MeiG_SLM550_Hardware Design Manual
MeiG Smart Technology Co., Ltd
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The conducted interference is mainly caused by the voltage drop of VBAT. If the Audio PA is directly
powered by VBAT, it is easier to hear the “zizi” sound at the SPK output. Therefore, it is better to
connect in parallel with the input of the Audio PA in the schematic design. Some large capacitance
capacitors and series magnetic beads.
The conducted interference is also strongly related to TDD and GND. If GND is not handled well, many
high-frequency interference signals will interfere with MIC and Speaker through devices such as bypass
capacitors, so users should ensure good performance of GND during PCB design.
5.2.7 Safety clearance
The outer pads of the module are designed for stamp holes. When making the SMD steel mesh, the
pads need to be expanded to enhance the solder climbing ability. Therefore, there must be a safe
distance between the module pads and other motherboard components. The recommended safe
distance is 3mm. As shown below: