PAM8403 2×3W Class-D stereo amplifier module — 5V USB powered

The PAM8403 is a compact Class-D stereo audio amplifier module capable of delivering 2×3W of output power from a single 5V USB supply. Its filterless architecture eliminates the need for output LC filters, making it ideal for space-constrained DIY audio projects. With high efficiency and low EMI, it produces clean, crisp audio from any stereo source — perfect for portable speakers, Arduino audio projects, and Raspberry Pi sound systems.

Key Specifications:

• Amplifier IC: PAM8403
• Topology: Class-D (filterless)
• Output power: 3W + 3W (stereo, at 5V into 4Ω)
• Supply voltage: 2.5V – 5.5V (5V USB recommended)
• Supply current: ~1A max at full power
• THD+N: <0.1% at 1W output
• SNR: 80dB
• Efficiency: up to 90%
• Speaker impedance: 4Ω – 8Ω
• Input: stereo audio (3.5mm or direct wire)
• Onboard: power LED, volume potentiometer (on some variants)
• Dimensions: ~20mm × 20mm (compact module)

Pinout:

• VCC, GND: 5V power input
• L+, L−: Left speaker output (differential)
• R+, R−: Right speaker output (differential)
• Left IN, Right IN: Stereo audio input

Compatible With:

• Arduino Uno, Nano, Mega (audio output via DAC or PWM)
• Raspberry Pi (3.5mm audio jack)
• ESP32 with DAC output
• Any 3.5mm stereo audio source (phone, PC, MP3 player)
• 4Ω and 8Ω speakers

Applications:

• DIY portable Bluetooth speakers
• Arduino and Raspberry Pi audio projects
• Desktop mini speaker systems
• Intercom and announcement systems
• Retro gaming console audio
• IoT voice output devices

Note: This is a filterless Class-D amplifier — use shielded speaker wires and keep leads short to minimise EMI. Do not connect to high-impedance headphones directly.