Feedforward compensation of the amplifier output stage for improved stability with capacitive loads

Leach, Jr. W.M.

doi:10.1109/30.2950

Cited by 5 publications

(1 citation statement)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, in any case, the design of the feedback loop has to be adopted if the load impedance shows a capacitive portion due to the then given additional phase shift. In this case, it would be more efficient to directly improve the output impedance of the current buffer stage using a feedforward compensation [8] or an inner feedback/feedforward corrector scheme as proposed in [9]. It has to be noted that, concerning the output impedance, the realization of the output stage using bipolar power transistors would probably be a better solution because of their higher transconductance as compared to MOSFET's.…”

Section: Linear Stage Design-output Impedancementioning

confidence: 99%

Basic considerations and topologies of switched-mode assisted linear power amplifiers

Ertl¹,

Kolar²,

Zach³

1997

IEEE Trans. Ind. Electron.

123

View full text Add to dashboard Cite

This paper presents a combined power amplifier system consisting of a linear amplifier unit with a switchedmode (class D) current dumping stage arranged in parallel. With this topology, the fundamental drawback of conventional linear power amplifiers-the high loss-is avoided. Compared to a pure class D (switching) amplifier, the presented system needs no output filter to reduce the switching frequency harmonics. This filter (usually of multistage type) generally deteriorates the transient response of the system and impairs the feedback loop design. Furthermore, the low-frequency distortions of switching amplifiers caused by the interlock delay of their power transistors are avoided with the presented switched-mode assisted linear amplifier system. This can be considered as a master-slave system with a guiding linear amplifier and a supporting class D slave unit. The paper describes the operating principle of the system, analyzes the fundamental relationships for the circuit design, and presents simulation results. Finally, various further topologies of switched-mode assisted linear amplifiers are given.Index Terms-Class D converters, dc-ac power conversion, power amplifiers, switching amplifiers.

show abstract

Section: Linear Stage Design-output Impedancementioning

confidence: 99%