CA9545MR is a low-voltage, 4-channel bidirectional I²C/SMBus switch featuring level translation, interrupt management, and an active-low RESET input. It allows a single I²C/SMBus master to access any individual channel or any combination of four downstream buses, enabling flexible segmentation and isolation of I²C devices in complex systems.

An 8-bit control register provides channel selection, while the RESET pin allows the device to recover from stuck-bus conditions by deselecting all channels and resetting the I²C state machine. The device integrates four separate interrupt inputs (INT0–INT3) and one combined interrupt output (INT) for upstream notification. Each channel can operate at different logic levels (1.8 V, 2.5 V, 3.3 V, 5.0 V) using appropriate pull-up resistors.

Supporting Fast Mode+ speeds up to 1 MHz, hot insertion, noise filtering on SCL/SDA lines, and 5.5 V-tolerant inputs, the CA9545MR is well suited for server, notebook and telecom applications.