TSA1002_04 Datasheet, PDF (8/20 Pages) STMicroelectronics – 10-BIT, 50MSPS, 50mW A/D CONVERTER

TSA1002
DEFINITIONS OF SPECIFIED PARAMETERS
Signal to Noise Ratio (SNR)
STATIC PARAMETERS
Static measurements are performed through
method of histograms on a 2MHz input signal,
sampled at 40Msps, which is high enough to fully
characterize the test frequency response. The
input level is +1dBFS to saturate the signal.
Differential Non Linearity (DNL)
The ratio of the rms value of the fundamental
component to the rms sum of all other spectral
N _{components in the Nyquist band (fs/2) excluding}
DC, fundamental and the first five harmonics.
SNR is reported in dB.
I ^G _{Signal to Noise and Distortion Ratio (SINAD)}
S ^{Similar ratio as for SNR but including the harmonic}
distortion components in the noise figure (not DC
E ^{signal). It is expressed in dB.}
The average deviation of any output code width
from the ideal code width of 1 LSB.
D ^{From the SINAD, the Effective Number of Bits}
(ENOB) can easily be deduced using the formula:
SINAD= 6.02 × ENOB + 1.76 dB.
Integral Non linearity (INL)
An ideal converter presents a transfer function as
W being the straight line from the starting code to the
ending code. The INL is the deviation for each
E ^{) transition from this ideal curve.}
N ^{ct(s DYNAMIC PARAMETERS}
du Dynamic measurements are performed by
R ^{ro spectral analysis, applied to an input sine wave of}
various frequencies and sampled at 40Msps.
O ^{te P The input level is -1dBFS to measure the linear}
behavior of the converter. All the parameters are
le given without correction for the full scale ampli-
F ^{o tude performance except the calculated ENOB}
s _parameter.
T ^{Ob Spurious Free Dynamic Range (SFDR)}
) ^{- The ratio between the power of the worst spurious}
O _t(s ^{signal (not always an harmonic) and the amplitude}
of fundamental tone (signal power) over the full
c _{Nyquist band. It is expressed in dBc.}
N _{rodu Total Harmonic Distortion (THD)}
P _{The ratio of the rms sum of the first five harmonic}
te ^{distortion components to the rms value of the}
Obsole ^{fundamental line. It is expressed in dB.}
When the applied signal is not Full Scale (FS), but
has an A₀ amplitude, the SINAD expression
becomes:
SINAD_2Ao=SINAD_{Full Scale}+ 20 log (2A₀/FS)
SINAD_2Ao=6.02 × ENOB + 1.76 dB + 20 log (2A₀/
FS)
The ENOB is expressed in bits.
Analog Input Bandwidth
The maximum analog input frequency at which the
spectral response of a full power signal is reduced
by 3dB. Higher values can be achieved with
smaller input levels.
Effective Resolution Bandwidth (ERB)
The band of input signal frequencies that the ADC
is intended to convert without loosing linearity i.e.
the maximum analog input frequency at which the
SINAD is decreased by 3dB or the ENOB by 1/2
bit.
Pipeline delay
Delay between the initial sample of the analog
input and the availability of the corresponding
digital data output, on the output bus. Also called
data latency. It is expressed as a number of clock
cycles.
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