source:Industry News release time:2022-10-27 Article author:yu Popular:pcb
When designing EMC for printed circuit boards, the layout should be considered first. PCB engineers must coordinate with structural engineers and EMC engineers to take both into account.
First of all, the structure and size of the printed circuit board should be considered, and how to arrange the device. If the devices are widely distributed, the transmission lines between the devices may be long, the printed lines will be long, the impedance will increase, the noise resistance will decrease, and the cost will increase. If the device distribution is too concentrated, the heat dissipation is not good, and the adjacent lines are susceptible to coupling and crosstalk. Therefore, according to the functional unit of the circuit, the overall layout of all components of the circuit. Factors such as electromagnetic compatibility, heat distribution, sensitive and non-sensitive devices, I/O interface, reset circuit and clock system are also taken into account.
In general, the overall layout should comply with the following basic principles:
1, when the circuit board on the high, medium and low speed circuit at the same time, should according to the logic speed of segmentation: decorate fast, medium speed and low speed logic circuit, high speed of the device (fast logic, clock oscillator, etc.) should be placed near the connector range, reduce the antenna effect, and low speed logic and memory, the range should be placed far away from the connector. This is beneficial to the reduction of coimpedance coupling, radiation and cross - interference.
2. In single panel or double panel, if the power cable is long, add the coupling capacitor to the ground every 3000mil, and the value of the capacitor is 10uF+1000pF to filter out high-frequency noise on the power cable.
3, in the single panel and double panel, the filtering capacitor wiring should be filtered by the filtering capacitor filtering, and then to the device pin, so that the power supply voltage is filtered and then the IC power supply, and the IC feedback to the power supply noise will be filtered out by the capacitor first. The position of the decoupling capacitor should be determined according to the actual situation. It is not absolutely placed at the positive pole of the power supply, but may also be placed at the negative pole of the power supply. In principle, the grounding impedance should be minimized.
4, clock line, bus, radio frequency line and other strong radiation signal line away from the interface of the outgoing signal line at least 1000mil, to avoid the interference on the strong radiation signal line coupling to the outgoing signal line outward radiation, crystal, crystal oscillator, relay, switching power supply and other strong radiation device layout should be considered.
5. The input and output signal lines of the filter (filter circuit) cannot be parallel to each other and crossed to avoid direct noise coupling before and after filtering.
Read recommendations:
Six-layer Immersion Gold Board (BGA)
Aluminum substrate (double-sided)
Popular recommended products
Six-layer Immersion Gold Board (BGA)
2021-04-27High frequency PCB
2021-04-27Six-layer Immersion Gold Board (BGA)
2021-04-27High frequency PCB
2021-04-27Single copper base PCB
2021-04-27Aluminum substrate (double-sided)
2021-04-27Six-layer Immersion Gold Board (BGA)
2021-05-27Network communication board (sixth floor)
2021-04-29Six-layer Immersion Gold Board (BGA)
2021-05-24High frequency PCB
2021-04-27Six-layer Immersion Gold Board (BGA)
2021-05-27Six-layer Immersion Gold Board (BGA)
2021-04-27Six-layer Immersion Gold Board (BGA)
2021-05-24Mobile phone template (six layers)
2021-04-27Display board (six layers)
2021-04-27Six-layer Immersion Gold Board (BGA)
2021-04-27High frequency PCB
2021-04-27Six-layer Immersion Gold Board (BGA)
2021-05-27Computer card board (four layers)
2021-04-25Six-layer Immersion Gold Board (BGA)
2021-05-27Laminate copper-based PCB after 4L (sample)
2021-04-27Silver oil perforated plate (double-sided)
2021-04-27Single-sided double-layer AL base PCB
2021-04-27Six-layer Immersion Gold Board (BGA)
2021-04-26SMT stickers
2021-05-27Six-layer Immersion Gold Board (BGA)
2021-04-26SMT stickers
2021-05-27DIP plugin
2021-05-27DIP plugin
2021-05-27Six-layer Immersion Gold Board (BGA)
2021-04-26Mobile phone board
2021-05-27Mobile phone board
2021-04-27Six-layer Immersion Gold Board (BGA)
2021-04-26Six-layer Immersion Gold Board (BGA)
2021-04-26Related Information
The relationship between PCB safety distance and voltage
2024-04-22SMT surface mount processing.Hybrid circuit board PCB
2024-04-15PCB enterprises should pay attention to SMT matters.Electronic components PCB
2024-04-03PCB - the core building block of electronic products.Automotive Electronics PCB
2024-03-25PCB - the bridge and link of the electronic world
2024-03-18How to define high-frequency and high-precision circuit boards.Industrial Electronics PCB
2024-03-11USB PCB interface layout and wiring requirements
2024-01-22Electrolytic capacitor PCB.Steps for using PCB pins
2024-01-15Automotive ElectronicWhat aspects should be considered when processing and manufacturing PCB boards?
2024-01-08Electrolytic capaciWhat is the difference between a gold-plated circuit board and a gold-plated one?
2023-12-25When grinding PCB boards, attention should be paid to.Oscillator (belonging to crystal) PCB
2023-12-18Industrial Electronics PCB!What precautions should be taken when copying and grinding PCB boards
2023-12-11Do you know who is more suitable for LED direct display, regarding the difference between PCB board
2023-12-05Aluminum electrolytic capacitor PCB.What are the standards for selecting PCB boards
2023-11-27Surface Mount Technology (SMT) Phase PCB
2023-11-20Oscillator (belonging to crystal) PCB.The main functions of PCB board
2023-11-13What is the difference between RO filter and PCB filter
2023-11-06Method for determining blind hole PCB board
2023-11-01Electronic Manufacturing Services PCB!What are the effects of PCB board color on performance?
2023-10-23Introduction to the Manufacturing Steps and Requirements of PCBA Test Stand
2023-10-16PCB version maturity stage.AOI circuit board price
2023-09-25How to maintain a PCB circuit board
2023-09-19Development Trend of Printed Circuit Board.Zener diode PCB Vendor
2023-09-14Common problems and cause analysis of PCB circuit board sampling.Zener diode PCB price
2023-09-08What are the issues that need to be understood in PCB circuit board design?IGBT module PCB factory
2023-09-08How to reduce the risk of bending and deformation in PCB circuit board production?Inverter PCB Produ
2023-08-16What are the three main factors that constitute welding defects in PCB circuit boards?Multilayer PCB
2023-08-16The structure of a glass teapot.LCD Module PCB factory
2023-08-11Glass teapot.Inverter PCB Processing
2023-08-11PCB online debugging
2023-08-08