8 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification,

and TI does not warrant its accuracy or completeness. TI’s customers are responsible for

determining suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

8.1 Application Information

The TMUX121 is an analog high-speed mux or demux that can be used for routing differential as well as single

ended signals through it. The device can be used for many interfaces including I2C and I3C.

An available GPIO pin of a controller or hard tie to voltage level H or L can easily control the mux or

demux selection pin (SEL) of the device as an application requires. The switch path is passive and therefore

bidirectional.

8.2 Typical Applications

8.2.1 Signal Expansion (I3C and I2C)

There are many applications in which microprocessors or controllers have a limited number of I/Os. The

TMUX121 solution can effectively expand the limited I/Os by switching between multiple buses to interface them

to a single microprocessor or controller. A common application where the TMUX121 is as a I3C 1:2 multiplexer.

In this application, the TMUX121 is used to route communicating between different peripherals from a single

controller or driver within a server, as shown in Figure 8-1. The high bandwidth of the TMUX121 will preserve

signal integrity at even the fastest communication protocols that may be used in server applications, such as I3C.

Also, because I3C is backwards compatible, any of the peripherals can also be I2C, and the TMUX121 will still

support it.

3.3 V

I3C/I2C Driver

I3C/I2C Peripheral

Port B

EN SEL

GND

D1

D2

VDD

Switch

Control Logic

0.1 µF

I3C/I2C Peripheral

Port A

S1A

S2A

S1B

S2B

SCL

SDA

SCL

SDA

SCL

SDA

Figure 8-1. Typical Application

TMUX121

SCDS381 – AUGUST 2023

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