Radioengineering (Jun 2013)
Voltage Differencing Buffered/Inverted Amplifiers and Their Applications for Signal Generation
Abstract
This paper presents some interesting new applications in the field of analog signal processing focused on signal generation. A novel modifications of recently developed and studied family of active elements, called voltage differencing buffered amplifier (VDBA) and voltage differencing inverted buffered amplifier (VDIBA) are discussed. Our attention is focused on simple application of active elements like dual output VDBAs (DO-VDBAs) and fully balanced VDBAs (FB-VDBAs), where one or two z terminals and always voltage outputs of both polarities are present. The last modification of VDBA allows additional electronic control of voltage gain in frame of active element except standard transconductance control. Discussed active elements were used to build very simple multiphase oscillators with minimal complexity as a simple non-tunable alternative to classical conceptions utilizing lossy integrators in phase-shifted loop. Linearly tunable quadrature differential mode (balanced) oscillator or balanced simple triangle and square wave generator were chosen as other useful examples. Features of proposed circuits are discussed and selected examples verified and evaluated by computer simulations with appropriate low-voltage TSMC 0.18 um CMOS technology models.
