The PAM8403 is an ultra-compact, high-efficiency 2-channel x 3W Class D digital audio power amplifier board. It is widely used for DIY portable speakers, Arduino or microcontroller audio projects, and USB-powered sound systems.Technical Specifications

• Output Power: 3W + 3W (Dual-channel stereo into a 4 load at 5V).
• Operating Voltage: 2.5V to 5.5V DC (Highly compatible with 5V USB power or a single 3.7V Lithium-ion battery).
• Efficiency: Up to 90%, meaning it generates very little heat and requires no bulky heatsink.
• Architecture: Filterless Class D design allows direct speaker connection without external low-pass LC filters.
• Safety Features: Short-circuit protection, over-temperature shutdown, and under-voltage lockout.

Pin Configuration Guide

• Power Input: +5V (or VCC) and GND.
• Audio Input: L (Left Channel Input), R (Right Channel Input), and GND (Audio Ground reference).
• Speaker Outputs: Separate L+, L- and R+, R- pins to hook up individual 4 to 8 small speakers.

Critical Usage Warnings Do Not Share Speaker Grounds: The left and right channel “negative” (-) speaker outputs must never be connected together or wired to a common ground. Doing so will instantly destroy the PAM8403 IC.
Voltage Limits: Never exceed a 5.5V DC supply. Do not power the module using four standard AA dry cells without a regulator, as new batteries can exceed 6.0V and burn out the chip.
Connect Speakers First: Always connect the speaker loads before applying power to prevent chip damage.