Datasheet

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SBAS274H − MARCH 2003 − REVISED MAY 2007
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6
DEFINITIONS
Absolute Input Voltage
Absolute input voltage, given in volts, is the voltage of
each analog input (AINN or AINP) with respect to
AGND.
Aperture Delay
Aperture delay is the delay between the rising edge of
CLK and the sampling of the input signal.
Common-Mode Input Voltage
Common-mode input voltage (V
CM
) is the average volt-
age of the analog inputs:
(AINP ) AINN)
2
Differential Input Voltage
Differential input voltage (V
IN
) is the voltage difference
between the analog inputs: (AINP−AINN).
Differential Nonlinearity (DNL)
DNL, given in least-significant bits of the output code
(LSB), is the maximum deviation of the output code step
sizes from the ideal value of 1LSB.
Full-Scale Range (FSR)
FSR is the difference between the maximum and mini-
mum measurable input signals. FSR = 2 × 1.467V
REF
.
Gain Error
Gain error, given in %, is the error of the full-scale input
signal with respect to the ideal value.
Gain Error Drift
Gain error drift, given in ppm/_C, is the drift over tem-
perature of the gain error. The gain error is specified as
the larger of the drift from ambient (T = 25_C) to the
minimum or maximum operating temperatures.
Integral Nonlinearity (INL)
INL, given in least-significant bits of the output code
(LSB), is the maximum deviation of the output codes
from a best fit line.
Intermodulation Distortion (IMD)
IMD, given in dB, is measured while applying two input
signals of the same magnitude, but with slightly different
frequencies. It is calculated as the difference between
the rms amplitude of the input signal to the rms ampli-
tude of the peak spurious signal.
Offset Error
Offset Error, given in % of FSR, is the output reading
when the differential input is zero.
Offset Error Drift
Offset error drift, given in ppm of FSR/_C, is the drift
over temperature of the offset error. The offset error is
specified as the larger of the drift from ambient (T =
25_C) to the minimum or maximum operating tempera-
tures.
Signal-to-Noise Ratio (SNR)
SNR, given in dB, is the ratio of the rms value of the in-
put signal to the sum of all the frequency components
below f
CLK
/2 (the Nyquist frequency) excluding the first
six harmonics of the input signal and the dc component.
Signal-to-Noise and Distortion (SINAD)
SINAD, given in dB, is the ratio of the rms value of the
input signal to the sum of all the frequency components
below f
CLK
/2 (the Nyquist frequency) including the har-
monics of the input signal but excluding the dc compo-
nent.
Spurious-Free Dynamic Range (SFDR)
SFDR, given in dB, is the difference between the rms
amplitude of the input signal to the rms amplitude of the
peak spurious signal.
Total Harmonic Distortion (THD)
THD, given in dB, is the ratio of the sum of the rms value
of the first six harmonics of the input signal to the rms
value of the input signal.