Hi,
What should I do with the unused LPC4330 RTC pins in my design(VBAT, RTCX1, and RTCX2)?
Should I pull them low, high, or what should I connect them to?
Many thanks,
Murdo.
Hi,
When the RTC is not used, connect VBAT to VDD(REG)(3V3), I would recommend that RTCX1 be grounded since it is an input. RTCX2 is an output, so it can be left open.
Have a great day,
Sol
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Hello Sol,
Thank you for replying so quickly.
In the question and response at https://community.nxp.com/thread/420015 Paul said that connecting VBAT is not required as the RTC is powered by either VDD(REG) or VBAT. I am finding it hard to route the VBAT under the already routed 256-pin BGA, so I am keen to know if it does require 3V3 or if I could leave it floating?
In the datasheet at https://www.nxp.com/docs/en/data-sheet/LPC4350_30_20_10.pdf (page 83, fig 9) it shows the two power rails just diode-Or'd so I wonder if VBAT needs any connection at all.
Kind regards,
Murdo.
Hi,
I strongly suggest that you connect the VBAT to Vdd to avoid current Leakage.
Have a great day,
Sol
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