Datasheet

AD5932 Data Sheet
Rev. A | Page 14 of 28
TERMINOLOGY
Integral Nonlinearity (INL)
Integral nonlinearity is the maximum deviation of any code
from a straight line passing through the endpoints of the
transfer function. The endpoints of the transfer function are
zero scale and full scale. The error is expressed in LSBs.
Differential Nonlinearity (DNL)
Differential nonlinearity is the difference between the measured
and ideal 1 LSB change between two adjacent codes in the DAC.
A specified differential nonlinearity of ±1 LSB maximum
ensures monotonicity.
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 SFDR refers to the
largest spur or harmonic that is 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 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.
Total Harmonic Distortion (THD)
Total harmonic distortion is the ratio of the rms sum of
harmonics to the rms value of the fundamental. For the
AD5932, THD is defined as:
1
6
54
32
V
VVVVV
THD
22222
log20)dB(
++++
=
where:
V
1
is the rms amplitude of the fundamental.
V
2
, V
3
, V
4
, V
5
, and V
6
are the rms amplitudes of the second
through the sixth harmonic.
Signal-to-Noise Ratio (SNR)
The signal-to-noise ratio 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 dB.
Clock Feedthrough
There is feedthrough from the MCLK input to the analog
output. Clock feedthrough refers to the magnitude of the
MCLK signal relative to the fundamental frequency in the
AD5932 output spectrum.