TL071 vs LM386

Thread Starter

underground9

Joined Dec 13, 2011
7
I dont know much about amplifier ICs but what are the key differences between TL071 and LM386??

Any links to read up and etc.. would be a great to :)
 

MrChips

Joined Oct 2, 2009
19,382
The TL071 is very different from LM386 and you would not interchange the two in any given application. The TL071 is a low noise amplifier intended to increase the voltage of a weak signal, for example, a microphone or guitar pickup.

The LM386 is a low wattage power amplifier intended to drive a small loud speaker. This is used as the output stage of a low power audio amplifier, for example if you want to drive your PC speakers or the output of an MP3 player.
 

Thread Starter

underground9

Joined Dec 13, 2011
7
I understood that they are completely different from each other. My question lies in so what are the key differences between the two
 

MrChips

Joined Oct 2, 2009
19,382
Well, didn't I already explain? Then I'm not communicating well at all. In that case the technical differences would be found by comparing the specifications sheets.
 

Thread Starter

underground9

Joined Dec 13, 2011
7
what about physical properties.. such as the input they can take.. what there made from..i understood what you explained above but im looking to go into more detail
 

MrChips

Joined Oct 2, 2009
19,382
what about physical properties.. such as the input they can take.. what there made from..i understood what you explained above but im looking to go into more detail
The physical properties are the same. They are usually made from the same materials, silicon dioxide, boron, phosphorus, metal wires and bonded in plastic. The transistor processes may differ. One uses field effect transistors (FET) and the other uses bipolar junction transistors (BJT).

The input parameters are different. One has very high input impedance.
The output parameters are different. One has very low output impedance.
The noise performance is also different.
These are stated in their respective data (spec) sheets.
 

Thread Starter

underground9

Joined Dec 13, 2011
7
thanks but im finding it hard to read and understand them as its my first time reading them thats why im asking for help.
 
Last edited:

MrChips

Joined Oct 2, 2009
19,382
Learning to read data sheets is an important step in becoming a competent electronics designer. There are no shortcuts.

I don't have the time now but I will return and give you some tips. For the time being, take a look at the spec sheet for TI LM386 (this is a pdf download):

http://www.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=lm386&reg=en&fileType=pdf

The parts you always read are

  • General Description
  • Features
  • Applications
- all on the first page

and the

  • Application Notes
  • Application Hints
  • Design Notes
  • Design Examples
found later in the data sheets.
 

Audioguru

Joined Dec 20, 2007
11,251
The TL071 is an opamp with a voltage gain at DC and low frequencies of 200,000. It uses external negative feedback resistors to reduce its gain to a useable amount. Its minimum load is about 2000 ohms. It has very low distortion and low noise.

The LM386 is a little power amplifier with a voltage gain of 20 because it has negative feedback resistors built-in. Its load is a speaker that is 4 ohms to 16 ohms and higher.
Its distortion is fairly low and its noise is audible at low signal levels.
 
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