I have a question regarding the pins VDDLDOD, VDDLDOA and EXTON.

As stated in the DW1000 datasheet section 7.1 the pins VDDLDOD and VDDLDOA can be supplied by 3V3 or optionally by 1V8.

However, I would like to know if it could have negative effects in terms of performance when both pins are supplied with 3V3 instead of 1V8 ?

In addition, I would like to know if VDDLDOD and VDDLDOA can be supplied independently by two different LDO regulators or if their power supply need to be somehow connected in order to be exactly the same ?

Moreover, I already saw there was a discussion about the EXTON pin in case it is not used to control a DCDC converter:

It was recommended in the thread above to leave the EXTON pin floating if it is not used. Can someone confirm that this is the appropriate practice in case the EXTON pin is not used ?

Kind regards

If you don’t use the EXTON , you can leave it floating.

With regards not using the LDO, you could connect them to the 3.3V
The VDDLDOA and VDDLDOD pins on the chip supply power to the on-chip linear regulators for the 1.4 V on-chip analog circuits and 1.2 V on-chip digital circuits. See datasheet fig 35 Power Supply Connections.

It is entirely possible to connect these pins directly to the 3.3 V supply, however in that case the on-chip linear regulators must drop 3.3 V down to 1.4 V and 1.2 V respectively which has an associated power loss due to heating.

A better solution is to use an off-chip efficient DC/DC converter to drop the 3.3 V to something like 1.8 V or 1.6 V which means the on-chip regulators only need to drop a few hundred mV.
And what LDOs you also find in the datasheet section 8.2

Happy New Year

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thank you very much for your advice.

Just to clarify further, if using 1.8V for VDDLDOD and VDDLDOA, is it necessary to use EXTON also. I can power with 1.8V there and still leave EXTON floating?

Hi @bstarbuck
yes you can leave EXTON unconnected.


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