PCA9546

INTEGRATED CIRCUITS PCA9546 4-channel I2C switch with reset Product data sheet Supersedes data of 2002 Feb 19 2004 Sep 30 Philips Semiconductors Philips Semiconductors Product data sheet 4-channel I2C switch with reset PCA9546 DESCRIPTION The PCA9546 is a quad bi-directional translating switch controlled by the I2C-bus. The SCL/SDA upstream pair fans out to four downstream pairs, or channels. Any individual SCx/SDx channel or combination of channels can be selected, determined by the contents of the programmable Control Register. An active-LOW reset input allows the PCA9546 to recover from a situation where one of the downstream I2C-buses is stuck in a LOW state. Pulling the RESET pin LOW resets the I2C state machine and causes all the channels to be deselected as does the internal power on reset function. The pass gates of the switches are constructed such that the VDD pin can be used to limit the maximum high voltage which will be passed by the PCA9546. This allows the use of different bus voltages on each pair, so that 1.8 V, 2.5 V, or 3.3 V parts can communicate with 5 V parts without any additional protection. External pull-up resistors pull the bus up to the desired voltage level for each channel. All I/O pins are 5 V tolerant. FEATURES 1-of-4 bi-directional translating switches I2C interface logic; compatible with SMBus standards Active LOW Reset Input 3 address pins allowing up to 8 devices on the I2C-bus Channel selection via I2C-bus, in any combin...