Maximum IO Voltage for LPC55S Family

asarau — Fri, 26 May 2023 19:17:55 GMT

I would like to operate the LPC55S6x series with a VCC of 1.8V and I am trying to figure out the maximum input voltage to the GPIO signals.

Unfortunately the LPC55S6x datasheet provides two tables related to the maximum input voltage (VI) on IO pins programmed to provide a digital function, Table 11 and Table 24, that appear to conflict.

Table 24 indicates that the maximum input voltage for a device operating above 1.8V is 3.6V.

Table 11 indicates that the maximum input voltage for a device operating above 1.8V is VDD + 0.5V.

I believe that table 24 is correct, and a 3.3V signal may be driven into the LPC device when operating at 1.8V due to note 2 under table 11 that states: "Maximum/minimum voltage above the maximum operating voltage (see Table 24) ".

May the LPC55S6x operate at 1.8V while having a 3.3V signal driven into the device without damaging it?

Thanks

Re: Maximum IO Voltage for LPC55S Family

ZhangJennie — Tue, 30 May 2023 06:40:43 GMT

Hi asarau

LPC55S6x can't operate at 1.8V with having 3.3V signal driven into the device. This will damage the device.
Table 11 is correct.
Table 24 defines the input voltage range but it must accord with Table 11 as well.

Thanks,

Jun Zhang

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Maximum IO Voltage for LPC55S Family

Re: Maximum IO Voltage for LPC55S Family