The LA4550 is a dual power amplifier integrated circuit that is often used to boost low frequency sounds in audio systems.
It is popular in portable speakers, radio circuits and other compact audio gadgets because it is easy to use and very efficient.
This IC can produce up to 4 watts of output power, which makes it perfect for smaller audio projects.
The IC LA4550 has some cool features!
It uses very little power when it is not doing anything, has two channels for stereo sound or to work in bridge mode, does a great job of reducing noise from power fluctuations, keeps the sound from each channel separate and makes almost no noise when you turn it on or off.
Circuit Working:
Parts List:
| Component Type | Specification | Quantity |
|---|---|---|
| Resistors | ||
| 1Ω 1/4 watt | 3 | |
| Capacitors | ||
| Ceramic | 0.1µF | 4 |
| Electrolytic | 100µF 25V | 5 |
| Electrolytic | 470µF 25V | 3 |
| Semiconductor | ||
| IC | LA4550 | 1 |
| Speaker | 8Ω | 1 |
The circuit diagram above shows a single channel audio amplifier that uses the LA4550 integrated circuit.
It runs on 12V DC and can power an 8 ohm speaker delivering 4 watts of sound.
The IC LA4550 takes the audio input and boosts it to drive the speaker.
The audio signal goes into pin 4 of the IC through a coupling capacitor called C4, which blocks any DC signals and lets only the audio signals through.
Inside the IC the weak audio signal gets amplified.
Components like C2 and R1 help with feedback and keeping everything stable.
The amplifiers gain is set by the internal design and can be changed with feedback resistors and capacitors.
Capacitors C1, C3 and C11 help stabilize the power supply and reduce noise.
The boosted audio signal is sent to the 8Ω speaker through another coupling capacitor C9 which also blocks DC ensuring that only the audio signal reaches the speaker.
The 8 ohm speaker then turns the electrical audio signal into sound waves.
Formulas with Calculations:
The formulas with calculations are mentioned below for 4W Audio Amplifier Circuit using IC LA4550
Output Power:
P = V^2 / R
where,
- P is the power in watts
- V is the peak voltage determined by the supply voltage
- R is the speaker resistance
Example: For a 12V supply and an 8 ohm speaker:
P = (12)^2 / 8 = 4W
Capacitor Selection:
fc = 1 / (2πRC)
where,
- fc is the cutoff frequency
- R is the load resistance for 8 ohms speaker
- C is the capacitance
Example: If fc is set to 20Hz:
C = 1 / (2π × 8 × 20) = 0.99 µF
Power Dissipation:
PDISS = VCC × IQ
where,
- IQ is the quiescent current from the IC datasheet
How to Build:
To build a 4W Audio Amplifier Circuit using IC LA4550 following are the connections steps to follow:
- Gather all the components as mentioned in the above circuit diagram.
- Connect pin 2 of IC LA4550 to one end of 8Ω speaker through capacitor C10.
- Connect pin 2 of IC LA4550 to pin 3 through capacitor C3.
- Connect pin 4 of IC LA4550 to pin 9 through capacitors C3 and C6, connect from pin 4 capacitor C5 and resistor R2 to GND.
- Connect pin 6 of IC LA4550 to pin 7 through capacitor C4
- Connect pin 8 of IC LA4550 to audio input.
- Connect pin 10 of IC LA4550 to pin 11 through capacitor 10.
- Connect pin 11 of IC LA4550 to other end of 8Ω speaker through capacitor C9, connect from pin 11 capacitor C8 and resistor R3 to GND.
- Connect pin 12 to +12V DC positive supply, connect capacitors C11 and C12 from positive supply and GND
Conclusion:
The 4W Audio Amplifier Circuit using IC LA4550 is a small and effective option for low power sound projects.
It has a simple circuit and uses parts that are easy to find, making it perfect for both hobbyists and professionals.
This amplifier produces clear audio with very little distortion, which is great for small speakers and sound systems.
If you follow the circuit diagram, do the calculations and stick to the building instructions you can create a 4W audio amplifier using the IC LA4550 chip.
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