Datasheet

Table Of Contents
Data Sheet ADuC832
Rev. B | Page 29 of 92
TERMINOLOGY
ADC SPECIFICATIONS
Integral Nonlinearity
This is the maximum deviation of any code from a straight line
passing through the endpoints of the ADC transfer function.
The endpoints of the transfer function are zero scale, a point
½ LSB below the first code transition, and full scale, a point
½ LSB above the last code transition.
Differential Nonlinearity
This is the difference between the measured and the ideal 1 LSB
change between any two adjacent codes in the ADC.
Offset Error
This is the deviation of the first code transition (0000 000) to
(0000 001) from the ideal, that is, +½ LSB.
Gain Error
This is the deviation of the last code transition from the ideal
analog input voltage (full scale 1.5 LSB) after the offset error
has been adjusted out.
Signal-to-Noise and Distortion (SINAD) Ratio
This is the measured ratio of signal-to-noise and distortion at
the output of the ADC. The signal is the rms amplitude of the
fundamental. Noise is the rms sum of all nonfundamental
signals up to half the sampling frequency (f
S
/2), excluding dc.
The ratio is dependent upon the number of quantization levels
in the digitization process; the more levels there are, the smaller
the quantization noise. The theoretical signal to (noise +
distortion) ratio for an ideal N-bit converter with a sine wave
input is given by:
Signal-to-Noise and Distortion = (6.02N + 1.76) dB
Thus for a 12-bit converter, this is 74 dB.
Total Harmonic Distortion
Tot al harmonic distortion is the ratio of the rms sum of the
harmonics to the fundamental.
DAC SPECIFICATIONS
Relative Accuracy
Relative accuracy or endpoint linearity is a measure of the
maximum deviation from a straight line passing through the
endpoints of the DAC transfer function. It is measured after
adjusting for zero error and full-scale error.
Voltage Output Settling Time
This is the amount of time it takes for the output to settle to a
specified level for a full-scale input change.
Digital-to-Analog Glitch Energy
This is the amount of charge injected into the analog output
when the inputs change state. It is specified as the area of the
glitch in nV sec.