TCA9548A_15 Datasheet, PDF (10/35 Pages) Texas Instruments – Low-Voltage 8-Channel I2C Switch With Reset

TCA9548A
SCPS207E – MAY 2012 – REVISED OCTOBER 2015
8 Detailed Description
www.ti.com
8.1 Overview
The TCA9548A is an 8-channel, bidirectional translating I²C switch. The master SCL/SDA signal pair is directed
to eight channels of slave devices, SC0/SD0-SC7/SD7. Any individual downstream channel can be selected as
well as any combination of the eight channels.
The device offers an active-low RESET input which resets the state machine and allows the TCA9548A to
recover should one of the downstream I²C buses get stuck in a low state. The state machine of the device can
also be reset by cycling the power supply, V_CC, also known as a power-on reset (POR). Both the RESET function
and a POR will cause all channels to be deselected.
The connections of the I²C data path are controlled by the same I²C master device that is switched to
communicate with multiple I²C slaves. After the successful acknowledgment of the slave address (hardware
selectable by A0, A1, and A2 pins), a single 8-bit control register is written to or read from to determine the
selected channels.
The TCA9548A may also be used for voltage translation, allowing the use of different bus voltages on each
SCn/SDn pair such that 1.8-V, 2.5-V, or 3.3-V parts can communicate with 5-V parts. This is achieved by using
external pull-up resistors to pull the bus up to the desired voltage for the master and each slave channel.
10
Submit Documentation Feedback
Product Folder Links: TCA9548A
Copyright © 2012–2015, Texas Instruments Incorporated