The TCA9517 TCA9517A is a bidirectional buffer with level shifting capabilities for I²C and SMBus systems. It provides 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 SMBus systems to be extended without degradation of performance, even during level shifting.

The TCA9517 TCA9517A buffers both the serial data (SDA) and the serial clock (SCL) signals on the I²C bus, thus allowing two buses of up to 400-pF bus capacitance to be connected in an I²C application.

The TCA9517 TCA9517A has two types of drivers: A-side drivers and B-side drivers. All inputs and I/Os are over-voltage tolerant to 5.5 V, even when the device is unpowered (V_CCB and/or V_CCA = 0 V).

The TCA9517A offers a higher contention level threshold, V_ILC, than the TCA9517, which allows connections to slaves which have weaker pull-down ability.