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Decoupling capacitors rayout of DS90CR217

Tsuguhiko Asai
Expert 1260 points
Other Parts Discussed in Thread: DS90CR217, DS90CR216

Dear All,

Let me ask the following question about Decoupling capasitors of DS90CR217.
According to Figure14 of the data sheet, a capacitor of more large value (0.1μF) than the others is located near the IC.
Generally, should a capacitor of more small value (0.001μF) than the others be located near the IC?

Best Regards,
Tsuguhiko Asai

  • 0
    TI__Expert 3050 points
    Hi Asai-san,

    Figure 14 shows that it is desirable to have an array of capacitors of different value next to the device to filter power supply noise. These capacitors help to filter high frequency noise and should be placed close to the device.

    Bulk capacitors, 4.7uF or more, should be placed closer to the entry point to the power plane or power distribution network.


    Mike Wolfe
    DPS APPS / SVA
  • 0 in reply to Mike Wolfe
    Expert 1260 points

    DS90CR217_Image.pdfDear Mike-San

    Thank you very much for your kind answer.

    I understand from your other evaluation board (or as my general understanding),

    smaller cap should be placed to closer position to IC.

    (Please refer to attached pdf file.)

    (For this case, 0.001uF should be closer rather than 0.01uF/0.1uF)

    Do you have any specific requirement for DS90CR217?

    Best Regards

    Tsuguhiko Asai

  • 0 in reply to Tsuguhiko Asai
    TI__Expert 3050 points
    Hi Asai-san,

    We do not have any specific requirements for the DS90CR216 capacitor placement order. In general, it is good to keep the supply noise as low as possible, but it should be at least less than 100mVpp. Placing the capacitors as close to the pins as possible is more important than the order.

    Mike Wolfe
    DPS APPS / SVA