CA9544MR is a low-voltage, 4-channel bidirectional I²C/SMBus switch with integrated level translation and interrupt management. It allows a single I²C/SMBus master to access any one or any combination of four downstream channels, providing flexible bus segmentation in complex digital systems. An 8-bit control register enables channel selection, while the power-on reset function restores normal bus operation by deselecting all channels and resetting the I²C state machine when needed.

The device provides four individual interrupt inputs (INT0–INT3) and a single combined interrupt output (INT) for upstream signaling. Each I²C channel supports different operating voltages — 1.8 V, 2.5 V, 3.3 V or 5.0 V — using appropriate pull-up resistors. The switch supports I²C Fast Mode+ up to 1 MHz, offers hot-insertion capability, and integrates noise filters on SCL and SDA lines. It is ideally suited for servers, notebook PCs, and telecom equipment.