The TPA005D12 Class-D Audio Power Amplifier Evaluation Module

3.2.4Class-D Differential Inputs

The TPA005D12 EVM line inputs allow the use of a single-ended or differential audio source. The differential input stage of the amplifier cancels any noise that appears on both input lines of a channel. To use the EVM with a differential source, connect the positive lead of the audio source to the RIN+/LIN+ inputs and the negative lead to the RIN±/LIN± inputs. To use the EVM with a single-ended source, connect the positive lead of the audio source to the RIN+/LIN+ inputs and the ground lead to the RIN±/LIN± inputs. This ac grounds the input capacitors on the negative terminals and balances the input impedance of the class-D amplifier's positive and negative input terminals, preventing voltage differences that result in popping in the speakers.

3.2.5Control and Indicator Circuits

Three main control circuits are provided with the TPA005D12. The mute circuit grounds the output of the active amplifier, and the shutdown circuit places the entire device into a power-saving sleep mode to minimize current consumption. Each of these inputs is TTL compatible: less than 0.8 V applied to these pins is considered a logic low, and any voltage greater than 2 V is considered a logic high.

Two indicator pins are also provided for feedback when an under-voltage, over-current, or thermal fault exists. Module pins are provided for easy connection of off-board control and monitoring. There are two active low fault indicator pins on the TPA005D12 amplifier IC (IC pins 40 and 41) that provide feedback when a fault condition exists. Signals on these pins provide the status of the class-D amplifier: operational, over-current, thermal fault, and under-voltage lockout. Table 3±1 lists the possible output conditions of these pins and a description of the fault indicated.

Table 3±1. TPA005D12 Class-D EVM Fault Indicator Table

FAULT 0

FAULT 1

DESCRIPTION

(TP 2)

(TP 3)

 

 

 

 

1

1

No fault. Ð The device is operating normally.

 

 

 

1

0

Charge pump under-voltage lockout (VCP-UV) fault Ð the charge pump voltage is < (PVDD + 6V).

 

 

All low-side transistors are turned on, shorting the load to ground. Normal operation resumes when

 

 

the charge pump voltage is restored (not a latched fault), however the Fault indication remains

 

 

active until cleared by cycling MUTE, SHUTDOWN, or the power supply.

 

 

 

0

1

Over-current fault Ð the output current limit has been exceeded. All output transistors are switched

 

 

off, causing the load to see a high impedance state. This is a latched fault and is cleared by cycling

 

 

MUTE, SHUTDOWN, or the power supply.

 

 

 

0

0

Thermal fault Ð the internal junction temperature has exceeded 125 °C. All of the low-side

 

 

transistors are turned on, shorting the load to ground. Once the junction temperature drops by 20°C

 

 

and is below 125°C, normal operation resumes (not a latched fault). The Fault indication remains

 

 

active until cleared by cycling MUTE, SHUTDOWN, or the power supply.

3-8

Details

Page 21 Page 23
Page 22
Image 22
Texas Instruments TPA005D12 manual Class-D Differential Inputs, Control and Indicator Circuits
Page 21 Page 23

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.
Top Page Image Contents