PAM8403 Amplifier Board: Pinout, Features, and Datasheet

The PAM8403 is an amplifier board that readily accepts a 5V input and is capable of driving two 3W + 3W stereo speakers. It is the preferred choice for individuals in search of a Class-D stereo audio amplifier in a compact board layout. This amplifier enables users to achieve superb audio replication from a stereo input source. Its distinctive feature lies in its ability to directly drive speakers via its output.

Overview of PAM8403 Amplifier Board

The primary power amplifier IC featured in this module is the PAM8403, as depicted in the image below. In addition to the IC, the module includes various components like capacitors and resistors.

The PAM8403 amplifier board is a dual-channel (stereo) amplifier capable of delivering a combined 6W output (3W+3W). A critical aspect of any major amplifier system is short circuit protection, and the PAM8403 boasts built-in protection to ensure trouble-free operation. Notably, the PAM8403 Amplifier IC itself does not require the use of a heat sink, making it an excellent choice for custom speaker projects. It can directly drive 4Ω or 8Ω speakers, and it's imperative to match it with a speaker rated at no more than 3W output.

As a stereo amplifier board, the input section accommodates both left (L) and right (R) inputs with a common ground between them. It can amplify a variety of audio inputs, delivering a robust 3W + 3W audio output.

This amplifier module offers a maximum gain of 24 dB with 10% THD when provided with a 5V DC input and connected to a 4 Ohm load. The absence of a heat sink not only saves board space but also does not compromise thermal protection—a vital feature for such a low-wattage amplifier module.

Pin Description of PAM8403 Amplifier Board

Pin Name	Description
L	Audio Jack (TRS-Tip) Left Channel Input
Gnd	Audio Jack (TRS-Sleeve) Ground Channel Input
R	Audio Jack (TRS-Ring) Right Channel Input
5v(+)	5v DC Power VDD
5v(-)	5v DC Power GND
L(+)	Left Channel Positive Output
L(-)	Left Channel Negative Output
R(+)	Right Channel Positive Output
R(-)	Right Channel Negative Output

Features

• Wide Voltage Compatibility: Supports power supplies within the range of 2.5V to 5.5V DC.

• Stereo Powerhouse: Dual-channel configuration delivers a robust 3W+3W output with a 4Ω Load at 10% THD, all at just 5V DC.

• Maximum Gain of 24 dB: Amplifies signals effectively for enhanced audio performance.

• Filterless Design: Simplifies setup by eliminating the need for low-pass output filters.

• Low Quiescent Current and Minimal EMI: Ensures efficient and interference-free operation.

• Operating Temperature Range: Withstands extreme conditions, functioning reliably between -40°C to +85°C.

• Short Circuit Protection: Incorporates a built-in safeguard against potential damage from short circuits.

• Thermal Shutdown: Prevents overheating, ensuring prolonged operational life.

• Exceptional Noise Control: Produces clear, high-quality audio with minimal noise interference.

• Up to 90% Efficiency: Offers power-efficient operation.

• Compact Form Factor: Measures a mere 2.1 x 1.8 x 0.3 cm (LxWxH), facilitating versatile applications.

PAM8403 Amplifier Board Interfacing Diagram

Here is the circuit diagram for interfacing two 3W speakers with the PAM8403 Amplifier Board. The board can be powered using any voltage ranging from 2.5V to 5V DC, but it is recommended to use a 5V input for optimal output performance.

This diagram illustrates how to connect the PAM8403 Amplifier Board to two 3W speakers to achieve high-quality audio output. Ensure you use the recommended 5V input voltage for the best performance.

How to use PAM8403?

Step 1: Basic Information

It's important to note that the PAM8403 is a compact amplifier that operates on a 5V input and delivers a 6W output. This makes it an ideal choice for custom speaker projects, primarily because it doesn't require a heat sink. Furthermore, compared to other audio amplifiers, the PAM8403 offers a cost-effective solution while delivering robust stereo amplification. However, to harness its full potential, proper wiring and a reliable power supply are essential. Keep in mind that using a power supply exceeding 6V can damage the equipment.

