Datasheet

(AINP+AINN)
2
ADS1601
SBAS322D –DECEMBER 2004–REVISED OCTOBER 2011 www.ti.com
DEFINITIONS
Absolute Input Voltage Intermodulation Distortion (IMD)
Absolute input voltage, given in volts, is the voltage of IMD, given in dB, is measured while applying two
each analog input (AINN or AINP) with respect to input signals of the same magnitude, but with slightly
AGND. different frequencies. It is calculated as the difference
between the rms amplitude of the input signal to the
rms amplitude of the peak spurious signal.
Aperture Delay
Aperture delay is the delay between the rising edge
Offset Error
of CLK and the sampling of the input signal.
Offset Error, given in % of FSR, is the output reading
when the differential input is zero.
Common-Mode Input Voltage
Common-mode input voltage (V
CM
) is the average
Offset Error Drift
voltage of the analog inputs:
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
Differential Input Voltage
temperatures.
Differential input voltage (V
IN
) is the voltage
Signal-to-Noise Ratio (SNR)
difference between the analog inputs (AINP−AINN).
SNR, given in dB, is the ratio of the rms value of the
Differential Nonlinearity (DNL)
input signal to the sum of all the frequency
components below f
CLK
/2 (the Nyquist frequency)
DNL, given in least-significant bits of the output code
excluding the first six harmonics of the input signal
(LSB), is the maximum deviation of the output code
and the dc component.
step sizes from the ideal value of 1LSB.
Signal-to-Noise and Distortion (SINAD)
Full-Scale Range (FSR)
SINAD, given in dB, is the ratio of the rms value of
FSR is the difference between the maximum and
the input signal to the sum of all the frequency
minimum measurable input signals (FSR = 1.88V
REF
).
components below fCLK/2 (the Nyquist frequency)
including the harmonics of the input signal but
Gain Error
excluding the dc component.
Gain error, given in %, is the error of the full-scale
input signal with respect to the ideal value.
Spurious-Free Dynamic Range (SFDR)
SFDR, given in dB, is the difference between the rms
Gain Error Drift
amplitude of the input signal to the rms amplitude of
Gain error drift, given in ppm/°C, is the drift over
the peak spurious signal.
temperature of the gain error. The gain error is
specified as the larger of the drift from ambient
Total Harmonic Distortion (THD)
(T = 25°C) to the minimum or maximum operating
THD, given in dB, is the ratio of the sum of the rms
temperatures.
value of the first six harmonics of the input signal to
the rms value of the input signal.
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.
6 Copyright © 2004–2011, Texas Instruments Incorporated