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VCC2 capacitor of UCC5390

Other Parts Discussed in Thread: UCC5390

We have questions about VCC2 capacitor of UCC5390.

In dataseet p.37 11.2.3.2 "Selecting a VCC2 Capacitor",

A 50-V, 10-μF MLCC and a 50-V, 0.22-μF MLCC are selected for the CVCC2 capacitor. 

Must we keep the value of voltage and capacitance(50-V, 10-μF MLCC and a 50-V, 0.22-μF MLCC)?

Is this value an example?

Can we change the voltage and capacitance value when we select the VCC2 capacitor?

Our customer have a trouble obtaining ceramic capacitor of 50V-10µF and 50V-0.22µF.

So, our customer thinks that they want to change the value of VCC2 capacitor(voltage and capacitance) according to the secondary condition and spec of MOSFET or IGBT.

Are capacitance and voltage mandatory?

Can we increase or decrease value?

Best regares,

Takahiro Nishizawa

  • Hello Nishizawa-san,

    The capacitor values in section 11.2.3.1 and 11.2.3.2 are general recommendations which your customer can change to match their design requirements. We specify 50-V capacitors to account for any capacitance derating that occurs when VCC2 is applied. Make sure to check the capacitor's datasheet to understand its derating curve and size the voltage and capacitance ratings accordingly.

    Generally, we specify a range of 220nF to 10uF for device biasing (VCC2) and an additional 100-nF capacitor in parallel for high-frequency filtering.

    What kind of voltages are they putting across VCC2-VEE2? Can you describe the application?

    regards,
    Mateo
  • Hello Nishizawa-san,

    It has been some time since we last heard from you and we are going to assume that we resolved your question.

    I'm going to close this thread and mark it resolved unless you have additional questions.

    Regards,
    Mateo