Using The TPA301 EVM With the Plug-N-Play Evaluation Platform

3.3.3Muting

The TPA301 EVM is equipped with a mute (shutdown) control input pin. When this input is tied to VDD, the TPA301 amplifier IC on the module shuts down and assumes an ultra-low power mode. When the control input is tied to GND or allowed to float, amplifier operation resumes.

The typical application, as often found in notebook computers, portable audio products, and such, would have the internal speakers mute when headphones are plugged into the headphone jack, or have internal speakers mute when external speakers are connected. In applications using separate speaker and headphone amplifiers, the one not being used can be shut down (muted) to conserve power.

3.3.3.1Headphone Jack Control Signals

The platform headphone output jack (J10) contains an internal switch that changes the state of a pair of control lines when a plug is inserted. Each control line is pulled down by a 1-kΩresistor to ground (R4 and R5). The switch in the headphone jack pulls one line or the other up to VDD through a 240 Ω resistor (R3) depending on whether a plug is inserted in J10 or not (Figure 3 –6).

Figure 3–6. Mute/Mode and Polarity Control

 

VDD

 

 

R3

Polarity

 

240 Ω

 

JP8

 

 

J10

 

Lo

 

 

Headphone

Jack

 

Hi

R4

R5

SPK

1 kΩ

1 kΩ

(U2–U4)

JP6

 

 

 

 

Mode

U3, U4

 

 

 

 

 

 

 

 

 

 

 

 

 

Power

 

 

 

 

 

 

 

 

 

 

Amplifiers

 

 

 

 

Mute

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3.3.3.2Mute Polarity Select (JP8)

A three-pin jumper header (JP8), functioning as a SPDT switch, selects the control signal polarity by connecting either the active-low or the active-high line fromJthe headphone jack to jumper JP6.

To mute the TPA301 amplifier module when a plug is inserted into the

Jheadphone jack, jumper JP8 to Hi.

To mute the TPA301 amplifier module until a plug is inserted into the headphone jack, jumper JP8 to Lo.

3.3.3.3Mute Select (JP6)

A second three-pin jumper header (JP6) routes the control signal from the headphoneJ jack to either the mute or the mode pin of the evaluation module.

To mute the TPA301 amplifier module when a plug is inserted into the

Jheadphone jack, jumper JP6 to MUTE.

To not affect the TPA301 amplifier when a plug is inserted into the headphone jack, jumper JP6 to MODE or leave JP6 unjumpered.

3-8

Details

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Texas Instruments TPA301 manual Muting, Headphone Jack Control Signals
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TPA301 specifications

Texas Instruments TPA301 is a highly efficient, low-power audio amplifier designed for portable audio applications. This device is particularly well-suited for mobile phones, tablets, and other compact audio systems where space is limited but sound quality remains a priority. The TPA301 sits at the intersection of advanced audio technology and user-friendliness, making it a go-to choice for designers seeking a high-performance solution.

One of the main features of the TPA301 is its Class D architecture, which offers superior energy efficiency compared to traditional Class AB amplifiers. This means that less power is wasted as heat, allowing for longer battery life in portable devices. The TPA301 delivers up to 1.5W per channel into an 8-ohm load at low-distortion levels, ensuring that consumers experience clear audio reproduction, even at high volumes.

Furthermore, the TPA301 integrates several advanced technologies, including a built-in digital signal processor (DSP) that enables sophisticated audio processing capabilities. This DSP allows for features like active noise cancellation and equalization, enhancing the listening experience by tailoring the audio output according to the environment. The device also supports various audio inputs, including I2S, PCM, and TDM formats, providing design flexibility for developers.

The TPA301 is designed with a focus on compactness and thermal management, featuring a small package size that makes it ideal for space-constrained applications. Additionally, its low quiescent current contributes to minimal power consumption when the amplifier is in standby mode, making it a perfect fit for portable gadgets where battery longevity is critical.

Another notable characteristic of the TPA301 is its robust protection features, including over-temperature protection, short-circuit protection, and under-voltage lockout. These safety mechanisms ensure reliable operation under various conditions, protecting both the amplifier and connected speakers from damage.

In summary, Texas Instruments TPA301 stands out as an efficient, compact audio amplifier designed specifically for portable applications. Its combination of Class D efficiency, built-in DSP capabilities, wide audio format support, and comprehensive protection features make it an excellent choice for designers aiming for high-quality audio in a small footprint. Whether in smartphones or tablets, the TPA301 ensures consumers enjoy an unparalleled audio experience.
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