Tool/software:
Dear
Chang from LDO 3.3V to DC-DC LMQ66410 3.3V power supply resulted in abnormal MCU serial communication, there is an MCU serial communication abnormality with MCU TX/RX: 115200
when using LM166410 with multiple sections and small steel pipes; The inductor uses shielded inductor LPS3015-472. After changing the DC-DC converter, the ripple increases and when placed in a small steel pipe, the inductance value changes or the operation becomes unstable. Multiple devices with 485 bus parallel connection may experience ripple superposition (because the same firmware placed in a small steel pipe will not occur in a single section)
The measured parallel ripple of multiple sections reaches 390mV, while the actual microcontroller can tolerate fluctuations of 300MV and a DCDC frequency of 2.2Mhz
