ZHCSJJ3E July 2009 – April 2019 TCA9555
PRODUCTION DATA.
The TCA9555 features 3 hardware address pins (A0, A1, and A2) to allow the user to program the device's I2C address by pulling each pin to either VCC or GND to signify the bit value in the address. This allows up to 8 TCA9555 to be on the same bus without address conflicts. See the Functional Block Diagram to see the 3 pins. The voltage on the pins must not change while the device is powered up in order to prevent possible I2C glitches as a result of the device address changing during a transmission. All of the pins must be tied either to VCC or GND and cannot be left floating.