9.1 Overview

The TCA9517 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 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 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).