ADC1175CIMTC National Semiconductor, ADC1175CIMTC Datasheet - Page 10

• Manufacturer Part Number: ADC1175CIMTC
• Description: 8-Bit/ 20MHz/ 60mW A/D Converter
• Manufacturer: National Semiconductor

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Specification Definitions
ANALOG INPUT BANDWIDTH is a measure of the frequen-
cy 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
f
to the low frequency input signal is the full power bandwidth.
APERTURE JITTER is the time uncertainty of the sampling
point (t
BOTTOM OFFSET is the difference between the input volt-
age that just causes the output code to transition to the first
code and the negative reference voltage. Bottom offset is de-
fined as E
input voltage. Note that this is different from the normal Zero
Scale Error.
DIFFERENTIAL GAIN ERROR is the percentage difference
between the output amplitudes of a high frequency recon-
structed sine wave at two different d.c. levels.
DIFFERENTIAL NON-LINEARITY (DNL) is the measure of
the maximum deviation from the ideal step size of 1 LSB.
DIFFERENTIAL PHASE ERROR is the difference in the out-
put phase of a reconstructed small signal sine wave at two
different d.c. levels.
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 and says that the converter is equivalent to a
perfect ADC of this (ENOB) number of bits.
INTEGRAL NON-LINEARITY (INL) is a measure of the de-
viation of each individual code from a line drawn from zero
scale (½LSB below the first code transition) through positive
full scale (½LSB above the last code transition). The deviation
of any given code from this straight line is measured from the
center of that code value. The end point test method is used.
OUTPUT DELAY is the time delay after the rising edge of the
input clock before the data update is present at the output
pins.
CLK
. The input frequency at which the output is −3 dB relative
DS
), or the range of variation in the sampling delay.
OB
= V
Differential Phase vs. Temperature
ZT
IN
equal to 100 kHz plus integer multiples of
- V
RB
, where V
ZT
is the first code transition
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OUTPUT HOLD TIME is the length of time that the output data
is valid after the rise of the input clock.
PIPELINE DELAY (LATENCY) is the number of clock cycles
between initiation of conversion and when that data is pre-
sented to the output stage. Data for any give sample is
available the Pipeline Delay plus the Output Delay after that
sample is taken. New data is available at every clock cycle,
but the data lags the conversion by the pipeline delay.
SAMPLING (APERTURE) DELAY is that time required after
the fall of the clock input for the sampling switch to open. The
Sample/Hold circuit effectively stops capturing the input sig-
nal and goes into the "hold" mode t
SIGNAL TO NOISE RATIO (SNR) is the ratio of the rms value
of the input signal to the rms value of the other spectral com-
ponents below one-half the sampling frequency, not including
harmonics or d.c.
SIGNAL TO NOISE PLUS DISTORTION (S/(N+D) or
SINAD) is the ratio of the rms value of the input signal to the
rms value of all of the other spectral components below half
the clock frequency, including harmonics but excluding d.c.
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.
TOP OFFSET is the difference between the positive refer-
ence voltage and the input voltage that just causes the output
code to transition to full scale and is defined as E
V
that this is different from the normal Full Scale Error.
TOTAL HARMONIC DISTORTION (THD) is the ratio of the
rms total of the first six harmonic components, to the rms val-
ue of the input signal.
RT
. Where V
Spectral Response at f
FT
is the full scale transition input voltage. Note
CLK
DS
= 20 MSPS
after the clock goes low.
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OT
= V
FT
−