Structured on the IC TDA 1521, this straightforward stereo audio amplifier design uses just a few extra passive components and produces an impressive 12 + 12 watts of sound output.
Main Characteristics
All of the integrated circuit's built-in functions, such as intelligent mute, overload, and overheat safeguards, are included in an amplifier circuit.
The stereo audio amplifier circuit shown here, which uses IC TDA 1521, is incredibly easy to assemble, has very few auxiliary parts, and can provide 12 + 12 watts of high-fidelity music power.
You may use your phone or a CD player as the input. In order to achieve the necessary stereo specifications. Constructing a stereo audio amplifier typically involves taking a couple of mono amplifiers and combining their inputs, common ground, and supply.
But these circuits often wind up being excessively big, because doubling the number of similar modules only creates the entire thing twice, which doubles the overall price.
However, a lot of single chips with integrated twin amplifier blocks are readily accessible on the market, making them incredibly small and elegant.
The TDA1521, a dual high fidelity power amplifier chip housed in a 9-pin plastic encapsulation, is one example of such an integrated circuit.
The chip's robust characteristics make it ideal for usage with power supply that aren't too smooth.
Construction Tips
Before we go into how to build a basic stereo amplifier with this integrated circuit, let's have a look at some fascinating features of the device.
With two supply voltages of approximately sixteen volts, the TDA1521 essentially operates at maximum efficiency and can push up to 12 watts of music through a pair of 8 ohm loud speakers.
The amplifier's gain is set and internally adjusted at 30 dB with a 0.2 dB margin. This guarantees a pleasant gain balance between its two channels.
The chip has a unique built-in feature that mutes music. Whenever the supply voltage drops under +/- 6 volts, this characteristic allows the IC to disable its non-inverting inputs, even though the amplifier is still properly driven at this point.
The aforementioned characteristic eliminates needless clicking sounds from the circuit when turning it on and off.
Short Circuit and Overload Protection
The IC's output is well shielded from overloads and unintentional short circuits.
In order to prevent harm from overheating, the IC also has a thermal runaway prevention feature; nonetheless, at high ambient temperatures, the IC may shut down.
Because of this, it is advised that whenever the output is connected to an 8 Ohm load at +/- 16 volts supply, the integrated circuit be fitted onto a 4K/W heatsink.
It should be noted that the exterior metal tab covering the IC and pin #5 of the IC are interconnected inside.
Parts List
- Resistors are 1/4 watt 5% CFR
- 10 Ω = 2
- Potentiometer 100 k = 2
- Capacitors are PPC 100 V, unless specified.
- 220 nF = 2
- 22 nF = 2
- 100 nF = 1
- Electrolytic 2200 µF / 50 V = 1
- Bridge rectifier diodes 1N5402 = 4
- Transformer 16-0-16V 3 amp = 1
- Loudspeaker 20 watts 8 ohm = 2
Technical Specifications
Some intriguing specs for this stereo amplifier chip are included in the following data:
At 12 watts, the total harmonic distortion is 0.5%.
The Quiscent Current Drain is below 40 milliamperes.
Gain Balance is around 0.2 dB.
The rejection of supply ripple is around 60 dB.
At 70 dB, the channel separation is
20 mV is the output offset voltage.
Power Bandwidth: 20–20,000 Hz at 3 dB.
Circuit Operation:
The stereo amplifier circuit displayed is quite straightforward and practically easy to understand.
It is evident that this stereo audio amplifier takes minimal hardware to function as a fully functional stereo amplifier.
Amazingly, this small equipment can produce high-quality stereo music using merely a resistor/capacitor combination to perform frequency adjustment and a couple of input DC filtering capacitors.
This stereo audio amplifier's entire unit is readily assembled on an ordinary board, and the whole thing, together with the power supply, may be housed within a robust aluminum enclosure.
Whether it’s your CD player or your cell phone, it will convert every bit of it into a heart throbbing true pulsating stereo output.