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, as well as validating and testing their design

implementation to confirm system functionality.

9.1 Application Information

TMUX4827 is part of the beyond the supply switches and multiplexers family of devices. This means that this

device can switch signals from -12 V to 12 V with a low voltage supply from 1.8 to 5.5 V. Additionally, the

TMUX4827 features powered-off protection, which by design keeps the switches open even when there is no

supply. This unique feature combination enables the TMUX4827 to be extremely versatile for a wide variety of

applications such as boosted outputs and high common mode offsets.

9.2 Typical Applications

9.2.1 Audio Amplifier Switching

Often, there are multiple audio sources in a system giving the user options on which source will connect to the

speaker. To enable switching between these sources, a TMUX4827 can be used. The line-in can be biased to

a negative voltage, and class-D amplifier output can be higher than the typically used 3 V and 5 V supplies. So

any circuitry connected needs to handle this bipolar voltage. This same scheme can be used in systems where

there are multiple speaker outputs and one source as well. Here the switch is used to switch from an internal

speaker to an external one. Figure 9-1 shows the block diagram for these applications. Here a TLV320AIC3x is

used as an audio codec driving a TPA313x class D audio amplifier. Additionally, if IEC protection is needed on

the external connectors (audio jack input or external speaker), then a 2 channel TPD2E007 can be used.

The TMUX4827 can be used to switch up to ±12 V with a supply voltage from 1.8 V to 5.5 V. The supply

can also be driven directly with a GPIO, allowing the user to put the device into ultra-low power mode. In this

mode, the TMUX4827 operates with powered-off protection, so any high voltage present on the inputs will not

propagate to the outputs. This feature allows for the correct power up cycling and increases system robustness.

Additionally, the TMUX4827 features excellent THD+N performance, so there is minimal impact to the audio

signal quality through the switch. This allows the system designer to save a significant portion of board area

without impacting signal integrity.

Class D Audio

Amplifier

TPA313x

SEL

VDD

Decoder

Audio Codec

TLV320AIC3253

L

R

GPIO

Class D Audio

Amplifier

TPA313x

Audio Codec

TLV320AIC3253

L

R

GPIO

SEL

VDD

Decoder

Internal

External

TPD2E007

TPD2E007

Figure 9-1. Audio Amplifier Switching

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TMUX4827

SCDS457A – MAY 2023 – REVISED JUNE 2023

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