Figure 26 shows an application in which the TCA9554 can be used.
1. The SCL and SDA pins must be tied directly to VCC because if SCL and SDA are tied to an auxiliary power supply that can be powered on while VCC is powered off, then the supply current, ICC, will increase as a result.
2. Device address is configured as 0100000 for this example.
3. P0, P2, and P3 are configured as outputs.
4. P1, P4, and P5 are configured as inputs.
5. P6 and P7 are not used and have internal 100-kΩ pullup resistors to protect them from floating.