2 watts Audio Amplifier Circuit with the TDA2822M IC

These 2 watts audio amplifier circuit is specially designed to consume little power and to be used with batteries or low voltage power sources. It can be used as a stereo amplifier in a multimedia system for a personal computer or as a low power portable amplifier using a 9V battery.

The heart of the circuit is the TDA2822M integrated circuit. This integrated circuit has an 8-pin mini DIP presentation. The TDA2822M has a low quiescent current, little distortion and can use a voltage source ranging from 1.8 to 15 V.

If you want a more powerful audio amplifier, check the 6 W Hi-Fi amplifier circuit or the 400 W stereo amplifier that use the STK4050 IC.

How does 2 watt audio amplifier circuit work?

The audio signal is applied directly to pins 6 and 7 of the integrated circuit through two networks of passive components. These two networks are:

• R2, C2 and potentiometer VR1
• R3, C3 and VR2 potentiometer

VR1 and VR2 potentiometers are the volume controls. VR1 controls the volume of the left channel. VR2 controls the volume of the right channel. The amplified signals are obtained from pins 1 and 3 respectively, one output for each channel.

The series capacitor-resistance arrangement in parallel with each speaker (Zobel network) is used for the purpose of correcting some instabilities of the amplifier due to phase variations caused by cables, and / or crossovers, etc., which sometimes occurs at frequencies greater than 10 Megahertz.

The circuit includes a red LED to indicate that it is working.

TDA2822M Integrated circuit (audio amplifier)

2 Watt Audio Amplifier Component List

• 1 TDA2822M integrated circuit (IC1)
• 1 1 ohm resistor (R1)
• 2 47 K resistors (R2, R3)
• 1 1 K resistor (R4)
• 2 4.7 ohm resistors (R5, R6)
• 2 x 47 K potentiometers (VR1, VR2)
• 5 x 100 uF, 25V Electrolytic Capacitors (C1, C5, C6, C7, C9)
• 5 x 100 nF capacitors (C2, C3, C4, C8, C10)
• 1 red LED
• 1 On – Off switch (SW)

One of the following two options is possible:

• A maximum power of 1 watt per channel is achieved using 2 miniature 8 ohm speakers, if the supply voltage is 9 V.
• A maximum power of 0.650 watts per channel is achieved using 2 miniature 4 ohm speakers, if the supply voltage is 5 V.