AD9432

Rev. F | Page 11 of 16

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 a differential crossing of ENCODE and

ENCODE and the instant at which the analog input is sampled.

Aperture Uncertainty (Jitter)

The sample-to-sample variation in aperture delay.

Differential Nonlinearity (DNL)

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

Effective Number of Bits (ENOB)

The effective number of bits (ENOB) is calculated from the

measured SNR based on the following equation:

02

.

6

log

20

dB

76

.

1

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛

−

+

−

=

Amplitude

Input

Amplitude

Scale

Full

SNR

ENOB

MEASURED

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 the rated per-

formance. Pulse width low is the minimum amount of time that

the encode pulse should be left in the Logic 0 state. At a given clock

rate, these specifications define an acceptable encode duty cycle.

Harmonic Distortion

The ratio of the rms signal amplitude fundamental frequency

to the rms signal amplitude of a single harmonic component

(second, third, and so on); reported in dBc.

Integral Nonlinearity (INL)

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.

Maximum Conversion Rate

The maximum encode rate at which parametric testing is

performed.

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.

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 (PSRR)

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

power supply voltage.

Signal-to-Noise and Distortion (SINAD) Ratio

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 compo-

nents, including harmonics but excluding dc.

Signal-to-Noise Ratio (SNR)

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 com-

ponents, excluding the first five harmonics and dc.

Spurious-Free Dynamic Range (SFDR)

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

peak spurious spectral component. The peak spurious compo-

nent may or may not be a harmonic. May be reported in dBc

(degrades as signal level is lowered) or in dBFS (always related

back to converter full scale).

Two-Tone Intermodulation Distortion Rejection

value of the worst third-order intermodulation product;

Two-Tone SFDR

value of the peak spurious component. The peak spurious com-

ponent may or may not be an IMD product. May be reported in

dBc (degrades as signal level is lowered) or in dBFS (always

related back to converter full scale).

Worst Other Spur

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

worst spurious component (excluding the second-order and

third-order harmonic); reported in dBc.