AD6654/PCB Analog Devices Inc, AD6654/PCB Datasheet - Page 26

• Manufacturer Part Number: AD6654/PCB
• Description: BOARD EVALUATION FOR AD6654
• Manufacturer: Analog Devices Inc

Specifications of AD6654/PCB

• Module/board Type: Evaluation Board
• For Use With/related Products: AD6554
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

AD6654
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.
Differential Analog Input Resistance,
Capacitance, and 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 inputs phase 180° and taking the peak measurement again.
Then the difference is computed between both peak
measurements.
Encode Pulse Width/Duty Cycle
Pulse width high is the minimum amount of time that the
ENCODE pulse should be left in Logic 1 state to achieve the
rated performance. Pulse width low is the minimum time
ENCODE pulse should be left in the low state. Several internal
timing parameters are a function of t
performance will be achieved with 50/50 duty cycle.
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.
Full-Scale Input Power
Expressed in dBm. Computed using the following equation:
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
Encode rate at which parametric testing is performed.
Power
FULL
SCALE
=
10
log
⎛
⎜
⎜
⎜
⎜
⎜
⎜
⎝
V
2
ENCL
FULL
Z
. 0
INPUT
and t
001
SCALE
ENCH
RMS
, optimum
⎞
⎟
⎟
⎟
⎟
⎟
⎟
⎠
Rev. 0 | Page 26 of 88
where Z is the input impedance, FS is the full scale of the device
for the frequency in question, SNR is the value for the particular
input level, and SIGNAL is the signal level within the ADC
reported in dB below full scale. This value includes both
thermal and quantization noise.
Power-Supply Rejection Ratio
The ratio of a change in input offset voltage to a change in
power-supply voltage.
Power-Supply Rise Time
The time from when the dc supply is initiated until the supply
output reaches the minimum specified operating voltage for the
AD6654, measured at the supply pin(s) of the AD6654.
Processing Gain
When the tuned channel occupies less bandwidth than the
input signal, this rejection of out-of-band noise is referred to as
processing gain. By using large decimation factors, processing
gain can improve the SNR of the ADC by 15 dB or more. Use
the following equation to estimate processing gain:
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.
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 might, or might not be, a harmonic. SFDR can be reported
in dBc (degrades as signal level is lowered), or dBFS (always
related back to converter full scale).
Two-Tone Intermodulation Distortion Rejection
The ratio of the rms value of either input tone to the rms value
of the worst third-order intermodulation product, in dBc.
Two-Tone SFDR
Ratio of the rms value of either input tone to the rms value of
the peak spurious component. The peak spurious component
might, or might not be, an IMD product. SFDR can be reported
in dBc (degrades as signal level is lowered), or in dBFS (always
related back to converter full scale).
Worst Other Spur
Ratio of the rms signal amplitude to the rms value of the worst
spurious component (excluding the second and third harmonic)
reported in dBc.
Noise for Any Range Within the ADC
V
Processing
NOISE
=
_
Z
Gain
×
10
⎛
⎜
⎝
=
FS
10
dBm
log
−
⎡
⎢
⎣
SNR
Filter
Sample
dBc
10
−
_
SIGNAL
Bandwidth
_
Rate
dBFS
2 /
⎞
⎟
⎠
⎤
⎥
⎦