AD7356 datasheet(11/21 Pages) AD

11 / 21 page

AD7356

Data Sheet

Rev. B | Page 10 of 20

TERMINOLOGY

Integral Nonlinearity (INL)

INL is the maximum deviation froma straight line passing

through the endpointsof the ADC transfer function. The

endpoints of the transferfunction are zero scale (1 LSB below

the first code transition)and full scale (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.

Negative Full-Scale Error

Negative full-scale error is the deviation of thefirst code

transition (00 … 000) to (00 … 001) from the ideal (that is,

−VREF + 0.5 LSB)after the midscale error hasbeen adjusted out.

Negative Full-Scale Error Match

Negative full-scale error match is the difference in negative full-

scale error between the two ADCs.

Midscale Error

Midscale error is the deviation of the midscale code transition

(011 … 111) to (100 … 000) from the ideal (that is, 0 V).

Midscale Error Match

Midscale error match is the difference in midscale error

between the two ADCs.

Positive Full-Scale Error

Positive full-scale error is the deviation of the last code

transition (111 … 110) to (111 … 111) from the ideal (that is,

VREF − 1.5 LSB)after the midscale error has been adjustedout.

Positive Full-Scale Error Match

Positive full-scale error match is the differencein positive full-

scale error between the two ADCs.

ADC-to-ADC Isolation

ADC-to-ADC isolation is a measureof the level of crosstalk

between ADC A and ADC B. It is measured byapplying a full-

scale 1 MHzsine wave signal to one of the two ADCs and

applying a full-scale signal of variable frequency to the other

ADC. The ADC-to-ADCisolationis defined as the ratio of the

power of the 1 MHzsignal on the converted ADC to the power

of the noise signal on the other ADC that appears in the FFT.

The noise frequency on the unselectedchannel varies from

100 kHz to 2.5 MHz.

Power Supply RejectionRatio (PSRR)

PSRR is defined as the ratio of the power in the ADC output at

full-scale frequency, f, to the powerof a 100 mV p-p sine wave

applied to the ADC VDD supply of frequency, fS. The frequency

of the input varies from 5 kHzto 25 MHz.

PSRR (dB) = 10 log(Pf/PfS)

where:

Pf is the power at frequency, f, in the ADC output.

PfS is the power at frequency, fS, in the ADC output.

Common-Mode RejectionRatio (CMRR)

CMRR is defined as the ratio of the power in the ADC output

at full-scale frequency, f, to the powerof a 100 mV p-p sine

wave applied to the common-modevoltageof VIN+ and VIN−

of frequency, fS.

CMRR (dB) = 10 log(Pf/PfS)

where:

Pf is the power at frequency (f)in the ADC output.

PfS is the power at frequency (fS)in the ADC output.

Track-and-Hold AcquisitionTime

The track-and-hold amplifierreturns to trackmode at the end

of a conversion. The track-and-hold acquisition time is the time

required for the output of the track-and-hold amplifierto reach

its final value, within ±0.5 LSB, aftertheendofa conversion.

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

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. Noiseis the sum of all nonfundamental signals up

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

dependent on the number of quantizationlevels in the digitiza-

tion process; the morelevels, the smaller thequantization noise.

The theoretical SINAD foran ideal N-bit converter with a sine

wave input is given by

SINAD = (6.02 N + 1.76) dB

Thus, for a 12-bit converter, SINAD is 74 dB and for a 14-bit

converter, SINADis 86 dB.

AD7356 Datasheet(PDF) 11 Page - Analog Devices

AD7356 Datasheet(HTML) 11 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

Datasheet Download

Link URL