EVAL-AD7723CBZ Analog Devices Inc, EVAL-AD7723CBZ Datasheet - Page 14

• Manufacturer Part Number: EVAL-AD7723CBZ
• Description: BOARD EVALUATION FOR AD7723
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD7723CBZ

• Number Of Adc's: 1
• Number Of Bits: 16
• Sampling Rate (per Second): 1.2M
• Data Interface: Serial, Parallel
• Inputs Per Adc: 1 Differential
• Input Range: ±VREF
• Power (typ) @ Conditions: 475mW @ 1.2MSPS
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: AD7723
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD7723
TERMINOLOGY
Signal-to-Noise Ratio (SNR)
SNR is the measured signal-to-noise ratio at the output of the
ADC. The signal is the rms magnitude of the fundamental.
Noise is the rms sum of all of the nonfundamental signals up to
half the output data rate (F
evaluated by applying a low noise, low distortion sine wave
signal to the input pins. By generating a fast fourier transform
(FFT) plot, the SNR data can then be obtained from the output
spectrum.
Total Harmonic Distortion (THD)
THD is the ratio of the rms sum of the harmonics to the rms
value of the fundamental. THD is defined as
where V
V
sixth harmonics. The THD is also derived from the FFT plot of
the ADC output spectrum.
Spurious-Free Dynamic Range (SFDR)
Defined as the difference, in dB, between the peak spurious or
harmonic component in the ADC output spectrum (up to F
and excluding dc) and the rms value of the fundamental.
Normally, the value of this specification is determined by the
largest harmonic in the output spectrum of the FFT. For input
signals whose second harmonics occur in the stop-band region
of the digital filter, the spur in the noise floor limits the SFDR.
Pass-Band Ripple
The frequency response variation of the AD7723 in the defined
pass-band frequency range.
Pass-Band Frequency
The frequency up to which the frequency response variation is
within the pass-band ripple specification.
Cutoff Frequency
The frequency below which the AD7723’s frequency response
will not have more than 3 dB of attenuation.
Stop-Band Frequency
The frequency above which the AD7723’s frequency response
will be within its stop-band attenuation.
Stop-Band Attenuation
The AD7723’s frequency response will not have less than 90 dB
of attenuation in the stated frequency band.
4
, V
THD
5
, and V
1
is the rms amplitude of the fundamental, and V
= 20log
6
are the rms amplitudes of the second through
V
2
2
+
V
O
/2), excluding dc. The ADC is
3
2
+
V
V
1
4
2
+
V
5
2
+
V
6
2
2
, V
O
Rev. C | Page 14 of 32
3
/2
,
Integral Nonlinearity
This is the maximum deviation of any code from a straight line
passing through the endpoints of the transfer function. The
endpoints of the transfer function are minus full scale, a point
0.5 LSB below the first code transition (100 . . . 00 to 100 . . . 01
in bipolar mode, 000 . . . 00 to 000 . . . 01 in unipolar mode),
and plus full scale, a point 0.5 LSB above the last code transition
(011 . . . 10 to 011 . . . 11 in bipolar mode, 111 . . . 10 to 111 . . .
11 in unipolar mode). The error is expressed in LSBs.
Differential Nonlinearity
This is the difference between the measured and the ideal 1 LSB
change between two adjacent codes in the ADC.
Common-Mode Rejection Ratio
The ability of a device to reject the effect of a voltage applied to
both input terminals simultaneously—often through variation
of a ground level—is specified as a common–mode rejection
ratio. CMRR is the ratio of gain for the differential signal to the
gain for the common-mode signal.
Unipolar Offset Error
Unipolar offset error is the deviation of the first code transition
(10 . . . 000 to 10 . . . 001) from the ideal differential voltage
(VIN(+) – VIN(–)+ 0.5 LSB) when operating in the unipolar
mode.
Bipolar Offset Error
This is the deviation of the midscale transition code (111 . . . 11
to 000 . . . 00) from the ideal differential voltage (VIN(+) –
VIN(–) – 0.5 LSB) when operating in the bipolar mode.
Gain Error
The first code transition should occur at an analog value ½ LSB
above –full scale. The last transition should occur for an analog
value 1 ½ LSB below the nominal full scale. Gain error is the
deviation of the actual difference between first and last code
transitions and the ideal difference between first and last code
transitions.