PCA9541AD/01,118

The PCA9541AD/01,118 from NXP Semiconductors is a 2-to-1 I2C-bus master selector, engineered for high-reliability dual master I2C-bus systems. This component is crucial for applications where system operation must continue even if one master fails or is removed for maintenance. It allows two masters, such as a primary and a backup, to connect to the same downstream I2C-bus slave devices.

This device supports an operating voltage range of 2.3V to 5.5V and utilizes the I2C and SMBus interfaces. It is available in a 16-SOIC package and is designed for surface mount applications. The PCA9541AD/01,118 includes interrupt logic and reset capabilities, providing indications of bus control and facilitating bus recovery sequences.

The selector isolates failed masters from the system, ensuring uninterrupted communication between the online master and slave devices. It also features a bus sensor to detect non-idle bus conditions during channel switches, generating an interrupt if necessary. The pass gates allow for different bus voltages (1.8V, 2.5V, or 3.3V) to communicate with 5V devices without additional protection, though external pull-up resistors are required on all channels.