Stereo Audio Amplifier 50w x 2

Jose can you explain me how to power lm1875 with transformer? how many VoltAmperes must have for reach 20 W in a dual alimentation 25-0-25?

The voltage applied to the amplifier is limited by the design of the external power supply, while the maximum current passed by the output devices is usually limited by internal circuitry to some fixed value.beyond the power supply voltages applied to the amplifier. This can cause degradation of the output transistors or catastrophic failure of the whole circuit. The standard protection for this type of failure mechanism is a pair of diodes connected between the output of the amplifier and the supply rails. These are part of the internal circuitry of the LM1875, and needn't be added externally when standard reactive loads are driven. he LM1875 must always be operated with a heat sink, even when it is not required to drive a load. The maximum idling current of the device is 100 mA, so that on a 60V power supply an unloaded LM1875 must dissipate 6W of power. representation of the behavior of the LM1875 with various power supply voltages and resistive loads. As an example, if the LM1875 is operated on a 50V power supply with a resistive load of 8ohm, it can develop up to 19W of internal power dissipation.

hello, well, in the circuit I have not specified that It was for a particular model. I put in the reference these examples. Today, there are the possibility of having an integrated power. if you want to get some information from a particular model can found it in the oficial web

I can not clarify more because I've never used this model integrated in reality, only in simulators

V= √ 2 Rl Po = 17,88 V I= √ (2Po) / Rl = 2,23 A

39,87- 20 = 19.87 w in thermal dissipation

Thank you

If you want to mount on PCB You must take into account the track width, copper thickness and temperature.