TCA9539-Q1: TCA9539QPWRQ1 VOH of IO @3.3V and equivalent internal structure of IO

1. Use the 3.0 V value; this is the worst case of a 3.3 V ± 0.3 V supply. If you think your supply has better tolerances, you can use linear interpolation; see [FAQ] What method is best used for estimating specification values between those given in the datasheet?

2. The drive strength is higher for higher supply voltages. Also see [FAQ] What is the output voltage (VOH or VOL) when the output current is X or the supply voltage is Y?

Hi Jingru,

Jingru Han said:

1. What is the voltage of VOH if the voltage of VCC is 3.3V?

We do not spec VOH for VCC = 3.3V in this datasheet. We can estimate the min value to be somewhere between the 3.0 V and 3.6 V specifications. It might be beneficial to look at the FAQ Clemens provided in his answer below. 

Jingru Han said:

2. In the datasheet, when VCC is 3V, VOH is 2.6V @8mA; when VCC is 2.3V, VOH is 1.8V @8mA;. So can I assume  there is a equal pull-up resistor as equivalent internal structure of IO in the chip?

P-port output voltage varies with supply voltage. The driver output is push-pull design and not open-drain. Clemens note and FAQ that he tagged is also beneficial to answering your question here.

Regards,

Tyler