Hot-selling and scarce PCA9543APW 2-channel I2C-bus switch with interrupt logic and reset TSSOP14 spot stock

Product Descriptions

The PCA9543A/43B/43C is a bidirectional translating switch, controlled by the I2C-bus. The SCL/SDA upstream pair fans out to two downstream pairs, or channels. Any individual SCx/SDx channels or combination of channels can be selected, determined by the contents of the programmable control register. Two interrupt inputs, INT0 and INT1, one for each of the downstream pairs, are provided. One interrupt output, INT, which acts as an AND of the two interrupt inputs, is provided.

An active LOW reset input allows the PCA9543X 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 I 2C-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 will be passed by the PCA9543X. This allows the use of different bus voltages on each SCx/SDx 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.

The PCA9543A, PCA9543B and PCA9543C are identical except for the fixed portion of the slave address

Product Features

■ 1-of-2 bidirectional translating switches

■ I2C-bus interface logic; compatible with SMBus standards

■ 2 active LOW interrupt inputs

■ Active LOW interrupt output

■ Active LOW reset input

■ 2 address pins allowing up to 4 devices on the I2C-bus

■ Alternate address versions A, B and C allow up to a total of 12 devices on the bus for larger systems or to resolve address conflicts

■ Channel selection via I2C-bus, in any combination

■ Power-up with all switch channels deselected

■ Low Ron switches

■ Allows voltage level translation between 1.8 V, 2.5 V, 3.3 V and 5 V buses

■ No glitch on power-up

■ Supports hot insertion

■ Low standby current

■ Operating power supply voltage range of 2.3 V to 5.5 V

Product Specification

Product Photos

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