Measures to suppress noise are implemented as follows based on the investigation results.
Measures were implemented that focus on the suppression of normal mode noise.
→ Insert an LPF near the power connector. (Measure to suppress noise over all frequencies)
[Example] Inductor: LQH5BPZ4R7NT0 + capacitor: GCM188R71E105KA49
The following methods are effective measures for suppressing the noise of a step-down DC-DC converter.
→ Attach a shield to the circuit substrate. (Measure to suppress noise up to 20 MHz)
→ Insert a common mode choke coil (CMCC) immediately next to the power connector. (Measure to suppress common mode noise at 20 MHz or more)
→ Insert an LPF near the power connector. (Measure to suppress normal mode noise at 20 MHz or more)
*This method can be used together with the above measures to suppress conducted noise.