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zltmsmile
Aug 31, 2021
In Welcome to the Forum
Today we will introduce the components of pcb online china and take you to explore the basic components of PCB in depth. 1) Components Components are various devices used to complete circuit functions. Each component contains several pins, and electrical signals are introduced into the component through the pins for processing, so as to complete the corresponding function. The pins have the function of fixing components. The components on the circuit board include integrated circuit chips, discrete components (such as resistors, capacitors, etc.), and connectors that provide circuit input/output and circuit board power ports. Some circuit boards also have devices for indication (such as digital Tubes, light-emitting diodes, etc.). Components are used to complete the core device of circuit functions and are an indispensable and important part of electronic products. Each component contains multiple pins, and the component will introduce electrical signals into the component through the pins for processing, thereby completing the corresponding function. The components on the circuit board include integrated circuit chips, discrete components (such as resistors, capacitors, etc.), and connectors that provide circuit input/output and circuit board power ports. 2) Copper foil On the circuit board, it can be expressed in various forms, such as conductors, pads, vias, and copper coatings. Their respective functions are as follows. (1) Wire: used to connect the pins of each component on the circuit board to complete the electrical signal connection between each component. (2) Vias: In multilayer circuit boards, vias appear to complete the establishment of electrical connections. They are used to connect the copper foil connected in the middle layer, and the upper and lower surfaces of the through holes are made into ordinary pad shapes, which can be directly connected with the upper and lower wires. (3) Mounting hole: used to fix the printed circuit board. (4) Pad: used to fix the component on the circuit board. It is also an integral part of the path of electrical signals entering the component. The mounting holes for mounting the entire circuit board sometimes appear in the form of pads. (5) Connector: used to connect components between circuit boards. (6) Filling. By placing copper in the manual grounding network, the impedance can be effectively reduced. (7) Electrical boundary: used to determine the size of the circuit board. All components on the circuit board must not exceed the boundary. (8) Printed material: It is made of insulating material and used to support the entire circuit. This is the basic element of a common fast PCB manufacturing, I hope to provide you with some help
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zltmsmile
Jul 14, 2021
In Welcome to the Forum
Crosstalk means that a changing signal (such as a step signal) propagates from A to B along the transmission line, and a coupled signal will be generated on the transmission line CD; once the changed signal ends, that is, when the signal returns to a stable DC level, the coupled signal does not exist. . Therefore, crosstalk only occurs in the process of signal hopping, and the faster the signal edge changes (conversion rate), the greater the crosstalk generated. So, what are the crosstalk analysis modes in pcba manufacturer design? The electromagnetic field coupled in space can be extracted as a collection of countless coupling capacitors and coupling inductances. The crosstalk signal generated by the coupling capacitor can be divided into forward crosstalk and reverse crosstalk Sc on the victim network. These two signals have the same polarity; The crosstalk signal generated by the inductance is also divided into forward crosstalk and reverse crosstalk SL, and these two signals have opposite polarities. The forward crosstalk and reverse crosstalk caused by the coupled inductance and capacitance exist at the same time, and the magnitudes are almost equal. In this way, the forward crosstalk signals on the victim network cancel each other due to opposite polarities, and the reverse crosstalk polarities are the same, and the superposition is enhanced. The modes of crosstalk analysis usually include default mode, tri-state mode and worst-case mode. In the default mode, the offending network driver is driven by the flip signal, and the victim network driver maintains the initial state, and then the crosstalk value is calculated. This method is more effective for crosstalk analysis of unidirectional signals. The tri-state mode means that the driver of the offending network is driven by a flip signal, and the tri-state terminal of the victim network is set to a high-impedance state to detect the size of the crosstalk. This method is more effective for two-way or complex topology networks. The worst-case mode is to keep the driver of the victim network in the initial state, and the simulator calculates the sum of the crosstalk of all the default infringement networks to each victim network. This method generally only analyzes individual critical networks. The above are the three modes of crosstalk analysis in quick turn PCB design. Have you mastered them?
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