Title :
Advances in active-feedback frequency compensation with power optimization and transient improvement
Author :
Lee, Hoi ; Mok, Philip K T
Author_Institution :
Dept. of Electr. & Electron. Eng., Hong Kong Univ. of Sci. & Technol., China
Abstract :
This paper presents a low-power stability strategy to significantly reduce the power consumption of a three-stage amplifier using active-feedback frequency compensation (AFFC). The bandwidth of the amplifier can also be enhanced. Simulation results verify that the power dissipation of the AFFC amplifier is reduced by 43% and the bandwidth is improved by 32.5% by using the proposed stability strategy. In addition, a dynamic feedforward stage (DFS), which can be embedded into the AFFC amplifier to improve the transient responses without consuming extra power, is proposed. Implemented in a 0.6-μm CMOS process, experimental results show that both AFFC amplifiers with and without DFS achieve almost the same small-signal performances while the amplifier with DFS improves both the negative slew rate and negative 1% settling time by two times.
Keywords :
CMOS integrated circuits; active filters; feedback amplifiers; power amplifiers; AFFC amplifier; CMOS process; active feedback; active-feedback frequency compensation; amplifier bandwidth; dynamic feedforward stage; low-power stability strategy; multistage amplifiers; negative 1% settling time; negative slew rate; power consumption reduction; power dissipation; power optimization; small-signal performances; three-stage amplifier; transient improvement; transient responses; Bandwidth; CMOS process; Capacitors; Energy consumption; Feedback; Frequency response; Power amplifiers; Power dissipation; Stability; Topology; Active feedback; DFS; amplifiers; dynamic feedforward stage; frequency compensation; low-power stability strategy; multistage amplifiers;
Journal_Title :
Circuits and Systems I: Regular Papers, IEEE Transactions on
DOI :
10.1109/TCSI.2004.834514
