Hardware Development Guide of Module Product
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52
MF206A
components connected to that supply, introducing the noise floor at the burst base frequency. For this reason
while a voltage drop of 300-400 mV may be acceptable from the power loss point of view, the same voltage
drop may not be acceptable from the noise point of view. If your application doesn't have audio interface but
only uses the data feature of the ZTEWelink module, then this noise is not so disturbing and power supply layout
design can be more forgiving.
The PCB traces to the ZTEWelink module and the Bypass capacitor must be wide enough to ensure no
significant voltage drops occur when the 2.5A current peaks are absorbed. This is for the same reason as
previous point. Try to keep this trace as short as possible.
The PCB traces connecting the Switching output to the inductor and the switching diode must be kept as short as
possible by placing the inductor and the diode very close to the power switching IC (only for switching power
supply). This is done in order to reduce the radiated field (noise) at the switching frequency (100-500 kHz
usually).