9 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. Customers should validate and test their design

implementation to confirm system functionality.

9.1 Application Information

The TMUX13xx family offers protection against injection current invents across a wide operating supply range

(1.62 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 pins support Fail-Safe Logic which allows for operation

up to 5.5 V, regardless of the state of the supply pin. This feature stops the logic pins from back-powering the

supply rail while the injection current circuitry prevents the signal path from back-powering the supply. These

features make the TMUX13xx a family of general purpose multiplexers and switches that can reduce system

complexity, board size, and overall system cost.

9.2 Typical Application

One useful application to take advantage of the TMUX13xx features is multiplexing various signals into an ADC

that is integrated into a MCU. Utilizing an integrated ADC in a MCU allows a system to minimize cost with a

potential tradeoff of system performance when compared to an external ADC. The multiplexer allows for multiple

inputs/sensors to be monitored with a single ADC pin of the device, which is critical in systems with limited I/O.

The TMUX1309 is suitable for similar design example using differential signals, or as two 4:1 multiplexers.

System Inputs &

Sensors

LDO #1

D

S1

S2

S3

S4

S5

S6

S7

S8

Integrated

12-bit ADC

A0

A1

A2

EN

MCU

LDO #2

LM20

Analog Temp.

Sensor

LM20

Analog Temp.

Sensor

GND

1.8V Logic

I/O

LM20

Analog Temp.

Sensor

LDO #3

RAM

FLASH

Port I/O

TIMERS

Figure 9-1. Multiplexing Signals to Integrated ADC

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TMUX1308, TMUX1309

SCDS426C – MARCH 2020 – REVISED AUGUST 2020

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