I2C bus buffer/repeater provides bidirectional level shifting between low and higher voltages

Texas Instruments’ TCA9803 is a dual-channel bidirectional buffer intended for I2C bus and SMBus/PMBus systems. It provides bidirectional level shifting (up-translation and down-translation) between low voltages (down to 0.8V) and higher voltages (1.65V to 3.6V). The device features an internal current source on the B-side of the device, allowing the removal of external pull-up resistors on the B-side. The current source also provides an improved rise time and ultra-low power consumption.   The device is able to provide true buffering (rather than a pass-FET solution) without using a static voltage offset or incremental offset. This means that the VOL on both the A and B sides of the device are very low (approximately 0.2V), helping to eliminate communication issues as a result of fixed VIL      thresholds. Another key feature of the device is that there are no power sequencing requirements, or power supply dependencies. VCCA can be greater than, less than, or equal to VCCB. This gives the system designer flexibility with how the device is used.