Rainbow Electronics ADC14061 - Manual (Page 11)

Specification Definitions
APERTURE JITTER is the variation in aperture delay from
sample to sample. Aperture jitter shows up as input noise.
APERTURE DELAY is the time from the sampling edge of
the clock to when the input signal is acquired or held for con-
version.
OFFSET ERROR is the difference between the ideal MSB
transition to the actual transition point. The MSB transition
should occur when V
IN
+ = V
IN
−.
DIFFERENTIAL NON-LINEARITY (DNL) is the measure of
the maximum deviation from the ideal step size of 1 LSB.
EFFECTIVE NUMBER OF BITS (ENOB, or EFFECTIVE
BITS) is another method of specifying Signal-to-Noise and
Distortion Ratio, or SINAD. ENOB is defined as (SINAD
−1.76) / 6.02.
FULL SCALE ERROR is the difference between the input
voltage [(V
IN
+) − (V
IN
−)] just causing a transition to positive
full scale and V
REF
− 1.5 LSB, where V
REF
is ( V
REF
+
IN
) −
(V
REF
−
IN
).
FULL POWER BANDWIDTH is a measure of the frequency
at which the reconstructed output fundamental drops 3 dB
below its low frequency value for a full scale input. The test
is performed with f
IN
equal to 100 kHz plus integral multiples
of f
CLK
. The input frequency at which the output is −3 dB
relative to the low frequency input signal is the full power
bandwidth.
INTERMODULATION DISTORTION (IMD) is the creation of
additional spectral components as a result of two sinusoidal
frequencies being applied to the ADC input at the same time.
It is defined as the ratio of the power in the intermodulation
products to the total power in the original frequencies. IMD is
usually expressed in dB.
INTEGRAL NON-LINEARITY (INL) is a measure of the de-
viation of each individual code from a line drawn from nega-
tive full scale (
1 ⁄ 2 LSB below the first code transition) through
positive full scale (the last code transition). The deviation of
any given code from this straight line is measured from the
center of that code value.
PIPELINE DELAY (LATENCY) is the number of clock cycles
between initiation of conversion and the availability of that
same conversion result at the output. New data is available
at every clock cycle, but the data lags the conversion by the
pipeline delay.
SIGNAL TO NOISE RATIO (SNR) is the ratio, expressed in
dB, of the rms value of the input signal to the rms value of the
sum of all other spectral components below one-half the
sampling frequency, not including harmonics or dc.
SIGNAL TO NOISE PLUS DISTORTION (S/(N+D) or SI-
NAD)) Is the ratio, expressed in dB, of the rms value of the
input signal to the rms value of all of the other spectral com-
ponents below half the clock frequency, including harmonics
but excluding dc.
SPURIOUS FREE DYNAMIC RANGE (SFDR) is the differ-
ence, expressed in dB, between the rms values of the input
signal and the peak spurious signal, where a spurious signal
is any signal present in the output spectrum that is not
present at the input.
TOTAL HARMONIC DISTORTION (THD) is the ratio, ex-
pressed in dB or dBc, of the rms total of the first nine har-
monic components, to the rms value of the input signal.
Timing Diagrams
DS100103-15
TIMING DIAGRAM 1. Output Timing
www.national.com 11