Data Sheet

11
TCA9548A
www.ti.com SCPS207F –MAY 2012–REVISED NOVEMBER 2016
Product Folder Links: TCA9548A
Submit Documentation FeedbackCopyright © 2012–2016, Texas Instruments Incorporated
8 Detailed Description
8.1 Overview
The TCA9548A is an 8-channel, bidirectional translating I
2
C 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 must one of the downstream I
2
C 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 cause all channels to be deselected.
The connections of the I
2
C data path are controlled by the same I
2
C master device that is switched to
communicate with multiple I
2
C 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.