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PCM1789-Q1: System clock selection

Part Number: PCM1789-Q1

Hi team,

Customer asked how to select system clock frequency.

- 16bit inpu data

- Sampling rate = 48kHz

Q.1) According to Table 3, it looks the higher system clock frequency, the better noise-free shaped bandwidth. Is Drawback the higher power consumption?

Q.2) When fs =48kHz, fsx512, fsx768, fsx1152 are all in same column. Is there no merit to select higher system clock than fsx512 if sampling rate = 48kHz?

Best regards,

  • Hi Fujihara-san,

    1. You are correct, the drawback is higher power consumption.  In addition, there can be difficulty in routing the PCB layout with very high-frequency signals.

    2. There is no benefit to using a higher clock than the 512×fs with fS=48.  The performance with the Filter OSR =8x and modulator OSR = x128.

    Thanks,

    Paul