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Design >> Analog Design >> increase power efficiency in an amplifier circuit
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Message started by mustakhim on Mar 9^th, 2010, 4:20am

Title: increase power efficiency in an amplifier circuit
Post by mustakhim on Mar 9^th, 2010, 4:20am

hye guys,

I'm builiding an amplifier circuit using resistors and OPAMP(LM741). I already got everything about it, but I'm also asked to waste as little power as possible. Is there any solution for this. It seems like a very stupid question. I'm new to designing analog circuit.

Thanks in advance for any help.

Title: Re: increase power efficiency in an amplifier circuit
Post by loose-electron on Mar 9^th, 2010, 2:13pm

You are doing a board level design with an op-amp chip?

Hmmm...

The 741 has been around since before most people here were born. I would start by looking into a modern op-amp that does not waste a lot of power.

do some component searching:
http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_homepage_link=hp_ProductIndex&lang=en&site=US&keywords=

Go here:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=2556125&k=opamp

That's a start. Beyond that, need to know more about what you are trying to design.

Title: Re: increase power efficiency in an amplifier circuit
Post by mustakhim on Mar 9^th, 2010, 2:37pm

I should use the LM741. It is the requirement. The purpose is not to make a fully power efficient circuit, but it only want to reduce the power consumption. Got any idea on how to do it? Thanks

Title: Re: increase power efficiency in an amplifier circuit
Post by vivkr on Mar 10^th, 2010, 3:12am

mustakhim wrote on Mar 9^th, 2010, 4:20am:

That's not as stupid as you might think, although it would have been easier if you could atleast choose a 741 clone from another vendor. Is this for a university project or what?

Anyway, as the 741 has a push-pull output stage, the power consumption depends on the load it is driving. Depending on your specification, you should try to use the largest resistors. And maybe the feedback network can be made with capacitors as the active element and some large R to set the bias point in case your amp does not need to cover DC.

However, if power is really very critical and this is not just a university project or so, then you should be able to argue and convince whoever is making you work solely with LM741s to allow other opamps to be used. Otherwise, it would be really stupid, yes!

Vivek

Title: Re: increase power efficiency in an amplifier circuit
Post by mustakhim on Mar 10^th, 2010, 4:20am

this is a uni project, I just found out that we can use LM324 . Does it more power efficient than LM741?