In this article, we are going to explain some Low Power Audio Amplifier. There is a multitude of low power Audio Amplifier Using IC (integrated circuits). I will show some quite common, easy-to-make, and generally low-cost. Most of these amplifiers are used by televisions, test and measurement equipment, old modems, etc.
At present, there is talk of sound equipment of “10,000 Watts PMPO” or more. Then someone may think that a 20-watt amplifier per channel is low power when in fact it is not because here we talk about real power or RMS. You should know that PMPO is not a real electronic measure.
Low-power amplifier projects are 1W, 2W, or less than 10 watts.
First I will present the popular LM380, widely used in televisions, communication radios, measuring equipment, modem, etc.
This integrated circuit is very flexible for the voltage, according to the manufacturer works well from 10 to 22 volts, delivering a power of up to 2.5 watts. I use it in projects for 12 volts.
This amplifier is similar to the LM380 but is much less power, reaching 1 watt than the LM386N-4,
the operating voltage ranges from 4 to 12 volts (LM386N-1, LM386N-3, LM386M-1, LM386MM-1)
Or from 5 to 18 volts the LM386N-4.
Diagram of the amplifier with LM386:
The gain of this amplifier is adjusted between pins 1 and 8
disconnected approximately 26dB, and with an electrolytic capacitor between the tips up to 46 dB. (10uF, positive pin1)
Most versions of the LM386 are of the order of 125 mW. Used quite a lot as an amplifier for hearing aids or as an output in error indicators, alert tones, and “buzzers”.
The TDA7235 is widely used in televisions, with a heat sink that can be used as a 4-watt amplifier.
The voltage is surprisingly flexible, it can be used from 1.8 volts to 24.
The TDA7267 is specially designed for televisions, with the gain set at 32 dB. Although the voltage is not as flexible as the previous one, it can work from 4.5V to 18V. With pin 3 (SVR) grounded the integrated circuit is at rest (stand-by)
Connection drawing of the TDA7267:
This integrated circuit in addition to the versatility of the power supply (1.8V to 15V), is double (stereo). Being ideal for projects or portable applications, trying not to exceed 1 watt per channel.
Connection drawing of the TDA2822M: (audio amplifier using ic)
The UTC2822H amplifier, the D2822N, and the TDA2822M are exactly the same in connections and the only difference found is that the UTC2822H can only work from 1.8V to 6V, and supports a maximum of 9 volts. While the D2822N does work from 1.8V to 15V.
There is also the TDA2822 which is 16 pins. (audio amplifier using it)
This integrated circuit can be used from 3 to 15 Volts, it can handle a maximum of 4 watts
(2W x 2) with the heat sink.
The electronic features are similar to the 8-pin TDA2822M amplifier but used 3 volts.
Connection drawing of the 16-pin TDA2822:
Both for this amplifier TDA2822 and for all others we must take into account a good ground connection to avoid oscillations that could damage them or produce unwanted noise.