SNOA475F October   2016  – September 2020 LMV791

 

  1.   Trademarks
  2. 1Introduction
  3. 2What Parameters Should Be Tested?
    1. 2.1  Open-Loop Gain (AOL) and Phase Margin
    2. 2.2  Slew Rate
    3. 2.3  Common-Mode Rejection Ratio (CMRR) and Power Supply Rejection Ratio (PSRR)
    4. 2.4  Open-Loop Output Impedance (Zo)
    5. 2.5  Voltage Noise (en)
    6. 2.6  Current Noise (in)
    7. 2.7  Input Offset Voltage (VOS), Input Bias Current (Ib), and Quiescent Current (IQ)
    8. 2.8  Output Voltage Versus Output Current (Claw Curve)
    9. 2.9  Overload Recovery Time (tOR)
    10. 2.10 Common-mode Input Capacitance (CCM) and Common-mode Differential Capacitance (CDIFF)
    11. 2.11 Overshoot and Transient Response
    12. 2.12 Common-Mode Voltage Range (CMVR)
  4. 3Conclusion
  5.   Revision History

2 What Parameters Should Be Tested?

Macro models differ in their level of complexity. Much like data sheets, the models should emulate parameters that are relevant to applications in which the op amp is thought to be appropriate. For example if a rail-to-rail output op amp is used, then the user should be able to test and verify the output voltage versus the output current (claw curves). Likewise, a low noise amplifier should have a model that emulates at least the voltage noise among other modeled parameters.

Despite their differences, amplifier macro models have a lot in common; these parameters are of the greatest interest and they are usually the starting point of the simulation. Below is a list of these parameters along with the corresponding test circuits and the simulations, which may be downloaded here: AN1516 Test Circuits.