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Original question:

TPS62810-Q1: Cff selection, TPS62810-Q1 EVM circuit suggest 22pf but the datasheet suggest 10pF which one should we follow...

TPS62810-Q1: input capacitor selection

PYTsai
Genius 11475 points
Part Number: TPS62810-Q1

Hi 

the datasheet suggest 22uF is good enough. However the TPS62810-Q1 EVM use 100uF + 22uF + 10uF + 2.2uF + 470pF for the input capacitor. 

May i know why EVM use 5 pcs of capacitor for the input voltage, and how do i decide my input capacitor ?  

  • 0
    TI__Genius 17291 points

    Hi,

    Table 7.3 suggested the minimum value of the input cap. and input cap value should be inside specification. EVM is designed with different values of the capacitor to reduce the input noise in the device. But if the input doesn't have a noise problem you can use 22uF. Input cap value can be chosen according to the application.

    Best regards,

    Tanvee  

  • 0
    TI__Intellectual 1525 points

    Hi,

    the 100µF capacitor is to avoid damaging the device when connecting the EVM to a switched on power supply using long leads, which can lead to voltage spikes due to the cable inductance and contact bouncing. You can ignore it for your application.

    The other capacitors are selected to achieve best possible results during EMI testing.
    For most applications, the recommended 22µF is sufficient, some applications benefit from an additional 1nF to 100nF capacitor close to the input of the device - but this is strongly dependent on the layout and the overall system design.