SIngle-Ended Operation, Inputs and Gain | Texas Instruments TPA0202

The TPA0202 Audio Power Amplifier Evaluation Module

3.2.4SIngle-Ended Operation

For single-ended operation, the module SE/BTL control input pin must be held high. The speaker (or headphone) load is connected to the module OUT+ output pin through a coupling capacitor, and to platform/system ground. A 470 -μF electrolytic coupling capacitor is provided on the platform in the signal path to the headphone output jack for this purpose, and a control signal from the platform headphone jack can be routed to the module control input pin to switch the TPA0202 IC to the single-ended mode.

In the single-ended mode, the amplifiers inside the TPA0202 IC that drive the OUT± lines do not operate and do not dissipate any power. The OUT± pins go into a high-impedance state and can be left connected or allowed to float.

3.2.5Inputs and Gain

Each channel has two separate signal inputs that are pin-selectable. They are called line (L) and headphone (HP). The line inputs are fixed at a gain of 10 and the headphone inputs are fixed at a gain of ±1. In the typical application in which the TPA0202 powers small speakers until headphones are plugged in, the difference in the gain selected for the two inputs provides approximately the same perceived listening level in the headphones as from the speakers. An input multiplexor in the amplifier IC selects between the two inputs according to the state of the HP/LINE IC pin.

Gain for each input is determined by the ratio of the input resistor to the feedback resistor on the module PCB. And, although the input gains are fixed at the factory, they can be adjusted by changing the resistor values on the module PCB. However, care must be taken because the surface-mount solder pads on the PCB are somewhat fragile and will not survive many soldering/desoldering operations. In addition, the values selected for the gain-setting resistors affect the performance of the internal depop circuitry (see the TPA0202 data sheet).

The TPA0202 amplifier IC, as most other amplifiers, exhibits its best distortion and noise performance at lower gain levels (see the TPA0202 data sheet). Even so, the TPA0202 at its highest gain setting has significantly less distortion than most low-cost speakers.

Gain versus total harmonic distortion (THD) should be considered in each application. Both the module input signal level and the TPA0202 module gain should be adjusted to obtain the lowest overall distortion level for a particular overall gain. A quick rule of thumb (everything else being equal): the module input signal level should be as high as possible without clipping or overloading the TPA0202 input, and the TPA0202 gain should be kept as low as possible.

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Details

TPA0202 specifications

The Texas Instruments TPA0202 is a high-performance Class-D audio amplifier designed for a variety of portable audio applications. Renowned for its efficiency and sound quality, the TPA0202 is an ideal choice for battery-operated devices such as mobile phones, tablet computers, and other handheld devices. With the continuous push for better audio experiences in compact formats, the TPA0202 stands out with its impressive specifications and features.

One of the key characteristics of the TPA0202 is its power efficiency. Operating at a high efficiency rate of up to 90%, this Class-D amplifier minimizes heat generation, allowing it to deliver more power to the audio output while extending battery life. This efficiency is especially crucial for portable devices, where battery performance is a key consideration.

The TPA0202 supports an output power of 2 watts per channel into 4 ohms, making it capable of driving small speakers or headphones with excellent sound quality. The device features a built-in differential input stage that enhances noise immunity, thereby ensuring cleaner audio reproduction. It also supports a wide supply voltage range from 3V to 5.5V, contributing to its versatility in different applications.

In terms of audio quality, the TPA0202 boasts low total harmonic distortion (THD) and exceptional linearity, resulting in rich, clear audio output. Additionally, it comes equipped with selectable gain settings, allowing designers to tailor the amplifier to various output requirements and system designs.

The amplifier also integrates various protection features, including thermal shutdown, short-circuit protection, and undervoltage detection, ensuring robust operation under different conditions. The TPA0202 is also simple to implement in designs, with a minimal external component requirement, further enhancing its appeal to engineers seeking quick and efficient solutions for audio amplification needs.

Moreover, the compact package size of the TPA0202 allows for easy integration into space-constrained designs. With its combination of high efficiency, excellent audio quality, and protective features, the Texas Instruments TPA0202 continues to be a compelling choice for developers looking to enhance audio performance in portable and battery-operated devices. Whether for consumer electronics or in more specialized applications, the TPA0202 delivers reliable and impressive sound amplification, making it a go-to component for modern audio solutions.