1.Ground loop area: keeping the signal path and its ground return line close together will help minimize the ground.
2.Generally, the clock circuit is arranged on the PCB board to accept the center position or a well-grounded position so that the clock is as close as possible to the microprocessor and keep the lead as short as possible while the quartz crystal oscillates only having housing ground.
3.To further enhance the reliability of the clock circuit, increase the area of the ground under the crystal oscillator to avoid cloth other signal lines. as short as possible while the quartz crystal oscillates only having housing ground.
4.The principle of component layout is to divide the analog circuit part from the digital circuit, divide the high-speed circuit and the low-speed circuit, divide the high-power circuit and the small-signal circuit, divide the noise element and the non-noise element, and minimize the distance between the components Lead, so that the coupling between each other can achieve the smallest.