AD7400AYRWZ-RL Analog Devices Inc, AD7400AYRWZ-RL Datasheet - Page 12

• Manufacturer Part Number: AD7400AYRWZ-RL
• Description: Isolated Sigma-Delta Modulator ADC I.C.
• Manufacturer: Analog Devices Inc
• Type: Modulatorr

Specifications of AD7400AYRWZ-RL

• Resolution (bits): 14 b
• Data Interface: Serial
• Voltage Supply Source: Single Supply
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sampling Rate (per Second): -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD7400A
TERMINOLOGY
Differential Nonlinearity
Differential nonlinearity is the difference between the measured
and the ideal 1 LSB change between any two adjacent codes in
the ADC.
Integral Nonlinearity
Integral nonlinearity is the maximum deviation from a straight
line passing through the endpoints of the ADC transfer function.
The endpoints of the transfer function are specified negative
full scale, −250 mV (V
positive full scale, +250 mV (V
the 16-bit level.
Offset Error
Offset is the deviation of the midscale code (Code 32,768 for
the 16-bit level) from the ideal V
Gain Error
Gain error includes both positive full-scale gain error and
negative full-scale gain error. Positive full-scale gain error is the
deviation of the specified positive full-scale code (58,366 for the
16-bit level) from the ideal V
offset error is adjusted out. Negative full-scale gain error is the
deviation of the specified negative full-scale code (7169 for the
16-bit level) from the ideal V
offset error is adjusted out. Gain error includes reference error.
Signal-to-Noise and Distortion (SINAD) Ratio
This ratio is the measured ratio of signal-to-noise and distortion
at the output of the ADC. The signal is the rms amplitude of the
fundamental. Noise is the sum of all nonfundamental signals up
to half the sampling frequency (f
dependent on the number of quantization levels in the digitization
process; the more levels, the smaller the quantization noise. The
theoretical signal-to-noise and distortion ratio for an ideal N-bit
converter with a sine wave input is given by
Therefore, for a 12-bit converter, SINAD is 74 dB.
Effective Number of Bits (ENOB)
The ENOB is defined by
Signal-to-Noise and Distortion = (6.02N + 1.76) dB
ENOB = (SINAD − 1.76)/6.02
IN
+ − V
IN
IN
IN
+ − V
+ − V
IN
−), Code 7169, and specified
+ − V
IN
S
/2), excluding dc. The ratio is
+ − V
IN
IN
− (+250 mV) after the
− (−250 mV) after the
IN
−), Code 58,366 for
IN
− (that is, 0 V).
Rev. B | Page 12 of 20
Total Harmonic Distortion (THD)
THD is the ratio of the rms sum of harmonics to the
fundamental. For the AD7400A, it is defined as
where:
V
V
through the sixth harmonics.
Peak Harmonic or Spurious Noise
Peak harmonic or spurious noise is defined as the ratio of the rms
value of the next largest component in the ADC output spectrum
(up to f
Normally, the value of this specification is determined by the
largest harmonic in the spectrum, but for ADCs where the
harmonics are buried in the noise floor, it is a noise peak.
Common-Mode Rejection Ratio (CMRR)
CMRR is defined as the ratio of the power in the ADC output at
±250 mV frequency, f, to the power of a 250 mV p-p sine wave
applied to the common-mode voltage of V
frequency f
where:
Pf is the power at frequency f in the ADC output.
Pf
Power Supply Rejection Ratio (PSRR)
Variations in power supply affect the full-scale transition but
not the converter linearity. PSRR is the maximum change in the
specified full-scale (±250 mV) transition point due to a change
in power supply voltage from the nominal value (see Figure 7).
Isolation Transient Immunity
The isolation transient immunity specifies the rate of rise/fall of
a transient pulse applied across the isolation boundary beyond
which clock or data is corrupted. (The AD7400A was tested using
a transient pulse frequency of 100 kHz.)
1
2
S
, V
is the rms amplitude of the fundamental.
is the power at frequency f
3
, V
CMRR (dB) = 10 log(Pf/Pf
S
THD
/2, excluding dc) to the rms value of the fundamental.
4
, V
S
5
as
(
, and V
dB
)
=
20
6
are the rms amplitudes of the second
log
V
2
S
2
in the ADC output.
+
V
S
)
3
2
+
V
V
1
4
2
IN
+
+ and V
V
5
2
+
V
IN
6
− of
2