When MCU I/O port is OPEN DRAIN output, is it allowed to supply higher voltage for its external pull-up resistor than IC supply voltage?
Sonix IC's open drain are pseudo open drain, external pull-up resistor voltage should
be less than or equal to MCU's VDD, the main purpose is to apply in a number of parallel
connection output bus (eg I2C), or a conversion for voltage lower than VDD Interface
voltage level. Users can add transistors to solve this problem.