Buffer with LF353

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welllll

New Member

• Aug 7, 2011

• #1

Hello Electro Tech users. I am an electronic student and i'd like to create a simple buffer with the LF353 opamp. My schematics is attached in this post. Could you please tell me why is this happening?

Cumps,
Well

 

Attachments

• buffer doesnt work.jpg

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ericgibbs

Well-Known Member

Most Helpful Member

• Aug 7, 2011

• #2

hi,
The LF353 is not really suited to single supply operation, especially at such a low supply voltage.
The output of the LF353 will limit at approx 1.5V to 2V less than the supply.

You need to get an OPA thats designed to work from a single low supply and has a rail to rail output range. eg: MCP6002

 

Ian Rogers

User Extraordinaire

Forum Supporter

Most Helpful Member

• Aug 7, 2011

• #3

Place a small value resistor from the output to ground (there has to be current flowing )

 

Attachments

• lf353.png

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W

welllll

New Member

• Aug 7, 2011

• #4

Ian i tried that scheme and it doesn't work =/. Output is always equal to 0.7 V.

 

ericgibbs

Well-Known Member

Most Helpful Member

• Aug 7, 2011

• #5

welllll said:

Ian i tried that scheme and it doesn't work =/. Output is always equal to 0.7 V.

Click to expand...

With a low single supply voltage the output will not go lower than approx 0.7V or higher than about 1.5V

The amplifier type is NOT suitable for that application.

 

W

welllll

New Member

• Aug 7, 2011

• #6

Thank you ericgibbs. I dont have a rail-to-rail output opamp with single suply but i've already ordered that MCP6002 from microchip =)