Low-noise oscillator circuit having negative feedback
AssigneeSennheiser electronic GmbH & Co. KG
InventorFrank Hagemeyer
Life of this patent
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Abstract
A low-noise oscillator circuit with an amplifier element for negative feedback, specifically a transistor. In addition to a positive feedback of the oscillator transistor, provision is made for a negative-feedback loop with a pass band of 0 (thus DC coupling) to 1/4 to 1/100 of the oscillation frequency of the oscillator, in order to regulate out fluctuations of the current of the amplifier element.
Claims9
Low-noise oscillator circuit with an amplifier element connected for feedback, to which amplifier element a resonator, e.g. a resonant circuit, is coupled, in which oscillator circuit, in addition to a positive feedback of the amplifier for the oscillation generation, a negative feedback loop between the output and the input of the amplifier element is provided for, characterized hereby, that the pass band of the negative-feedback loop (R5, C7, Q2, R1;
- L13, C17, Q12, C20, R11) is set at a pass band from 0 (DC) to 1/4-1/100 of the oscillator frequency by means of a low-pass filter (L2/R6, R5/C7, R1/C4/C5 . . . ;
- L13/C17, C20/R11/C14/C15 . . . ).
Dependencies are inferred from the claim text.