference between the loop current , mainly used in pcb board : 1.System ground noise is relatively large , easy to damage the signal , the signal can be separated to isolate a clean signal subsystem pcb board, the power supply, to ensure reliability of the signal isolation portion , meet the system design requirements. 2.the system voltage difference is very large . pcb board For example, in strong electric circuits, we usually through isolation , the operating voltage to the IC into the allowed operating range. 3.reference level to produce an electrical connection between the operator a safe current path .
By isolating the current control in a safe range. In isolation technology , the designers were isolated according to the different types of signals and isolation requirements, to select a different isolation devices is the key : 4.The first optical isolation device depends on the transmitter pcb board and the receiver to cross the isolation barrier. Main coupler ( Figure 4-18 ) and isolation transceiver IC. Through the optical system to cut off the current , capacitance but also to avoid electrical interference . Such devices are used in digital signals.pcb board 5.analog transformer with transformer coupling electromagnetic induction to transmit and receive signals ( Figure 4-19 ) .
More difficult to make the transformer , it is difficult to precisely control parameters , and usually not made IC, it is not very convenient to use pcb board. But linearized problems forced analog signal isolation using transformers. 6.In order to overcome the inconvenience of using the transformer , engineers use the analog modulated carrier signal cross this barrier. So come up with a capacitor circuit coupled to the modulation signal across the barrier. Role in the isolation barrier on high slew rate can be used as a single capacitance transient voltage pcb board signal barrier devices , developed dual capacitor differential circuit to minimize errors pcb board. Now capacitive barrier technology has been applied in digital and analog isolation device pcb board.
