Type D power amplifier with very amplification efficiency. The sound quality is not affected by temperature rise and no heat sink is required. Power options and compatibility Can be powered by 5V USB from a computer, a 5V phone charger, or a lithium battery. Compatible with 4 ohm loads and 5V supply for stereo output. Performance and specifications efficiency of 90 percent. Delivers 3 W per channel (left channel) and 3 W per channel (right channel) when used with a 4 ohm load and a 5V power supply. PAM8403 mini type module size: 2.3 x 1.8 cm (0.9 x 0.7 in); compact enough to fit in small spaces of many digital products, while maintaining amplification efficiency. Applications and use scenarios USBpowered portable speakers or compact multimedia devices that run directly from a 5V source such as a power bank or USB charger. Embedded audio for small digital projects, including microcontrollerbased audio gadgets or Raspberry Pi accessories, where space and power efficiency are important. Educational electronics kits or DIY audio projects that demonstrate class D amplification in a small, lowpower package. Key attributes Function: stereo power amplifier with Class D efficiency, suitable for 4 ohm loads at 5V. Compatibility: USB 5V, phone charger 5V, lithium battery; compact PAM8403 mini module. Size: 2.3 x 1.8 cm (0.9 x 0.7 in); easy to integrate into tight spaces. Material and construction: compact efficiency module designed for reliable audio performance. Performance: amplification efficiency, strong output for compact 5Vpowered applications.