7 Detailed Description

7.1 Functional Block Diagram

The TMUX2821 is a 1:1, 2-channel and the TMUX2819 is a 2:1 1-channel multiplexer or demultiplexer. Each

input is turned on or turned off based on the state of the select lines and VDD pin.

SA

SB

D

SEL

V

DD

Decoder

S2

S1

D1

SEL1

V

DD

Decoder

D2

EN

SEL2

7.2 Device Functional Modes

Table 7-1 provides the truth table for the TMUX28xx.

Table 7-1. TMUX2821 Truth Table

VDD SELx

Channel x

0

X(1)

All channels are off (Hi-Z). Device is in power-off

protection.

1

0

Channel x OFF

1

1

Channel x ON

Table 7-2. TMUX2819 Truth Table

VDD SEL EN

Selected Input Connected To Drain (D) Pin

0

X(1)

X

All channels are off (Hi-Z). Device is in power-off

protection.

1

X

0

All channels are off (Hi-Z). Device is in power-off

protection.

1

0

1

SxA

1

1

1

SxB

(1)

X denotes do not care.

7.3 Feature Description

7.3.1 Beyond the Supply

The TMUX28xx supports signal voltages beyond the supply on the source (Sx) and drain (Dx) pins up to ±5.5V.

This feature allows both AC and DC bidirectional signals above VDD and below ground to pass through the

switch without distortion, using a unidirectional supply. The device remains within the performance mentioned in

the Electrical Characteristics.

www.ti.com

TMUX2821, TMUX2819

SCDS488 – DECEMBER 2025

Copyright © 2025 Texas Instruments Incorporated

Submit Document Feedback

19

Product Folder Links: TMUX2821 TMUX2819