What Is the PAM8403? Class-D Stereo Amplifier and Uses
The PAM8403 is an efficient class-D stereo audio amplifier (2×3 W). It runs from 5 V and needs no heatsink thanks to its high efficiency; it is the standard chip of USB/battery speaker modules. Being class-D it heats far less than linear amps like the LM386/TDA. The output is BTL — do not connect the speaker's negative to ground.
The PAM8403 is an efficient class-D stereo audio amplifier (2×3 W). Thanks to its high efficiency it needs no heatsink and runs from 5 V; it is the standard chip of tiny audio modules. For the concept, see what is an audio amplifier.
What is the PAM8403 used for?
USB speakers, portable/battery audio, toys and DIY Bluetooth speakers. Being class-D it heats far less than linear amps like the LM386 and TDA, extending battery life.
Connection (module)
Input: L/R + GND (audio source); Output: L+/L−, R+/R− (speakers); Supply: 5 V, GND. The output is bridge-tied (BTL), so the speaker terminals are not connected to ground.
Specifications
| Parameter | Value |
|---|---|
| Type | Class-D stereo amp |
| Power | 2 × 3 W (at 4Ω) |
| Supply | ~2.5–5.5 V |
| Efficiency | High (no heatsink) |
Watch out
The output is BTL (bridged); do not connect the speaker's negative terminal to ground. For class-D switching noise, supply filtering and good layout matter.
Equivalents
- PAM8302: a mono class-D (2.5 W).
- TPA3116: a much higher-power class-D.
- MAX98357: a class-D with I2S digital input.
Find it in our catalog
Use the PAM8403 search.