I2C Buffering - How to use TCA9517A

I2C
Written By Tyler Townsend

TCA9517A - Level Shifting I2C Bus Repeater

TCA9517A is an 8-pin I2C buffer/repeater from Texas Instruments. This device can buffer I2C signals and level shift / voltage translate from two different voltage logic levels (i.e. 1.8-V to 3.3-V).

The device can separate two I2C bus segments separating current and therefore separating capacitance - hence buffering. The I2C standard (owned by NXP) limits I2C bus segments to 400pF for standard mode (100kHz) and fast mode (400kHz) I2C. TCA9517A allows for two I2C bus segments of 400 pF each totaling for 800 pF of bus capacitance (see figure 1).

Tyler Townsend