It is a Digital Amplifier 3W+3W Dual-Channel Audio Amplifier Board, Input Voltage: DC 3.6v~5.5V(Support 5V USB Power Supply) Suitable for for MP3/4/Mobile Phone/laptop external speakers etc
> Efficient digital amplifier chip, Built-in standby electronic switch, built-in high-gain buffer amplifier, built-in short circuit protection.
> Input Voltage: DC 3.6v~5.5V (the chip will burn out if more than 5.5V.)
> Output power: 3W +3 W (4 ohms)
> Signal to Noise Ratio: 90dB
> Efficiency:> 90%
> Maximum closed-loop gain:24DB
> positive and negative power supply can not be reversed, the supply voltage can not exceed 5.5V, or it would burn out the IC.
> On-chip high-gain buffer, can not change any component. Improper parameters would lead to IC damage.
> Please try to use the input line with shield wire, to removing clutter and current sound.
> CMOS BTL Driver Output, Left and right negative of speakers can not be connected together, 4 speaker wire is completely independent, Not allow connect together.
> if use with computer, powered by the computer USB, that would caused current sound. because the audio and USB common ground, so the current sound is unavoidable