In PCB design, common design errors not only lead to waste of cost and time, but also affect product reliability and performance. Therefore, when designing PCBs, you need to pay attention to some tips to avoid common design mistakes.
Avoid layout errors
When conducting PCB layout design, comprehensive considerations should be made based on multiple factors such as circuit characteristics, signal transmission requirements, and external environment. For example, the modulator should be placed close to the antenna during layout, and sensitive signal lines should be avoided in the power circuit area. Also pay attention to avoid the following common layout errors:
1. Blocking heat dissipation
When laying out the PCB, attention should be paid to the setting of the heat sink. If the heat sink is blocked, it will cause the device to overheat, affecting product performance and life.
2. The ground wire is too long
If the ground wire is too long, it will lead to higher ground impedance and ground potential difference, which will affect signal transmission.
3. The signal line is too long
If the signal line is too long, it will cause higher crosstalk and loss, reducing the system signal-to-noise ratio.
Correctly select components
In PCB design, correct selection of components is very important. Selecting the appropriate components can improve the reliability and performance of your circuit. For example, high-speed, low-noise devices should be used in high-frequency circuits, while lower-cost, slower devices can be selected in low-frequency circuits. Also note the following points:
1. Avoid using aging components
Aged capacitors and resistors can cause circuit failure and instability.
2. Choose the appropriate component layout
When selecting components, you should also consider the layout of the components. For example, capacitors in a power circuit should be as close to the power chip as possible.
3. Avoid using components of different quality
In PCB layout, components of different brands or qualities should be avoided to ensure circuit consistency and reliability.
Reasonable wiring planning
When conducting PCB routing, standard principles should be followed, including minimizing line noise, maintaining signal integrity, and minimizing crosstalk. Here are some common routing errors:
1. Too many curved traces
Bent traces increase inductance and can increase peak delay and distortion in high-speed signal transmission.
2. Too many branches and forks
Excessive branches and forks will cause signal reflection and crosstalk, reducing the signal-to-noise ratio.
3. Lines exceeding the specified length
Signal integrity is affected when line length exceeds specified limits.
Pay attention to electromagnetic compatibility
In PCB design, electromagnetic compatibility is also an important aspect. The following measures can be taken to avoid electromagnetic compatibility problems:
1. Good status design
A good position design can reduce the impact of electromagnetic behavior on the equipment. Multi-point grounding or buried layer techniques can be used.
2. Reference clock self-isolation
In high-speed lines, reference clock lines should be isolated and separated.
3. Shielding method
Shielding methods can reduce electromagnetic interference and radiation.
In PCB design, layout, component selection, trace planning and electromagnetic compatibility are very important aspects. Follow these tips to avoid common design mistakes and improve product reliability and performance. In future PCB design, we should pay more attention to these aspects and improve the level and efficiency of circuit design.