PCA9509 Level Translating I2C-Bus/SMBus Repeater

NXP Semiconductors PCA9509 Level Translating I²C-Bus/SMBus Repeater provides two voltage supplies that enable the processor low voltage 2-wire serial bus to interface with the standard I²C-bus or SMBus I/O. While retaining all the operating modes and features of the I²C-bus system during the level shifts, The PCA9509 also permits extension of the I²C-bus by providing bidirectional buffering for both the data (SDA) and the clock (SCL) lines, thus enabling the I²C-bus or SMBus maximum capacitance of 400pF on the higher voltage side. Port A allows a voltage range from 0.8V to 1.5V and requires no external pull-up resistors due to the internal current source. Port B allows a voltage range from 2.3V to 5.5V and is overvoltage tolerant. Both port A and port B SDA and SCL pins are high-impedance when the PCA9509A is unpowered.