DS90UB933-Q1: GPIOS of DS90UB933-Q1 are Drain open?

Hello,

No GPOs on the 933 are not open drain.  The only pins that are open drain are the I2C pins.  However if you look at the PIN FUNCTION table, you should be tying GPO2 to ground through a 40kOhm resistor.

Regards,

Nick