I2C Switches Multiplex On A Single Bus

Debuting as the industry’s first family of I2C-controlled switches that can connect multiple devices with the same address on a single bus, the PCA954x switches allow voltage level shifting between devices operating at 5, 3.3, 2.5, or 1.8V at serial clock frequencies up to 400 kHz. They provide multiplexing and interrupt control and are said to eliminate the need for glue logic and general purpose I/Os. The switches include a hardware-reset pin that returns the device to the default state of no-channels-selected, which bypasses the step of cycling power to restore the bus from a lock-up situation. Four devices with two-, four-, or eight-channel configurations are currently in production and will be available in both TSSOP and SO packages. The PCA9543, PCA9545, PCA9546, and PCA9548 are priced at $0.77, $0.92, $0.75 and $1.19, respectively, in either package type, each/10,000. PHILIPS SEMICONDUCTORS INC., Sunnyvale, CA. (800) 447-1500.