ab. Once the slave device is ready, it signals the master by releasing SCL, and the master reasserts the clock signal. The slave transmits one byte (one bit per clock) over the SDA line.[translate]
TCA9548 has Vcc =3.3V TCA9555 has Vcc=1.8V Pullup resistors are connected to 1.8V. Yet according to TCA9548 datasheet Vpass(@Vcc=3.3V)=~2V, which is higher than the 1.8V pullup voltage and the Vcc of TCA9555 . Meaning the output voltage may go high...
The SCL/SDA bus voltage levels are dependent on the supply voltage (which may vary between 1.4V and 3.6V). The datasheet states the minimum VIH level is 0.7(V+), meaning that the minimum acceptable voltage level is 70% of the supply voltage. If V+ is 1.4V, the VIH(min) is ...
The pullups have a very significant impact on both the clock line and the data line...but do not directly affect the clock frequency. I2C is an open-drain bus, meaning there is an active pulldown xistor on each of the clock and data lines at every node (Master or Slave) on the bu...