specified. (Continued)

Specification Definitions

APERTURE JITTER is the variation in aperture delay from

sample to sample. Aperture jitter shows up as input noise.

APERTURE DELAY See Sampling Delay.

DIFFERENTIAL GAIN ERROR is the percentage difference

between the output amplitudes of a given amplitude small

signal, high frequency sine wave input at two different dc in-

put levels.

DIFFERENTIAL PHASE ERROR is the difference in the out-

put phase of a small signal sine wave input at two different

dc input levels.

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 (S/N+D or SINAD). ENOB is defined as (SI-

NAD −1.76) / 6.02.

FULL POWER BANDWIDTH is a measure of the frequency

at which the reconstructed output fundamental drops 3 dB

below its 1MHz value for a full scale input. The test is per-

formed with f

f

tive to the1MHz input signal is the full power bandwidth.

FULL SCALE (FS) INPUT RANGE of the ADC is the input

range of voltages over which the ADC will digitize that input.

For V

(V

FULL SCALE OFFSET ERROR is a measure of how far the

and is defined as V

the voltage at which the transitions from code 1022 to 1023

occurs.

FULL SCALE STEP RESPONSE is defined as the time re-

quired after V

V

and make a conversion with its rated accuracy.

INTEGRAL NON-LINEARITY (INL) is a measure of the de-

viation of each individual code from a line drawn from nega-

The deviation of any given code from this straight line is

measured from the center of that code value.

OUTPUT DELAY is the time delay after the fall of the input

clock before the data update is present at the output pins.

OUTPUT HOLD TIME is the length of time that the output

data is valid after the fall of the input clock.

OVER RANGE RECOVERY TIME is the time required after

V

for the converter to recover and make a conversion with its

rated accuracy.

PIPELINE DELAY (LATENCY) is the number of clock cycles

between initiation of conversion and when that data is pre-

sented to the output driver stage. Data for any given sample

is available by 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.

PSRR (POWER SUPPLY REJECTION RATIO) is the ratio

of the change in dc power supply voltage to the resulting

change in Full Scale Error, expressed in dB.

SAMPLING (APERTURE) DELAY or APERTURE TIME is

that time required after the fall of the clock input for the sam-

pling switch to open. The sample is effectively taken this

amount of time after the fall of the clock input.

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 or dBc, between the RMS values of

the input signal and the peak spurious signal, where a spu-

rious 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, of the rms total of the first six harmonic com-

ponents, to the rms value of the input signal.

ZERO SCALE OFFSET ERROR is the difference between

that just causes a transition from an output code of zero to

an output code of one.

Spectral Response at 20 MSPs

DS100897-35

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