The construction of a 12 watt amplifier circuit with the IC TDA2030 is discussed in this article.
One popular integrated circuit for audio amplification is the TDA2030.
Its a pentawatt monolithic audio power amplifier designed for the use of low frequency class AB amplifier.
Circuit Working:
Parts List:
| Category | Component | Value/Type | Quantity |
|---|---|---|---|
| Resistors | 22k 1/4 watt | 1 | |
| 680k 1/4 watt | 1 | ||
| 1.8Ω 1/4 watt | 1 | ||
| 4.7k 1/4 watt | 2 | ||
| Potentiometer 22k log | 1 | ||
| Capacitors | |||
| Ceramic 100nF | 1 | ||
| Electrolytic 2.2µF 25V | 1 | ||
| Electrolytic 10µF 25V | 1 | ||
| Electrolytic 1000µF 25V | 1 | ||
| Electrolytic 100µF 40V | 1 | ||
| Semiconductors | Integrated Circuit TDA2030 | 1 | |
| Speaker 8Ω | 1 |
This TDA2030 amplifier circuit can generate an output power of about 8W rms into an 8 ohm speaker while keeping low distortion of less than 0.1 percent THD when powered by a 24V power supply.
The output power rises to around 12 watts rms when used with a 4 ohm speaker and the distortion level is almost tripled but still falls within the lower range.
The circuit can operate at lower output voltages such as 9V but the maximum output power shall reduce.
This circuit that includes a TDA2030 integrated circuit is a modern devices that operates more quickly and simply than most of its earlier earlier generations.
Calculations and Formulas:
The voltage gain of a non-inverting amplifier circuit can often be calculated using this formula which is particularly useful for operational amplifiers using particular designs:
Gain = (1 + R3 / R2)
where,
- Gain is calculated by dividing the input voltage (Vi) by the output voltage (Vo) of the op-amp circuit.
- The resistance value R3 connects an inverting input terminal resistor to the output of an op-amp.
- The resistance value R2 is what keeps the inverting input terminal of the op-amp away from ground.
Calculations:
The resistor that connects to the ground and the inverting input has a resistance of 4.7 kilohms which is shown by the R2 resistor value of 4.7k.
R3 4.7k represents the 4.7 kilohm resistance of the resistor that connects between the output and the resistor at the inverting input.
Using the formula:
R2 = 4.7k and R3 = 4.7k the gain becomes:
Gain = (1 + 4.7 kΩ / 4.7 kΩ) = (1 + 1) = 2
Meaning:
With these resistor choices the gain of this particular op amp circuit will be two increasing the input voltage by a factor of two.
In other words the output voltage will have double the amplitude of the input voltage if the operational amplifier operates within its linear range.
Key Points:
This formula addresses designs of non-inverting operational amplifiers.
For inverting systems the formula is slightly different.
It is expected in this simple method that the operational amplifier itself has a very large open loop gain perhaps which is unlimited.
This formula provides the possible advantage.
A number of variables including component tolerances and op amp features might lead the real gain in actual circuits to differ somewhat.
How to Build:
To build a Simple Amplifier Circuit using IC TDA2030 follow the following steps for connections:
Source of Power:
- The power supplies positive and negative terminals are connected to the correct TDA2030 pins.
- A dual power supply with a voltage range of ±12V to ±18V would be helpful.
Stage of Input:
- Connect pin 3 of the non-inverting input to the audio input signal.
- Pin 2 of the inverting input should be grounded.
- A high pass filter made up of R1 and C1 lowers the DC distortion and provides stability.
- For feedback R2 and R3 provide a voltage divider that adjusts the amplifiers gain.
- The formula above is used for calculating the gain which is (1 + R3/R2).
Output Stage:
- R4 provides stability and ensures proper biasing.
- C2 blocks any DC component from reaching the speaker.
- C3 and C4 are the part of the output filter network.
Speaker Connection:
- Connect the positive supply of the speaker to the OUT pin and the negative supply to the GND pin.
- To provide a clean output signal C3 and C4 help in filtering out any leftover AC components.
Conclusion:
The TDA2030 is used as a starting point in this simple amplifier circuit, component values might require to be modified based on what is needed.
Also the TDA2030 may require proper heatsinking especially if it is being used at higher power levels.
For more information and provided application circuits always see the TDA2030 datasheet.
References:
Design and implementation of a high performance AB-class amplifier using TDA2030