Datasheet AD9203 (Analog Devices) - 8

AD9203 TERMINOLOGY Integral Nonlinearity Error (INL) Signal-To-Noise Ratio (SNR)
Linearity error refers to the deviation of each individual code SNR is the ratio of the rms value of the measured input signal to from a line drawn from negative full scale through positive full the rms sum of all other spectral components below the Nyquist scale. The point used as negative full scale occurs 1/2 LSB frequency, excluding harmonics and dc. The value for SNR is before the first code transition. Positive full scale is defined as a expressed in decibels. level 1 1/2 LSB beyond the last code transition. The deviation is measured from the middle of each particular code to the true
Spurious-Free Dynamic Range (SFDR)
straight line. The difference in dB between the rms amplitude of the input signal and the peak spurious signal.
Differential Nonlinearity Error (DNL, No Missing Codes)
An ideal ADC exhibits code transitions that are exactly 1 LSB
Offset Error
apart. DNL is the deviation from this ideal value. Guaranteed First transition should occur for an analog value 1/2 LSB above no missing codes to 10-bit resolution indicates that all 1024 negative full scale. Offset error is defined as the deviation of the codes respectively, must be present over all operating ranges. actual transition from that point.
Signal-To-Noise and Distortion (S/N+D, SINAD) Ratio Gain Error
S/N+D is the ratio of the rms value of the measured input signal The first code transition should occur at an analog value 1/2 to the rms sum of all other spectral components below the LSB above negative full scale. The last transition should occur Nyquist frequency, including harmonics but excluding dc. The for an analog value 1 1/2 LSB below the positive full scale. Gain value for S/N+D is expressed in decibels. error is the deviation of the actual difference between first and last code transitions and the ideal difference between first and
Effective Number of Bits (ENOB)
last code transitions. For a sine wave, SINAD can be expressed in terms of the number of bits. Using the following formula,
Power Supply Rejection
The specification shows the maximum change in full scale from N = (SINAD – 1.76)/6.02 the value with the supply at the minimum limit to the value with the supply at its maximum limit. it is possible to get a measure of performance expressed as N, the effective number of bits.
Aperture Jitter
Aperture jitter is the variation in aperture delay for successive Thus, effective number of bits for a device for sine wave inputs samples and is manifested as noise on the input to the A/D. at a given input frequency can be calculated directly from its measured SINAD.
Aperture Delay
Aperture delay is a measure of the sample-and-hold amplifier
Total Harmonic Distortion (THD)
(SHA) performance and is measured from the rising edge of the THD is the ratio of the rms sum of the first six harmonic clock input to when the input signal is held for conversion. components to the rms value of the measured input signal and is expressed as a percentage or in decibels.
Pipeline Delay (Latency)
The number of clock cycles between conversion initiation and the associated output data being made available. New output data is provided on every rising edge. Rev. B | Page 7 of 28 Document Outline FEATURES GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM PRODUCT HIGHLIGHTS SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL CHARACTERISTICS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TERMINOLOGY TYPICAL PERFORMANCE CHARACTERISTICS OPERATIONS THEORY OF OPERATION OPERATIONAL MODES INPUT AND REFERENCE OVERVIEW INTERNAL REFERENCE CONNECTION EXTERNAL REFERENCE OPERATION CLAMP OPERATION DRIVING THE ANALOG INPUT OP AMP SELECTION GUIDE DIFFERENTIAL MODE OF OPERATION POWER CONTROL INTERFACING TO 5 V SYSTEMS CLOCK INPUT AND CONSIDERATIONS DIGITAL INPUTS AND OUTPUTS APPLICATIONS DIRECT IF DOWN CONVERSION ULTRASOUND APPLICATIONS EVALUATION BOARD OUTLINE DIMENSIONS ORDERING GUIDE