ZHCSNJ5E October 2005 – March 2021 PCA9545A
PRODUCTION DATA
Applications of the PCA9545A will contain an I2C (or SMBus) master device and up to four I2C slave devices. The downstream channels are ideally used to resolve I2C slave address conflicts. For example, if four identical digital temperature sensors are needed in the application, one sensor can be connected at each channel: 0, 1, 2, and 3. When the temperature at a specific location needs to be read, the appropriate channel can be enabled and all other channels switched off, the data can be retrieved, and the I2C master can move on and read the next channel.
In an application where the I2C bus will contain many additional slave devices that do not result in I2C slave address conflicts, these slave devices can be connected to any desired channel to distribute the total bus capacitance across multiple channels. If multiple switches will be enabled simultaneously, additional design requirements must be considered (See Design Requirements and Detailed Design Procedure).