Dual Bi-Directional I^{2C-Bus® and SMBus Voltage-Level Translator}

The FXWA9306 is a dual, bi-directional, I2C-bus and SMBus, voltage-level translator with an enable (OE) input that is operational from 1.0V to 3.6V (VCCA) and 1.8V to 5.5V (VCCB) without requiring a direction pin. As with standard I2C-bus systems, the pull-up resistors are required to provide the logic HIGH levels on the translator's bus. The FXWA9306 has a standard open-drain configuration of the I2C bus. The size of these pull-up resistors depends on the system, but each side of the translator must have a pull-up resistor. The device is designed to work with Standard-Mode, Fast-Mode, and Fast Mode Plus I2C-bus devices in addition to SMBus devices. The maximum frequency is dependent on the RC time constant, but generally supports up to 2MHz. All channels have the same electrical characteristics and there is a minimum deviation from one output to another in voltage or propagation delay. This is a benefit over discrete transistor voltage translation solutions, since the fabrication of the switch is symmetrical. The translator provides excellent ESD protection to lower voltage devices and at the same time protects less-ESD resistant devices.