PCA9509 - Level translating I2C-bus/SMBus repeater
PCA9509 Features
* Bidirectional buffer isolates capacitance and allows 400 pF on port B of the device
* Voltage level translation from port A (1.35 V to VCC(B) 1.0 V) to port B (3.0 V to 5.5 V)
* Requires no external pull-up resistors on lower voltage port A
* Active HIGH repeater enable input