PCA9544

INTEGRATED CIRCUITS PCA9544 4-channel I2C multiplexer and interrupt controller Product specification Supersedes data of 1999 Apr 01 1999 Oct 07 Philips Semiconductors Philips Semiconductors Product specification 4-channel I2C multiplexer and interrupt controller PCA9544 FEATURES 1-of-4 bi-directional translating multiplexer Channel selection via I2C bus Operating supply voltage 2.5 to 3.6 V Operating temperature range 0°C to 70°C Power-up with all multiplexer channels deselected 3 address pins, allowing up to 8 devices on the I2C bus Low on resistance DESCRIPTION The PCA9544 is a 1-of-4 bi-directional translating multiplexer, controlled via the I2C bus. The SCL/SDA upstream pair fans out to four SCx/SDx downstream pairs, or channels. Only one SCx/SDx channel is selected at a time, determined by the contents of the programmable control register. Four interrupt inputs, one for each of the SCx/SDx downstream pair, are provided. One interrupt output, which acts as an AND of the four interrupt inputs, is provided. All I/O pins are 5 V tolerant. The pass gates of the multiplexer are constructed such that the VDD pin can be used to limit the maximum high voltage which will be passed by the PCA9544. This allows the use of different bus voltages on each SCx/SDx pair, so that 3.3 V parts can communicate with 5 V parts without any additional protection. External pull-up resistors can pull the bus up to the desired voltage level for this channel. PIN CONFIGURATION ...