15 Detailed Description

15.1 Functional Block Diagram

The TMUX4821 is a 1:1, 2-channel and the TMUX4819 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

15.2 Device Functional Modes

Table 15-1 provides the truth table for the TMUX48xx.

Table 15-1. TMUX4821 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 15-2. TMUX4819 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.

15.3 Feature Description

15.3.1 Beyond the Supply

The TMUX48xx supports signal voltages beyond the supply on the source (Sx) and drain (Dx) pins up to ±15V.

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.

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TMUX4821, TMUX4819

SCDS487A – OCTOBER 2025 – REVISED DECEMBER 2025

Copyright © 2025 Texas Instruments Incorporated

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Product Folder Links: TMUX4821 TMUX4819