| 摘要 |
The present invention relates to a crystal oscillator for generating an oscillator signal having a predetermined frequency, wherein a frequency-dependent negative resistance circuit (FDNR) having a negative resistance inversely proportional to frequency squared is connected to an oscillator crystal (Q). Thereby, the voltage across the crystal (Q) approaches the time integral of a current supplied by an amplitude control means ( 10 ) and the input voltage of the amplitude control means ( 10 ) approaches the time integral of the current flowing through the crystal (Q). Due to this integration behavior of the frequency-dependent negative resistance circuit (FDNR), no accurate capacitors or other accurate reactive components are necessary. High accuracy can thus be achieved without trimming As an example, the frequency-dependent negative resistance circuit may comprise a first integrator circuit having an output connected to the oscillator crystal (Q), a second integrator circuit having an input connected to the crystal (Q), and an amplifier circuit used for controlling the amplitude.
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