Electronic Components Datasheet Search 

AD7674 Datasheet(PDF) 8 Page  Analog Devices 

AD7674 Datasheet(HTML) 8 Page  Analog Devices 
8 / 24 page REV. B AD7663 –8– DEFINITION OF SPECIFICATIONS Integral Nonlinearity Error (INL) Linearity error refers to the deviation of each individual code from a line drawn from “negative full scale” through “positive full scale.” The point used as negative full scale occurs 1/2 LSB before the first code transition. Positive full scale is defined as a level 1 1/2 LSB beyond the last code transition. The deviation is measured from the middle of each code to the true straight line. Differential Nonlinearity Error (DNL) In an ideal ADC, code transitions are 1 LSB apart. Differential nonlinearity is the maximum deviation from this ideal value. It is often specified in terms of resolution for which no missing codes are guaranteed. FullScale Error The last transition (from 011 . . . 10 to 011 ... 11 in twos complement coding) should occur for an analog voltage 1 1/2 LSB below the nominal full scale (2.499886 V for the ±2.5 V range). The fullscale error is the deviation of the actual level of the last transition from the ideal level. Bipolar Zero Error The difference between the ideal midscale input voltage (0 V) and the actual voltage producing the midscale output code. Unipolar Zero Error In Unipolar Mode, the first transition should occur at a level 1/2 LSB above analog ground. The unipolar zero error is the deviation of the actual transition from that point. SpuriousFree Dynamic Range (SFDR) The difference, in decibels (dB), between the rms amplitude of the input signal and the peak spurious signal. Effective Number of Bits (ENOB) A measurement of the resolution with a sine wave input. It is related to S/(N+D) by the following formula: ENOB S N D dB =+ []  ) () 176 602 .. and is expressed in bits. Total Harmonic Distortion (THD) The ratio of the rms sum of the first five harmonic components to the rms value of a fullscale input signal, expressed in decibels. SignaltoNoise Ratio (SNR) The ratio of the rms value of the actual input signal to the rms sum of all other spectral components below the Nyquist fre quency, excluding harmonics and dc. The value for SNR is expressed in decibels. Signalto(Noise + Distortion) Ratio (S/[N+D]) The ratio of the rms value of the actual input signal to the rms sum of all other spectral components below the Nyquist frequency, including harmonics but excluding dc. The value for S/(N+D) is expressed in decibels. Aperture Delay A measure of the acquisition performance measured from the falling edge of the CNVST input to when the input signal is held for a conversion. Transient Response The time required for the AD7663 to achieve its rated accuracy after a fullscale step function is applied to its input. 
