I am comparing the data sheet of TCA6416, and TCA9555 and TCA9539.
http://www.ti.com/lit/ds/symlink/tca9539.pdf
http://www.ti.com/lit/ds/symlink/tca9539.pdf
http://www.ti.com/lit/ds/symlink/tca9555.pdf
I am comparing delta Icc and I/O structure of these three devices.
TCA9555 has pull-up resistance of 100Kohm.
However, TCA6416 and TCA9539 do not have pull-up resistance.
delta Icc of TCA9539 is 1.5mA although delta Icc of TCA6416 are 25/60uA.
The I/O structure of these two devices looks almost the same.
Regards, Hidetaka.