high current, low noise and distortion linear amplifier design

Discussion in 'General Electronics Chat' started by parmar, Nov 11, 2009.

  1. parmar

    Thread Starter New Member

    Nov 11, 2009
    Application: We are making a long range nanopositioning system with range 10mm and resolution 10nm. The mechanism is actuated by voice coil motor which needs a amplifier driver. The driver has to deliver high current (for range) with ultra low noise and distortion (for resolution).

    Specifications for amplifier circuit:
    1. Max current : 10A
    2. Bandwidth : 200Hz (my only hope to achieve other specifications!)
    3. Noise Floor : -110dB
    4. Total harmonic Distortion > 100dB

    Q) Is it possible to design an power amplifier circuit with such noise specifications?
    Q) Is using composite amplifier design in which the power opamp is preceded by a precision op amp can offer better noise and distortion performance from the overall circuit?
    Q) How can I simulate noise and distortion any op amp circuit? Is there a solution in PSpice?
  2. Audioguru

    New Member

    Dec 20, 2007
    The very best audio amps have distortion at 0.003% at full power which is -90dB.
    If you chop off all the high frequencies above 200hz then the distortion will be lower.