Power amplifier help

[kahafeez]

Hi people, i need to make a power amplifier for the following application. plz suggest me a simple as possible power amplifier which works in the audio range that is from 20Hz to 20KHz bcz my application works on 40KHz and 50KHz. i just need this plz help. thanks. and with the least components plz. the power amplifier i need should have a gain of 30dB.... and also tell me that how should i calculate the power of my FSK signal as shown in the attached image?

 

[silvarblade]

Hi people, i need to make a power amplifier for the following application. plz suggest me a simple as possible power amplifier which works in the audio range that is from 20Hz to 20KHz bcz my application works on 40KHz and 50KHz. i just need this plz help. thanks. and with the least components plz. the power amplifier i need should have a gain of 30dB.... and also tell me that how should i calculate the power of my FSK signal as shown in the attached image?

if your application works from 40k-50k then why you need amplifier for 20-20k?

 

[elnino86]

Hai kahfeez,maybe you should brief us your project because it a little bit confusing here.

20Hz to 20KHz bcz my application works on 40KHz and 50KHz.

 

[RadioRon]

To generate the signal, you can choose several methods. Two come to mind. One is to use a single bit output of the 8051 and toggle it at 40KHz or 50 KHz under software control. This would generate a rectangular waveform, and to clean it up to nearly a sinusoid you can add a simple low pass filter at the output before the power amp. Another method is to use a CD4046 phase locked loop, or rather, the VCO portion of that IC. You can have it oscillate at 40 to 50 KHz with an FSK input and just feed your binary data to it. It will also generate a rectangular waveform, but this can be cleaned up with a filter.

Many audio power amp kits are available and I would think most of them will work up to 50KHz. There are many audio power amp ICs that are easy to use, like this one:https://www.electro-tech-online.com/custompdfs/2008/12/LM384.pdf which has a voltage gain of 34 dB. You only need to attenuate the input a slight bit to trim the gain to 30 dB.