HI5714/6CB INTERSIL [Intersil Corporation], HI5714/6CB Datasheet - Page 11

• Manufacturer Part Number: HI5714/6CB
• Description: 8-Bit, 40/60/75/80 MSPS A/D Converter
• Manufacturer: INTERSIL [Intersil Corporation]

Timing Definitions
Aperture Delay: Aperture delay is the time delay between
the external sample command (the rising edge of the clock)
and the time at which the signal is actually sampled. This
delay is due to internal clock path propagation delays.
Aperture Jitter: This is the RMS variation in the aperture
delay due to variation of internal clock path delays.
Data Latency
After the analog sample is taken, the data on the bus is out-
put at the next rising edge of the clock. This is due to the out-
put latch of the converter. This delay is specified as the data
latency. After the data latency time, the data representing
each succeeding sample is output at the following clock
pulse. The digital data lags the analog input by 1 cycle.
Static Performance Definitions
Offset Error and Full-Scale Error use a measured value of
the external voltage reference to determine the ideal plus
and minus full-scale values. The results are all displayed in
LSBs.
Bottom Offset Voltage (V
The first code transition should occur at a level 0.5 LSB
above the negative full-scale. Bottom offset voltage is
defined as the deviation of the actual code transition from
this point.
Top Offset Voltage (V
The last code transition should occur for a analog input that
is 1.5 LSBs below positive full-scale. Top Offset Voltage is
defined as the deviation of the actual code transition from
this point.
Differential Linearity Error (DNL)
DNL is the worst case deviation of a code width from the
ideal value of 1 LSB. The converter is guaranteed to have no
missing codes.
Integral Linearity Error (INL)
INL is the worst case deviation of a code center from a best
fit straight line calculated from the measured data.
OT
)
OB
)
HI5714
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Dynamic Performance Definitions
Fast Fourier Transform (FFT) techniques are used to evalu-
ate the dynamic performance of the HI5714. A low distortion
sine wave is applied to the input, it is sampled, and the out-
put is stored in RAM. The data is then transformed into the
frequency domain with a 2048 point FFT and analyzed to
evaluate the dynamic performance of the A/D. The sine wave
input to the part is 0.5dB down from full scale for these tests.
The distortion numbers are quoted in dBc (decibels with
respect to carrier) and DO NOT include any correction fac-
tors for normalizing to full scale.
Signal-to-Noise Ratio (SNR)
SNR is the measured RMS signal to RMS noise at a speci-
fied input and sampling frequency. The noise is the RMS
sum of all of the spectral components except the fundamen-
tal and the first five harmonics.
Signal-to-Noise + Distortion Ratio (SINAD)
SINAD is the measured RMS signal to RMS sum of all other
spectral components below the Nyquist frequency excluding
DC.
Effective Number Of Bits (ENOB)
The effective number of bits (ENOB) is derived from the
SINAD data. ENOB is calculated from:
ENOB = (SINAD - 1.76) / 6.02
2nd and 3rd Harmonic Distortion
This is the ratio of the RMS value of the 2nd and 3rd
harmonic component respectively to the RMS value of the
measured input signal.
Full Power Input Bandwidth
Full power bandwidth is the frequency at which the ampli-
tude of the digitally reconstructed output has decreased 3dB
below the amplitude of the input sine wave. The input sine
wave has a peak-to-peak amplitude equal to the difference
between the top reference voltage input and the bottom ref-
erence voltage input. The bandwidth given is measured at
the specified sampling frequency.