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Wi-Fi Combo Forum Discussions

jepac_2686711
Level 1
Level 1

Hi

As per data-sheet CYW94343 can work with a 24 MHz external TCXO as reference clock.

The BCM94343WWCD1_1 kit uses a 26 MHz crystal. What are the NVM changes needed to support an external 24 MHz TCXO?

Thanks,

JP

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1 Solution
Anonymous
Not applicable

Hi JP,

The wlan radios will operate from a wide range of clock frequencies as defined in the chip datasheet.   That said, the datasheet numbers are defined for operating at 26MHz *with* the defined evaluation board layout *and* defined critical components, which includes the xtal.

In principle, the only change you would need to make would be to the nvram file and change the parameter value for xtalfreq (default value  xtalfreq=26000). 

It would then be necessary to use a xtal of the same type as that defined on the eval board otherwise the rf performance will be severely degraded (clock accuracy and phase noise are critical).   We would also advise that full rf qualification would be required if any of the nominated critical components, such as xtal, are changed as we cannot guarantee full compliance with IEEE standards/regulatory controls.

Regards

Dave

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1 Reply
Anonymous
Not applicable

Hi JP,

The wlan radios will operate from a wide range of clock frequencies as defined in the chip datasheet.   That said, the datasheet numbers are defined for operating at 26MHz *with* the defined evaluation board layout *and* defined critical components, which includes the xtal.

In principle, the only change you would need to make would be to the nvram file and change the parameter value for xtalfreq (default value  xtalfreq=26000). 

It would then be necessary to use a xtal of the same type as that defined on the eval board otherwise the rf performance will be severely degraded (clock accuracy and phase noise are critical).   We would also advise that full rf qualification would be required if any of the nominated critical components, such as xtal, are changed as we cannot guarantee full compliance with IEEE standards/regulatory controls.

Regards

Dave