The increasing number of battery-operated devices asks for more low-power electronic circuits. A major cause of current consumption are the bias currents. Thus designing circuits having no bias currents may lead to considerable reductions in the power consumption. This inherently implies that we have to deal with the nonlinear behavior of devices. Here the design of a low-voltage low-power negative-feedback amplifiers with a class-B output stage is described. The key issue in the design is the description of the dynamics of the amplifier by the linear time-varying approach. This uses a time-varying small-signal model of nonlinear circuits and enables a generalization of the traditional pole-zero concept. The designed amplifier is capable of driving 1 mA through a piezoelectric load (14 nF). The stand-by current varies from 40 /spl mu/A to 100 /spl mu/A.
['A. van Staveren', 'T.H.A.J. Cordenier', 'F. C. M. Kuijstermans', 'P. van der Kloet', 'F. L. Neerhoff', 'C.J.M. Verhoeven', 'A.H.M. van Roermund']
The linear time-varying approach applied to the design of a negative-feedback class-B output amplifier