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.

9.1 Application Information

The TMUX12xx family offers good system performance across a wide operating supply (1.08 V to 5.5 V). These

devices include 1.8 V logic compatible control input pins that enable operation in systems with 1.8 V I/O rails.

Additionally, the control input pin supports Fail-Safe Logic which allows for operation up to 5.5 V, regardless

of the state of the supply pin. This protection stops the logic pins from back-powering the supply rail. These

features of the TMUX12xx, a family of general purpose multiplexers and switches, reduce system complexity,

board size, and overall system cost.

9.2 Typical Application

9.2.1 Switchable Operational Amplifier Gain Setting

Another example application of the TMUX1248 is to change an Op Amp from unity gain setting to an inverting

amplifier configuration. Utilizing a switch allows a system to have a configurable gain and allows the same

architecture to be utilized across the board for various inputs to the system. Figure 9-1 shows the TMUX1248

configured for gain setting application.

TLV9001

Inverting

Input

Output

Unity Gain

R

R

TMUX1248

1.8 V

S1

D

S2

SEL

Figure 9-1. Switchable Op Amp Gain Setting

9.2.1.1 Design Requirements

This design example uses the parameters listed in Table 9-1.

Table 9-1. Design Parameters

PARAMETERS

VALUES

Input Signal

0 V to 2.75 V

2.75 V

±2.75 V

Mux I/O signal range

Control logic thresholds

1.8 V compatible (up to 5.5 V)

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TMUX1248

SCDS447 – JULY 2021

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