AD5934
Rev. A | Page 11 of 40
TEMINOLOGY
Total System Accuracy
The AD5934 can accurately measure a range of impedance
values to less than 0.5% of the correct impedance value for
supply voltages between 2.7 V to 5.5 V.
Spurious-Free Dynamic Range (SFDR)
Along with the frequency of interest, harmonics of the fundamental
frequency and images of these frequencies are present at the
output of a DDS device. The spurious-free dynamic range refers
to the largest spur or harmonic present in the band of interest.
The wideband SFDR gives the magnitude of the largest harmonic
or spur relative to the magnitude of the fundamental frequency
in the 0 Hz to Nyquist bandwidth. The narrow-band SFDR
gives the attenuation of the largest spur or harmonic in a
bandwidth of ±200 kHz, about the fundamental frequency.
Signal-to-Noise Ratio (SNR)
SNR is the ratio of the rms value of the measured output signal
to the rms sum of all other spectral components below the
Nyquist frequency. The value for SNR is expressed in decibels.
Total Harmonic Distortion (THD)
THD is the ratio of the rms sum of harmonics to the fundamental,
where V1 is the rms amplitude of the fundamental, and V2, V3,
V4, V5, and V6 are the rms amplitudes of the second through the
sixth harmonics. THD is defined as
V1
V6
V5
V4
V3
V2
THD
2
2
2
2
2
log
20
)
dB
(
+
+
+
+
=
Содержание AD5934
Страница 35: ...AD5934 Rev A Page 35 of 40 SCHEMATICS 05325 144 Figure 40 EVAL AD5934EBZ USB Schematic ...
Страница 36: ...AD5934 Rev A Page 36 of 40 05325 145 Figure 41 EVAL AD5934EBZ Schematic ...
Страница 37: ...AD5934 Rev A Page 37 of 40 05325 146 Figure 42 Linear Regulator on EVAL AD5934EBZ ...
Страница 38: ...AD5934 Rev A Page 38 of 40 05325 147 Figure 43 Decoupling on the EVAL AD5934EBZ ...