Linear Audio USB stick

Now available as a fully searchable PDF collection – the Linear Audio USB stick!

See this page for details and ordering info.

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Linear Audio USB stick

CFB and Transimpedance circuits

 

Ian Hegglun send me two historical articles on the properties of so-called Current Feedback Amplifiers and Transconductance Circuits in general.

Insight into the gain-bandwidth product of amplifiers by Hayatleh, Hart and Lidgey. This is a 2005 article from Electronics World. The other document is from Erik Bruun, Feedback Analysis of Transimpedance Operational Amplifier ciruits, from a 1993 IEEE journal. Please note that these are meant for personal study and education - for professional use you should request copies from the publishers.

One person who is involved in developing and marketing CFA amplifiers send me a pretty complete overview of the CFA opamps out there, including the ones that have been discontinued. You can download the table here. The RED types are the discontinued ones.

A recent addition: Xavier Ramus from TI gave a very nice presentation on the various aspects of CFA versus VFB. As with many (all?) things engineering, some designs shine in a specific design concept, while other shine in another context. It's all 'it depends'.

And even more insights can be gleaned from Chris Pauls articles in AudioExpress, July and August 2018, Current Feedback: Fake News or the Real Deal?. Recommended; with thanks to AX's Editor-in-chief João Martins.