Amplifier DIY - with TDA1521 Audio Amplifier IC Homemade High Fuel Source Speaker

The TDA1521 launched by the Netherlands Philips is a two-channel high-fidelity generated IC with a wide operating voltage range, large output power, small distortion, and has a variety of protection circuits internally, and is stable and reliable. The power amplifier IC can be powered in both power supply, and a single power supply can be powered. Since the internal contained power amplifier circuit, the peripheral components are small, so use a TDA1521 can make OTL power amplifier according to the actual situation, OCL power amplifier And BTL amplifier, very suitable for beginners to do their own power amplifier. The following describes two OCL power amplifier circuits and OTL power amplifiers that use TDA1521 designed. Amplifier DIY - with TDA1521 Audio Amplifier IC Homemade High Fuel Source Speaker The TDA1521 uses a 9-legged column-packed package, and there is a short circuit and an overheat protection circuit, and has a switching static noise function (no noise when the power is turned on or disconnected). The IC has an operating voltage range of ± 7.5 ~ ± 20V, a quiescent current is 40mA, an input resistor 20kΩ, and a signal-to-noise ratio is 85dB. When the power supply voltage is ± 16V, the output power is 12 wx2 (RL = 8Ω, THD = 0.5%), or 15Wx2 (RL = 8Ω, THD = 10%). Since the OCL power amplifier circuit output does not contain an output coupling capacitor, its bass effect is better. This circuit can operate at ± 10 ~ ± 16V supply voltage. ▲ The OTL power amplifier circuit composed of TDA1521. If there is no dual power source in practice, the TDA1521 can be used as a single power supply. At this time, the 2,38 foot of the TDA1521 needs to be connected, and then passed through a 100μF electrolytic capacitor (i.e., the C3 in the figure), and the output terminal of the TDA 1521 is 4 Both the feet and 6 feet are connected to the horn by the output coupling capacitor. When the TDA1521 is used as a single power supply, the recommended operating voltage ranges from 16 to 32V. Since its output coupling capacitance is an electrolytic capacitor of thousands of μF, this OTL amplifier is inferior to the OCL power amplifier circuit shown above with the above figure in terms of processing low frequency signals. Amplifier DIY - with TDA1521 Audio Amplifier IC Homemade High Fuel Source Speaker ▲ single-line direct insert 9 foot packaged TDA1521. The above picture shows the TDA1521 of the single-column inserted 9 foot packages. There is also a TDA1521A, although it is also a single-column direct-in package, but its heat sink is different from the TDA1521, it needs attention when choosing. Amplifier DIY - with TDA1521 Audio Amplifier IC Homemade High Fuel Source Speaker ▲ TDA1521 composed of BTL amplifiers. Since the TDA 1521 contains two identical amplifier circuits, it is convenient to receive a BTL power amplifier circuit so that a larger power can be output at a lower supply voltage. • This BTL power amplifier composed of TDA1521 has a maximum output power of up to 30W. Precautions 1, TDA1521 self-heat sink cannot be grounded, so the external heat sink must be added between the TDA1521 self-heat sink and the external heat sink as an insulating (if the mica film is not added, and the additional heat sink is grounded, boot It is easy to damage TDA1521). 2, in the OCL circuit and OTL circuit described above, each non-poble capacitor uses a monolithic capacitor. 0.22 μF capacitors in parallel with 2200μF power filter capacitors, when soldering, it is close to the power pins of TDA1521.