AD6644STSLASHPCBZ datasheet(14/25 Pages) AD

14 / 25 page

AD6644

Rev. D | Page 13 of 24

TERMINOLOGY

Analog Bandwidth

The analog input frequency at which the spectral power of the

fundamental frequency (as determined by the FFT analysis) is

reduced by 3 dB.

Aperture Delay

The delay between the 50% point of the rising edge of the

ENCODE command and the instant at which the analog input

is sampled.

Aperture Uncertainty (Jitter)

The sample-to-sample variation in aperture delay.

Differential Analog Input Resistance, Differential Analog

Input Capacitance, and Differential Analog Input Impedance

The real and complex impedances measured at each analog

input port. The resistance is measured statically and the

capacitance and differential input impedances are measured

with a network analyzer.

Differential Analog Input Voltage Range

The peak-to-peak differential voltage that must be applied to

the converter to generate a full-scale response. Peak differential

voltage is computed by observing the voltage on a single pin

and subtracting the voltage from the other pin, which is 180°

out of phase. Peak-to-peak differential is computed by rotating the

input phase 180° and taking the peak measurement again. The

difference is then computed between both peak measurements.

Differential Nonlinearity

The deviation of any code width from an ideal 1 LSB step.

Encode Pulse Width/Duty Cycle

Pulse width high is the minimum amount of time that the

ENCODE pulse should be left in the Logic 1 state to achieve

rated performance; pulse width low is the minimum time

ENCODE pulse should be left in a low state. Optimum

performance is achieved using a 50% duty cycle.

Full-Scale Input Power

Expressed in dBm. Computed using the following equation:

⎥

⎦

⎤

⎢

⎣

⎡

−

001

log

Input

Scale

Full

rms

Scale

Full

POWER

Harmonic Distortion, Second

The ratio of the rms signal amplitude to the rms value of the

second harmonic component, reported in dBc.

Harmonic Distortion, Third

The ratio of the rms signal amplitude to the rms value of the

third harmonic component, reported in dBc.

Integral Nonlinearity

The deviation of the transfer function from a reference line

measured in fractions of 1 LSB using a best straight line

determined by a least-square curve fit.

Minimum Conversion Rate

The encode rate at which the SNR of the lowest analog signal

frequency drops by no more than 3 dB below the guaranteed limit.

Maximum Conversion Rate

The encode rate at which parametric testing is performed.

Noise (for Any Range Within the ADC)

⎟

⎠

⎞

⎜

⎝

⎛

−

001

dBFS

dBc

dBm

NOISE

Signal

SNR

where:

is the input impedance.

is the full scale of the device for the frequency in question.

SNR

is the value for the particular input level.

Signal

is the signal level within the ADC reported in dB below

full scale.

VNOISE includes both thermal and quantization noise.

Output Propagation Delay

The delay between a differential crossing of ENCODE and

ENCODE, and the time when all output data bits are within

valid logic levels.

Power Supply Rejection Ratio

The ratio of a change in input offset voltage to a change in

power supply voltage.

Signal-to-Noise and Distortion (SINAD)

The ratio of the rms signal amplitude (set 1 dB below full scale)

to the rms value of the sum of all other spectral components,

including harmonics, but excluding dc.

Signal-to-Noise Ratio (Without Harmonics)

The ratio of the rms signal amplitude (set at 1 dB below full

scale) to the rms value of the sum of all other spectral

components, excluding the first five harmonics and dc.

AD6644ST/PCBZ 数据表(PDF) 14 Page - Analog Devices

AD6644ST/PCBZ 数据表(HTML) 14 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

数据表下载