Electronic Components Datasheet Search 

AD7321 Datasheet(PDF) 14 Page  Analog Devices 

AD7321 Datasheet(HTML) 14 Page  Analog Devices 
14 / 36 page AD7321 Rev. 0  Page 14 of 36 TERMINOLOGY Differential Nonlinearity Negative FullScale Error This is the difference between the measured and the ideal 1 LSB change between any two adjacent codes in the ADC. This applies when using twos complement output coding and any of the bipolar analog input ranges. This is the deviation of the first code transition (10 ... 000) to (10 ... 001) from the ideal (that is, −4 × VREF + 1 LSB, −2 × VREF + 1 LSB, −VREF + 1 LSB) after adjusting for the bipolar zero code error. Integral Nonlinearity This is the maximum deviation from a straight line passing through the endpoints of the ADC transfer function. The endpoints of the transfer function are zero scale (a point 1 LSB below the first code transition) and full scale (a point 1 LSB above the last code transition). Negative FullScale Error Match This is the difference in negative fullscale error between any two input channels. TrackandHold Acquisition Time Offset Code Error The trackandhold amplifier returns into track mode after the 14th SCLK rising edge. Trackandhold acquisition time is the time required for the output of the trackandhold amplifier to reach its final value, within ±½ LSB, after the end of a conversion. For the ±2.5 V range, the specified acquisition time is the time required for the trackandhold amplifier to settle to within ±1 LSB. This applies to straight binary output coding. It is the deviation of the first code transition (00 ... 000) to (00 ... 001) from the ideal, that is, AGND + 1 LSB. Offset Error Match This is the difference in offset error between any two input channels. Gain Error Signal to (Noise + Distortion) Ratio This applies to straight binary output coding. It is the deviation of the last code transition (111 ... 110) to (111 ... 111) from the ideal (that is, 4 × VREF − 1 LSB, 2 × VREF − 1 LSB, VREF −1 LSB) after adjusting for the offset error. This is the measured ratio of signal to (noise + distortion) at the output of the A/D converter. The signal is the rms amplitude of the fundamental. Noise is the sum of all nonfundamental signals up to half the sampling frequency (fS/2), excluding dc. The ratio is dependent on the number of quantization levels in the digi tization process. The more levels, the smaller the quantization noise. Theoretically, the signal to (noise + distortion) ratio for an ideal Nbit converter with a sine wave input is given by Gain Error Match This is the difference in gain error between any two input channels. Bipolar Zero Code Error Signal to (Noise + Distortion) = (6.02 N + 1.76) dB This applies when using twos complement output coding and a bipolar analog input. It is the deviation of the midscale transition (all 1s to all 0s) from the ideal input voltage, that is, AGND − 1 LSB. For a 13bit converter, this is 80.02 dB. Total Harmonic Distortion Total harmonic distortion (THD) is the ratio of the rms sum of harmonics to the fundamental. For the AD7321 it is defined as Bipolar Zero Code Error Match This refers to the difference in bipolar zero code error between any two input channels. 1 2 6 2 5 2 4 2 3 2 2 log 20 ) dB ( V V V V V V THD + + + + = Positive FullScale Error where V1 is the rms amplitude of the fundamental, and V2, V3, V4, V5, and V6 are the rms amplitudes of the second through the sixth harmonics. This applies when using twos complement output coding and any of the bipolar analog input ranges. It is the deviation of the last code transition (011 ... 110) to (011 ... 111) from the ideal (4 × VREF − 1 LSB, 2 × VREF − 1 LSB, VREF − 1 LSB) after adjusting for the bipolar zero code error. Peak Harmonic or Spurious Noise Peak harmonic or spurious noise is defined as the ratio of the rms value of the next largest component in the ADC output spectrum (up to fS/2, excluding dc) to the rms value of the fundamental. Normally, the value of this specification is determined by the largest harmonic in the spectrum, but for ADCs where the harmonics are buried in the noise floor, the largest harmonic could be a noise peak. Positive FullScale Error Match This is the difference in positive fullscale error between any two input channels. 
Link URL 
Privacy Policy 
ALLDATASHEET.COM 
Does ALLDATASHEET help your business so far? [ DONATE ] 
About Alldatasheet  Advertisement  Datasheet Upload  Contact us  Privacy Policy  Alldatasheet API  Link Exchange  Manufacturer List All Rights Reserved© Alldatasheet.com 
Russian : Alldatasheetru.com  Korean : Alldatasheet.co.kr  Spanish : Alldatasheet.es  French : Alldatasheet.fr  Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com  Polish : Alldatasheet.pl  Vietnamese : Alldatasheet.vn 