Step 2: Cautionary Measures

Avoid attempting to run your project on a breadboard, as it can result in high distortion rates. When it comes to connections, steer clear of coaxial cables for both DC and audio input, as they can introduce unwanted RF interference and negatively impact audio quality. Additionally, be aware that the PAM8403 amplifier board is available in two variants: one with volume control and one without. Ensure you use shielded and unshielded cables for the respective outputs.

Step 3: Identifying TRS Pins with Three Leads

Typically, a basic aux or audio cable consists of three wires: two signal wires and one ground wire (often yellow or black). To identify which wire connects to the lead, follow these steps:

1. Use a multimeter in continuity mode.

2. Connect one multimeter cable to the bottom lead of the pin and the other to any of the available wires.

3. A successful connection will result in a beep.

4. Repeat the process for the signal wires, noting that they can be interchanged since they allow flexibility.

Step 4: Identifying TRS Pins with Four Leads

In the case of TRS pins with four leads, there are four wires: two signal wires, one ground wire, and one positive voltage wire. These are typically found inside headphone amplifiers.

Step 5: USB Cable

A standard USB cable comprises four colored wires: red, black, white, and green. For your PAM8403 amplifier project, you'll only need the +5V (red) and ground (black) wires. Solder these wires to their respective pads on the board after removing the aluminum shielding under the first plastic layer and the aluminum wires surrounding the colored wires.

Step 6: Speaker Connection

The PAM8403 amplifier can drive various types of speakers, but for optimal results, consider using an FRS-rated 4-ohm, 3-watt speaker.

Step 7: Volume Control

For volume control, you'll need a 10K ohm stereo potentiometer. Follow these steps:

1. Connect the left output to the top-left corner pin of the potentiometer.

2. Use a 10uF capacitor to link the opposite end of the capacitor to the top-middle pin of the potentiometer. Connect the positive end of the

   electrolytic capacitor to the left input of the amplifier.

3. Connect the top-right corner pin of the potentiometer to the ground pin of the amplifier.

4. Link the right output to the bottom-left corner pin of the potentiometer.

5. Use another 10uF capacitor to connect the negative terminal of the capacitor to the bottom-middle pin of the potentiometer. Connect the

   positive terminal to the right input of the amplifier.

6. Join the amplifier's ground to the bottom-right pin of the potentiometer.

Step 8: Testing

In the final step, connect the power supply to confirm whether the amplifier is functioning correctly. You may hear a slight humming sound initially, but it should disappear once you connect the audio cables.

Applications

• Speaker Output in LCD Monitors / TV Projectors: Enhance the audio experience of your LCD monitors or TV projectors by using the

  PAM8403 Amplifier Board to drive speakers for improved sound quality.

• Speaker Output Amplifier in Notebook Computers: Upgrade the audio output of notebook computers by integrating the PAM8403

  Amplifier Board, providing clearer and more powerful sound.

• Portable Speakers: Build portable speaker systems with the PAM8403 Amplifier Board for on-the-go audio solutions, perfect for outdoor

  activities or gatherings.

• Portable DVD Players: Improve the audio performance of portable DVD players, ensuring a better entertainment experience while on

  the move.

• Game Machines: Enhance the sound effects and audio output of game machines, creating a more immersive gaming experience.

• Custom Amplifier-Based Projects: Utilize the PAM8403 Amplifier Board in various amplifier-based projects where space constraints and a

  5V power supply are essential requirements.

PAM8403 Alternatives

Consider exploring alternatives like PAM8406 or TDA7265.

PAM8403 VS PAM8406

PAM8403 Datasheet

Download the PAM8403 datasheet PDF.

2D Model

Conclusion

The PAM8403 amplifier board may be small in size, but it packs a powerful punch when it comes to audio amplification. Its combination of high efficiency, low distortion, and compact design makes it a favorite among audio enthusiasts and engineers alike. Whether you're building a portable speaker, a headphone amplifier, or exploring the world of DIY audio projects, the PAM8403 is a reliable companion that ensures your audio sounds its best.

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