Q&A(FAQ)
What is EMI filter recommended for DC-DC converter?

Fig.1 shows external noise filter which reduce the line conducted noise for DC-DC converter.

Fig.1 Example of noise filter

Table 1. cable list
No. Parts No. Components Note
1 C1 Ceramic capacitor Low impedance
(recommended value: 4.7uF)
2 C2 Electrolytic capacitor Low impedance
(please see instruction manual on catalogue)
3 C3 Ceramic capacitor Low impedance
(recommended value: 4.7uF)
4 C4 Ceramic capacitor Low impedance
(recommended value: 1000pF)
5 L1 Common mode coil High leakage inductance
(recommended: main 14mH, leakage 240uH)

The wiring method, the component's location or some other conditions are effect on line conducted noise. Please evaluate under end-use condition before using.

  • * Please consider about C4. The permeation noise from input to output will be increased by C4.

Technical Product-related Inquires

e-mail:support@cosel.co.jp