Using The TPA005D12 Class-D EVM With the Plug-N-Play Platform

3.4.4Shutdown

The TPA005D12 class-D EVM is equipped with a shutdown control input pin. When this input is tied to GND, the TPA005D12 amplifier IC on the module enters the shutdown mode and dissipates very little power. When the EVM control input is tied to VDD or allowed to float, amplifier operation resumes.

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

The TPA005D12 EVM shutdown control pin connects to the platform Mute line of JP6 when the EVM is inserted in the plug-n-play platform. When JP6 is set to Mute and JP8 is set to Lo, the class-D EVM will operate normally until a headphone plug is inserted into platform jack J10 and the class-D amplifier is placed into shutdown. Once the jack is removed from J10, the class-D EVM again becomes active. Note that when JP6 is set to mute and the class-D EVM shutdown pin is activated, the platform current increases by approximately 20 mA. This current is set by the connection of the 240-Ωplatform resistor (R3) to ground through the EVM shutdown switch.

3.4.4.1Headphone 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 (Figure 3±8). 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-Ωresistor (R3) depending on whether a plug is inserted in J10 or not.

Figure 3±8. 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

U2

 

 

Power

Mute

Amplifier

 

3-14

Details

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Texas Instruments TPA005D12 manual Shutdown, Headphone Jack Control Signals
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TPA005D12 specifications

The Texas Instruments TPA005D12 is a highly regarded digital audio power amplifier that is engineered for high-performance applications. It is part of TI's TPA series, which is known for its efficient power delivery and superior sound quality. The TPA005D12 is designed to drive passive speakers while ensuring minimal power loss and efficient heat management.

One of the standout features of the TPA005D12 is its ability to provide 5 watts of continuous output power per channel into an 8-ohm load with a low total harmonic distortion (THD) rating. This makes it suitable for use in a variety of audio applications, including computer speakers, soundbars, and portable audio systems. The amplifier operates from a single supply voltage, ranging typically from 4.5V to 14V, allowing for flexible integration into different power supply environments.

The TPA005D12 adopts Class-D amplification technology, which significantly enhances power efficiency compared to traditional linear amplifiers. Class-D amplifiers convert the input audio signal into a series of pulse-width modulated signals, resulting in increased power savings and reduced heat generation. This not only improves the overall energy efficiency but also contributes to a longer operational lifespan for devices utilizing this technology.

Additionally, the TPA005D12 features an integrated thermal and short-circuit protection mechanism, which helps safeguard the amplifier from potential damage due to excessive temperatures or electrical faults. This reliability factor is crucial for manufacturers looking to create robust consumer electronics.

Another important characteristic is its integrated low-noise power supply rejection ratio (PSRR), which helps maintain sound clarity and reduces the impact of power supply noise on audio quality. The TPA005D12 also supports differential input signals, which can improve common-mode noise rejection and further enhance audio performance.

The device is offered in a compact package suitable for space-constrained applications, enabling easy integration into various designs. With a combination of low cost, high efficiency, and excellent audio performance, the Texas Instruments TPA005D12 stands out as a top choice for developers and engineers seeking reliable audio amplification solutions. Whether in home entertainment systems or personal audio devices, the TPA005D12 is designed to deliver exceptional sound quality with a minimal footprint.
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