Figure‐of‐Merit‐Based Area‐Constrained Design of Differential Amplifiers

Abstract

A new methodology based on the concept of figure of merit under area constraints is described for designing optimum performance differential amplifiers. First a figure of merit is introduced that includes the three performance parameters, namely, input-referred noise, differential dc gain, and unity-gain bandwidth. Expressions for these parameters have been derived analytically and finally arrived at an expression for the figure of merit. Next it is shown how these performance parameters vary with the relative allocation of the total available area between the input and load transistors. The figure of merit peaks at a certain value of relative area allocation in the range of 60% to 80% of the available area to the input transistors. The peak value of figure of merit is a function of area. However, it is independent of biasing current (and, therefore, power consumption) subject to the minimum current (and, therefore, a minimum power) required to keep all the transistors biased in the saturation region. The peak figure of merit and minimum power required to achieve the peak figure of merit are also plotted as a function of area. These analyses help in synthesizing optimal differential amplifier circuit designs under area constraints.

Symbiotic organisms search algorithm for optimal design of CMOS two‐stage op‐amp with nulling resistor and robust bias circuit

“…Both the organisms will take the advantages to survive inside the ecosystem using the mutualistic interaction. The new values of X i and X j are evaluated using (27) and (28), respectively…”

“…Mutual_Vector describes an interaction between the organisms (X i and X j ) and is defined in (29). In (27) and (28), the remaining parts indicate the mutualistic effort due to the organisms to improve their adaptation level into the ecosystem (highest level of adaptation is implied by X best ). If they provide better values of CF as compared to the previous solutions, then only the new solutions are accepted.…”

“…The SOS algorithm is used to optimise the . FOM [28] for this circuit is presented as …”