PCA9545APW,112

The PCA9545APW is a 4-channel quad bidirectional I²C-bus Switch with an interrupt logic and reset. 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. Four interrupt inputs, INT0\ to INT3\, one for each of the downstream pairs, are provided. one interrupt output, INT, acts as an AND of the four interrupt inputs. An active low reset input allows the switch 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-bus 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 is passed by the switch. External pull-up resistors pull the bus up to the desired voltage level for each channel.

• 4 Active low interrupt inputs
• Active low interrupt output
• Active low reset input
• 2 Address pins allowing up to 4 devices on the I²C-bus
• Channel selection via I²C-bus, in any combination
• Power-up with all switch channels deselected
• Low Ron switches
• No glitch on power-up
• Supports hot insertion
• Low standby current
• Latch-up protection exceeds 100mA per JESD78

Applications

Communications & Networking