Simple 100 Watt Amplifier Circuit using a Single IC

In this post we learn about a very simple yet robust single IC 100 watt power amplifier circuit which utilizes minimum number of components.

As one can witness virtually the entire amplifier circuit itself is processed within the LM12CLK integrated circuit which is actually an operational power amplifier. The IC is equipped with an output stage that is able to operate at impedance of even as low as 2 ohms and therefore obtain a reasonably robust 150W of power. In order to ensure security and stability of the circuit here we have designed to make the unit work with 4 ohm speakers and this gives us an RMS power of 100W.

Simple 100 Watt Amplifier Circuit using a Single IC

The coil or the inductor L in the output of the IC is formed by winding 14 turns of wire No. 18 with a 1 inch diameter without core. The distance between each of the turns is not too critical, so somewhat here and there will not affect the performance.

The transformer for the power supply must be rated to provide 24v + 24v of AC supply in its secondary with a minimum of  5A current for one stage (mono) or twice 10A for two stages (stereo). Although four numbers of 15A rectifier diodes could be incorporated to make the bridge rectifier unit, it is advisable to employ a metal rectifier bridge unit instead and fit it within the relevant heat sink.

Since the value of the resistance is odd the resistance of 1.1K must be kind of a precision resistor, MFR 1% or SMD. And also the resistance at the output (shown in parallel with the coil) must be rated at least 2W power.

The electrolytic capacitors indicated in this simple 100 watt single chip circuit must be rated at 50V or 63V.