How to make a good DC power supply on PCB board
Everyone knows that to make a DC power supply PCB board is to turn the designed DC power supply schematic diagram of the DC power supply PCB board into a real DC power supply PCB DC power supply circuit board. Please do not underestimate this process. There are many DC power supply principles upstream. Something that works is difficult to achieve in engineering, or something that others can achieve, but others cannot.
Therefore, it is not difficult to make a DC power supply PCB board, but it is not an easy task to make a DC power supply PCB board. The two major difficulties in the field of microelectronics are the processing of high-frequency signals and weak signals. In this regard, DC power supply The level of PCB production is especially important. The same DC power supply principle and DC power supply PCB board design, the same DC power supply components, and the DC power supply PCB produced by different people have different results, so how can we make a good DC power supply? What about the power supply PCB board?
To clarify the design goal of the DC power supply PCB board. To accept a DC power supply PCB board design task, we must first clarify its DC power supply PCB board design goal, whether it is an ordinary DC power supply PCB board, high frequency DC power supply PCB board, small signal processing DC power supply PCB board or If the DC power supply PCB board with both high frequency and small signal processing is an ordinary DC power supply PCB board.
As long as the layout and wiring are reasonable and tidy, and the mechanical dimensions are accurate, if there are medium load lines and long lines, certain methods must be used to deal with them to reduce the load. For 40MHz signal lines, special consideration should be given to these signal lines, such as crosstalk between lines. If the frequency is higher, the length of the wiring will be more strict.
According to the network theory of distributed parameters, the interaction between the high-speed DC power supply circuit and its wiring is a decisive factor. The DC power supply PCB board design of the DC power supply system cannot be ignored. As the transmission speed of the gate increases, the opposition on the signal line will increase accordingly. The crosstalk between adjacent signal lines will increase in proportion to the power consumption and heat dissipation of the usual high-speed DC power supply circuits.
Enough attention should be paid to high-speed DC power supply PCBs. When there are millivolt or even microvolt-level weak signals on the board, special care is required for these signal lines. Small signals are too weak and are easily interfered by other strong signals. Measures are often necessary, otherwise it will greatly reduce the signal-to-noise ratio so that the useful signal is submerged by noise and cannot be effectively extracted. The commissioning of the board should also consider the physical location of the test point during the design of the DC power supply PCB board.
Isolation factors cannot be ignored because some small signals and high-frequency signals cannot be directly added to the probe for measurement. In addition, other related factors such as the number of layers of the board and the mechanical strength of the package shape board with DC power components should be considered. Before making a DC power supply PCB board, we have to make the DC power supply PCB board design goals for the DC power supply PCB board design.
Understand the functions of the DC power components used and the requirements for layout and wiring. We know that some special DC power components have special requirements during layout and layout, such as the analog signal amplifiers used by LOTI and APH. The small signal part should be kept away from the power device as far as possible. The small signal amplifying part of the OTI board is also specially equipped with a shielding cover to shield the stray electromagnetic interference. The GLINK chip used on the NTOI board uses ECL technology. The power consumption is severe and the heat dissipation problem is Special considerations must be made in the layout if natural heat dissipation is used.
Place the GLINK chip in a place where the air circulation is relatively smooth and the heat emitted cannot have a big impact on other chips. If the board is equipped with speakers or other high-power devices, it may cause serious pollution to the power supply. This should also be caused. Enough attention.