PCA9545ADGVRG4

PCA9545A is a bidirectional translating multiplexer and an advanced I2C-bus controller from NXP Semiconductors. It is designed for applications where multiple interrupt inputs and wake-up signals must be monitored, or to provide an interface for multiple downstream I2C-buses. PCA9545A is the successor to the PCA9545, adding features and improved performance.

The PCA9545A is configured and controlled via an I2C-bus interface. The multiplexer can have up to four downstream devices, which are addressed by the inputs on pins I0 to I3. The devices connected to the multiplexer in each direction must share a common ground. The I2C bus interface is bidirectional and can achieve data transfers speeds up to 400 kbit/s.

This device is designed for applications that require rerouting of communications signals; applications such as power management, Audio/Video control systems and instrumentation systems. It is especially useful in high density systems, where power management and routing of signals is a challenge. The PCA9545A offers system designers a great tool to quickly and easily route signals in their systems.

PCA9545A is available in both Mini-DB and standard packages. It is rated for operation between -40 °C to 85 °C. It features built-in glitch filters on all of its I/O pins and its I2C interface is powered from a 3.3V or 5V external supply.

In terms of its working principle, the PCA9545A multiplexer operates as an I2C slave device on the upstream I2C bus. The multiplexer has four downstream bus segments on its ports D0, D1, D2 and D3. After receiving the appropriate communication address from the upstream controller, the multiplexer will allow communication signals from the upstream controller to the appropriate downstream bus segment. The four downstream bus segments can be enabled or disabled by the use of the enable/disable signal (E/D) and the selection pins I0 - I3.

The PCA9545A multiplexer can be used to reduce the number of interrupts needed to be processed as it can handle up to four distinct interrupt sources. The multiplexer provides an enable signal, E/D, that can be used to power down any unused channels. This reduces power consumption and waste. The device also features built-in glitch filters on all its I/O pins to reduce the possibility of false triggers.

In summary, the PCA9545A is an ideal device for applications where multiple interrupt inputs and wake-up signals must be monitored and/or where an interface for multiple downstream I2C-buses is needed. It is capable of routing communications signals quickly and reliably, consuming minimal power and offering built-in glitch filters for enhanced signal integrity.