chip PAM8403 ,. 3W pure digital high-power Class D for discharge, efficiency up to 90%. Super mini digital amplifier board, obtained at 10 years high efficiency digital amplifier, 5V power input, ultra-thin board [3 x 2] 6W can be very easy to put a small slit plastic box or other device, the build as MP3 / 4 or notebook external speakers, and other small, as you imagine, the power supply is recommended to take the USB or 5V power supply with a single lithium.
"Advantage": 10 years of the high efficiency digital amplifier chip, internal output cessing circuit, eliminating the conventional LC network, lower than the EMI by LC value! Maximum power output at a lower voltage, super power, built-in standby electronic switch, built-in high-gain buffer amplifier, built-in short circuit tection. "Power": 3.6 to 5.5V, single-cell lithium-powered USB or ap priate, may also be four 1.2V batteries, Transformer power supply must add 5V regulator circuit, the chip will burn more than 5.5V.
Power supply: DC?DC?: 3.6v-5.5V
Output power: 3W + 3W?4 ohm?
1: positive and negative power supply can not be reversed, the power supply voltage can not exceed 5.5V, these two violations could result in IC damage.
2: on-chip high-gain buffer, the board can not change any component parameters do not meet the parameters will result in IC damage.
3: Try to use the input line with shield wire, can play a role in immunity, eliminate clutter current sound.
4: cmos output tube BTL drive mode, the speaker can not be negative about together, that is connected to the speaker four lines are completely independent, does not allow total access!