Barkhausen stability criterion

For the noise in the output of a ferromagnet upon a change in the magnetizing force, see Barkhausen effect.

Block diagram of a feedback oscillator circuit to which the Barkhausen criterion applies. It consists of an amplifying element A whose output vo is fed back into its input vf through a feedback network β(jω).
To find the loop gain, the feedback loop is considered broken at some point and the output vo for a given input vi is calculated:

In electronics, the Barkhausen stability criterion is a mathematical condition to determine when a linear electronic circuit will oscillate.[1][2][3] It was put forth in 1921 by German physicist Heinrich Barkhausen (1881–1956).[4] It is widely used in the design of electronic oscillators, and also in the design of general negative feedback circuits such as op amps, to prevent them from oscillating.

  1. ^ Basu, Dipak (2000). Dictionary of Pure and Applied Physics. CRC Press. pp. 34–35. ISBN 1420050222.
  2. ^ Rhea, Randall W. (2010). Discrete Oscillator Design: Linear, Nonlinear, Transient, and Noise Domains. Artech House. p. 3. ISBN 978-1608070480.
  3. ^ Carter, Bruce; Ron Mancini (2009). Op Amps for Everyone, 3rd Ed. Newnes. pp. 342–343. ISBN 978-0080949482.
  4. ^ Barkhausen, H. (1935). Lehrbuch der Elektronen-Röhren und ihrer technischen Anwendungen [Textbook of Electron Tubes and their Technical Applications] (in German). Vol. 3. Leipzig: S. Hirzel. ASIN B0019TQ4AQ. OCLC 682467377.