This TCA9509 integrated circuit is an I²C bus/SMBus Repeater for use in I²C/SMBus systems. It can also provide bidirectional voltage-level translation (up-translation/down-translation) between low voltages (down to 0.9 V) and higher voltages (2.7 V to 5.5 V) in mixed-mode applications. This device enables I²C and similar bus systems to be extended, without degradation of performance even during level shifting.

The TCA9509 buffers both the serial data (SDA) and the serial clock (SCL) signals on the I²C bus, thus allowing 400-pF bus capacitance on the B-side. This device can also be used to isolate two halves of a bus for voltage and capacitance.

The TCA9509 has two types of drivers – A-side drivers and B-side drivers. All inputs and B-side I/O’s are overvoltage tolerant to 5.5V. The A-side I/O’s are overvoltage tolerant to 5.5 V when the device is unpowered (V_CCB and/or V_CCA = 0V).