5V DC Mini Class D PAM8403 USB Power Amplifier Board

5V DC Mini Class D PAM8403 USB Power Amplifier BoardThis miniature yet powerful audio amplifier module utilizes the highly efficient PAM8403 Class D amplifier IC, delivering robust stereo sound from an extremely compact form factor, consequently making it ideal for portable audio devices and space-constrained electronics projects. Designed to operate directly from a standard 5V DC supply, it features a convenient Micro USB input port for power, allowing users to easily drive it from a computer, power bank, or standard USB charger. The Class D architecture ensures exceptional power efficiency, significantly reducing heat generation compared to traditional Class AB amplifiers, therefore making it perfect for battery-powered applications. Furthermore, its capability to drive two speakers with up to 3 watts per channel makes it a versatile solution for prototyping and embedding into custom enclosures. However, users must ensure the input power quality is clean and stable to prevent audible noise or distortion in the output signal. Consequently, this module provides an excellent balance of high performance, low power consumption, and minimal size for professional audio integration.

Key Features

• High-Efficiency Class D: Utilizes the PAM8403 IC for low heat generation and maximized battery life.
• Micro USB Power Input: Offers convenient and standard power input from any 5V USB source.
• Stereo Output: Provides two independent audio channels for full stereo sound reproduction.
• High Output Power: Capable of delivering up to 3W + 3W into 4Ω loads, suitable for small speakers.
• Filterless Design: Simplifies circuit design and reduces component count without compromising audio quality.
• Volume/Mute Control Points: Features dedicated pads (V+/V-) for external analog volume control and a separate mute pin.

Technical Specifications

• Power Supply Voltage (VCC): 2.5V DC to 5.5V DC (Nominal 5V).
• Amplifier IC: PAM8403.
• Output Power (Max): 3W + 3W into 4Ω speakers @ 5V, or 1.5W + 1.5W into 8Ω speakers.
• Efficiency: Typically ≥ 90% at 5V, maximizing power conversion.
• Total Harmonic Distortion (THD): ≤ 10% (at max output power), and ≤ 0.1% (at 1W output), therefore providing clean audio at moderate volumes.
• Signal-to-Noise Ratio (SNR): Typically 80 dB.
• Operating Temperature Range: −20°C to +85°C.
• Input Impedance: High impedance ≈ 10 kΩ.

Mechanical Specifications

• PCB Material: FR4 standard green PCB.
• Mounting: Features solder pads along the perimeter for flexible installation or direct wiring into enclosures.
• Connectors: Micro USB female port for power; Solder pads for speaker and audio input.
• Component Type: Predominantly Surface Mount Technology (SMT) for ultra-compact size.

Dimensions

• Module Size: ≈ 18.5 mm × 18.5 mm (L x W).
• Height (Max, including IC): ≈ 3 mm.
• Weight: ≈ 1.5 g (Extremely low weight).

Pinout and Wiring

• VCC/GND (Micro USB): Provides 5V DC input power.
• L+, L− / R+, R−: Speaker output terminals (L for Left, R for Right). Connect to 4Ω or 8Ω speakers.
• IN L, IN R, GND: Audio input terminals (Left, Right, and common ground). Connect to audio source (e.g., phone jack, microcontroller DAC).
• V+/V− (Optional): Solder pads for connecting an external potentiometer for analog volume control.

Datasheet Reference: Download Datasheet

1. • PAM8403 Class D Stereo Amplifier Datasheet

Commonly Used in

• DIY Portable Bluetooth Speakers
• Microcontroller Audio Output Projects (e.g., Arduino, ESP32)
• Small Retro Gaming Consoles
• Custom PC Monitor Speakers
• Hobbyist Radio Systems

Applications

• Engineers integrate this module into battery-powered sound devices where efficiency and minimal footprint are critical design constraints.
• It serves as the final stage amplifier in custom alert and notification systems, increasing the volume of digital tones.
• Consequently, hobbyists attach it to microcontroller projects (like an MP3 player shield) to provide robust audible output.
• Therefore, developers utilize its stereo capability for immersive audio feedback in small scale prototypes and desktop equipment.
• Its size makes it ideal for embedding audio capability into existing, non-audio electronic devices.

Equivalent Models

• PAM8406 Module: A slightly higher power version offering similar Class D architecture.
• TDA7498 Module: A much larger, high-power Class D amplifier module for comparison.
• LM386 Modules: Older, less efficient Class AB modules that serve a similar low-power amplification function.

Package Includes

• 1 x 5V DC Mini Class D PAM8403 Stereo Amplifier Board