single supply op-amp

Discussion in 'General Electronics Chat' started by jameselder232, Nov 3, 2010.

  1. jameselder232

    Thread Starter Member

    Oct 31, 2010
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    Hi, I'm now looking to use a single supply op-amp with a 4.5V supply. Now my simulation software doesn't have any single supply op-amps, its quite basic in that respect.

    I was just wondering with these single supply op-amps namely the 358, do they amplify both the positive and negative parts of the wave? And do they amplify both parts to the maximum 4.5V before clipping occurs, or is it ±2.25V as with dual supply op-amps.

    Thanks,
    James
     
    Last edited: Nov 3, 2010
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
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    Single supply amplifiers - like dual supply op-amps have both a common mode input range and an output swing range.

    Single supply op-amps often have an input common mode range which includes supply ground.

    As long as the input signal stays within the common mode range and the amplifier gain is correctly adjusted, the output will swing without any clipping.

    It would be unlikely that the output would swing to the positive supply rail but it can possibly swing to the supply ground rail.
     
  3. t_n_k

    AAC Fanatic!

    Mar 6, 2009
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    The LM358 specs suggest the aforementioned capability. The output positive swing is limited to +ve supply rail less 1.5V.

    So with a 4.5V supply the output could notionally swing between 0V (ground) and 3V.
     
  4. Wendy

    Moderator

    Mar 24, 2008
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  5. Audioguru

    New Member

    Dec 20, 2007
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    The LM358 is very old and was one of the first low power opamps. It has low power because it does not have enough bias current for its output transistors so they produce 3% of crossover distortion. The low power also reduces its full output bandwidth to only 2kHz.
     
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