Multiplexer Logic
Octal bidirectional translating switches controlled via an I2C bus enable selection of eight downstream bus channels. Hardware architectures implement PCA9548A devices to resolve slave address conflicts by isolating identical target devices onto separate sub-busses. Control registers accept write commands to enable or disable individual channel switches.
Channel Selection
Upstream master controllers write command bytes to internal control registers to activate downstream channels. Operating the PCA9548A allows simultaneous connection of multiple downstream sub-busses when bus capacitance remains within limits. Active high reset pins clear register contents, deselecting all channels during fault recovery.
Bus Expansion
Channel pass switches introduce series resistance into active bus paths, affecting signal transition times. Using a PCA9548A multiplexer allows level translation between different supply voltages across upstream master and downstream slave domains. System power consumption increases when multiple channels are active concurrently due to combined pull-up current paths.
High capacitive loading on individual downstream channels degrades rise times, requiring optimized pull-up resistor selection for each sub-bus segment.
Qualification Standard
Integrated circuit qualification verifies switch resistance, pin capacitance, and standby current across operating supply voltages. Automated test procedures confirm proper channel isolation and address decoding accuracy under maximum bus loading. Component specifications define thermal operating limits in surface mount packages.