PCA9545APW – Interface Specialized IC TSSOP-20

The PCA9545A/45B/45C is a quad bidirectional translating switch operated by the IC-bus. The SCL/SDA upstream pair spreads out to four downstream pairs, or channels. Individual SCx/SDx channels or combinations of channels can be selected based on the contents of the programmable control register. Four interrupt inputs, INT0 through INT3, one for each downstream pair, are supplied. One interrupt output, INT, works as an AND for the four interrupt inputs. The PCA9545A/45B/45C has an active LOW reset input to recover from a trapped LOW state on a downstream IC bus. Pulling the RESET pin LOW resets the IC-bus state machine and deselects all channels, including the internal power-on reset mechanism. The pass gates of the switches are designed so that the VDD pin can be utilized to limit the maximum high voltage passed by the PCA9545A/45B/45C. This enables the use of multiple bus voltages on each pair, allowing 1.8 V, 2.5 V, or 3.3 V parts to communicate with 5 V parts without requiring additional safety. External pull-up resistors bring the bus voltage up to the necessary level for each channel. All I/O pins are 5 V tolerant.
Datasheet