I2C I/O expander Output retention.

[marcokuysterman]

The PCAL6416 I/O expander has two power domains, i.e. VDD(P) and VDD(I2C). When I remove VDD(I2C) but leave VDD(P) connected to VDD do the output change or is the output data retained?

Thank you in advance!

Marco

[TomasVaverka · Accepted solution]

Hello Marco,

VDD(P) is supply voltage of P0 and P1, so if you remove VDD(I2C) but leave VDD(P) connected to VDD, then the output data will indeed be retained. 

Best regards,

Tomas