AD5592R datasheet(21/54 Pages) AD

21 / 54 page

Data Sheet

AD5592R

TERMINOLOGY

analog.com

Rev. G | 21 of 54

ADC TERMINOLOGY

Integral Nonlinearity (INL)

INL is the maximum deviation from a straight line passing through

the endpoints of the ADC transfer function. The end-points of the

transfer function are zero scale, a point that is 1 LSB below the first

code transition, and full scale, a point that is 1 LSB above the last

code transition.

Differential Nonlinearity (DNL)

DNL is the difference between the measured and the ideal 1 LSB

change between any two adjacent codes in the ADC.

Offset Error

Offset error is the deviation of the first code transition (00 … 000) to

(00 … 001) from the ideal, that is, AGND + 1 LSB.

Offset Error Match

Offset error match is the difference in offset error between any two

channels.

Gain Error

Gain error is the deviation of the last code transition (111 … 110) to

(111 … 111) from the ideal (that is, VREF − 1 LSB) after the offset

error has been adjusted out.

Channel-to-Channel Isolation

Channel-to-channel isolation is a measure of the level of crosstalk

between channels. It is measured by applying a full-scale, 5 kHz

sine wave signal to all non-selected ADC input channels and deter-

mining how much that signal is attenuated in the selected channel.

This specification is the worst case across all ADC channels for the

AD5592R/AD5592R-1.

Track-and-Hold Acquisition Time

The track-and-hold amplifier enters hold mode on the falling edge of

SYNC and returns to track mode when the conversion is complete.

The track-and-hold acquisition time is the minimum time required

for the track-and-hold amplifier to remain in track mode for its

output to reach and settle to within ±1 LSB of the applied input

signal, given a step change to the input signal.

Signal-to-Noise-and-Distortion (SINAD) Ratio

SINAD 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 sum of all non-fundamental signals up

to half the sampling frequency (fS/2), excluding dc. The ratio is

dependent on the number of quantization levels in the digitization

process; the more levels, the smaller the quantization noise. The

theoretical SINAD ratio for an ideal N-bit converter with a sine wave

input is given by

SINAD (dB) = 6.02N + 1.76

(1)

Thus, for a 12-bit converter, SINAD is 74 dB.

Total Harmonic Distortion (THD)

THD is the ratio of the rms sum of harmonics to the fundamental.

For the AD5592R/AD5592R-1, it is defined as

THD dB =20×log V22+V32+V42+V52+V62

(2)

where:

V1 is the rms amplitude of the fundamental.

V2, V3, V4, V5, and V6 are the rms amplitudes of the second through

the sixth harmonics.

Peak Harmonic or Spurious Noise (SFDR)

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 and 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, it is a noise peak.

DAC TERMINOLOGY

Relative Accuracy or Integral Nonlinearity (INL)

For the DAC, relative accuracy or integral nonlinearity is a meas-

urement of the maximum deviation, in LSBs, from a straight line

passing through the endpoints of the DAC transfer function. A

typical INL vs. code plot is shown in Figure 18.

Differential Nonlinearity (DNL)

Differential nonlinearity is the difference between the measured

change and the ideal 1 LSB change between any two adjacent

codes. A specified differential nonlinearity of ±1 LSB maximum en-

sures monotonicity. This DAC is guaranteed monotonic by design.

A typical DNL vs. code plot can be seen in Figure 19.

Zero Code Error

Zero code error is a measurement of the output error when zero

code (0x000) is loaded to the DAC register. Ideally, the output

is 0 V. The zero code error is always positive in the AD5592R/

AD5592R-1 because the output of the DAC cannot go below 0 V

due to a combination of the offset errors in the DAC and the output

amplifier. Zero code error is expressed in mV.

Gain Error

Gain error is a measure of the span error of the DAC. It is the

deviation in slope of the DAC transfer characteristic from the ideal

expressed as % FSR.

Offset Error Drift

Offset error drift is a measurement of the change in offset error with

a change in temperature. It is expressed in µV/°C.

AD5592R Datasheet(PDF) 21 Page - Analog Devices

AD5592R Datasheet(HTML) 21 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

Datasheet Download

Link URL