In electronic equipment, grounding is a general conventional method for suppressing noise. so it becomes extremely important to Cloning Electronic PCB Card Grounding Scheme to interference the noise effect;
If grounding and shielding can be used in combination, it can solve most noise problems. The grounding structure of electronic PCB card is roughly divided into: system ground, shielded ground, and digital ground And power supply analog ground, etc., the following points should be noted in the ground design:
A. In low-frequency circuits, the operating frequency of the signal is less than 1MHz. The inductance between its wiring and components is small, and the circulating current formed by the grounding circuit has a greater impact on noise. Therefore, one-point grounding should be used. When the working frequency of the signal is greater than 10 MHz, the impedance of the ground wire becomes very large.
At this time, the impedance of the ground wire should be reduced as much as possible, and multiple points of ground should be used as close as possible. When the working frequency is between 1 to 10 Mhz, if one-point grounding is adopted, the length of the ground wire should not exceed 1/20 of the wavelength, otherwise the multi-point grounding method should be used.
B. If there are high-speed logic circuits and linear analog circuits on the printed circuit board reverse engineering, they should be separated as much as possible, and the ground wires of the two should not be mixed, and they should be connected to the power supply ground wires. Try to increase the ground area of the circuit.
C. Try to thicken the ground wire
D. The ground wire constitutes an infinite cycle, because there are many integrated circuit components on the printed circuit board, especially when there are components that consume a lot of power, due to the thickness of the ground wire, a large potential difference will occur, causing resistance The noise capability is reduced, if the ground is formed into a loop, the potential difference will be reduced, and the anti-noise capability of the electronic equipment will be improved
