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1) What is it ?
The EOSC10KV3 is an ultra low THD sine wave oscillator, used as a reference for audio testing
purpose or evaluating high resolution/high performance ADC.
This design come from the AN67 Linear-Technology Application Note from Dale Eagar.
The full explanation of the oscillator is described in this app note, please refer to it for more
informations.
Some little improvements has been done to became the design note as a real PCB design.
As claimed by the original author, the THD level reached by the oscillator surpass all
measurements
equipments available from now. THD measurement is only possible using techniques to remove
fundamental and then amplifying THD products for further FFT measurements.
So, the THD level has been measured with my own set-up* to be less than -136 dBc (H2).
All others harmonics are much below and flooded in the noise floor (Vout= 0 dBV = 1Vrms).
Extended measurements made using Audio Precision SYS2722 (thanks to Samuel Groner) has confirmed
these THD levels. (see chapter 5 for details).
( * : My measurement sertup is made with 10kHz passive notch filter with 40dB post gain, EADCAKMv1
AK5394A based ADC (from me) with 192kHz S/PDIF output and ESI juli@ PCI soundcard with 192kHz
SPDIF input).
EOSC10KV3 views
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