RHF1401_12 Datasheet, PDF (36/42 Pages) STMicroelectronics – Rad-hard 14-bit 30 Msps A/D converter

Definitions of specified parameters
4
Definitions of specified parameters
RHF1401
4.1
Static parameters
Differential non-linearity (DNL)
The average deviation of any output code width from the ideal code width of 1 LSB.
Integral non-linearity (INL)
An ideal converter exhibits a transfer function that is a straight line from the starting code to
the ending code. The INL is the deviation from this ideal line for each transition.
4.2
Dynamic parameters
Spurious free dynamic range (SFDR)
The ratio between the power of the worst spurious signal (not always a harmonic) and the
amplitude of the fundamental tone (signal power) over the full Nyquist band.
Expressed in dBc.
Total harmonic distortion (THD)
The ratio of the rms sum of the first five harmonic distortion components to the rms value of
the fundamental line. Expressed in dB.
Signal to noise ratio (SNR)
The ratio of the rms value of the fundamental component to the rms sum of all other spectral
components in the Nyquist band (F_s/ 2) excluding DC, fundamental and the first five
harmonics. Reported in dB.
Signal-to-noise and distortion ratio (SINAD)
A similar ratio to the SNR but that includes the harmonic distortion components in the noise
figure (not the DC signal). Expressed in dB. From SINAD, the effective number of bits
(ENOB) can easily be deduced using the formula:
SINAD = 6.02× ENOB + 1.76 dB
When the analog input signal is not full-scale (FS) but has an A₀ amplitude, the SINAD
expression becomes:
SINAD = 6.02× ENOB + 1.76 dB + 20 log (A₀ / FS)
Analog input bandwidth
The maximum analog input frequency at which the spectral response of a full power signal
is reduced by 3 dB. Higher values can be achieved with smaller input levels.
Pipeline delay
The delay between the initial sample of the analog input and the availability of the
corresponding digital data output on the output bus. Also called data latency. Expressed as
a number of clock cycles.
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