AD7294BSUZ Analog Devices Inc, AD7294BSUZ Datasheet - Page 19

• Manufacturer Part Number: AD7294BSUZ
• Description: IC ADC 12BIT W/DAC/TEMP 64TQFP
• Manufacturer: Analog Devices Inc
• Type: ADC, DACr

Specifications of AD7294BSUZ

• Resolution (bits): 12 b
• Data Interface: Serial
• Sampling Rate (per Second): 22.22k
• Voltage Supply Source: Analog and Digital
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -55°C ~ 150°C
• Mounting Type: Surface Mount
• Package / Case: 64-TQFP, 64-VQFP
• Sampling Rate: 22.22kSPS
• Input Channel Type: Differential, Single Ended
• Supply Voltage Range - Digital: 4.5V To 5.5V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TERMINOLOGY
DAC TERMINOLOGY
Relative Accuracy
For the DAC, relative accuracy or integral nonlinearity (INL) is
a measure of the maximum deviation, in LSBs, from a straight
line passing through the endpoints of the DAC transfer function.
Differential Nonlinearity
Differential nonlinearity (DNL) is the difference between the
measured change and the ideal 1 LSB change between any two
adjacent codes. A specified differential nonlinearity of ±1 LSB
maximum ensures monotonicity. This DAC is guaranteed mono-
tonic by design.
Zero Code Error
Zero code error is a measure of the output error when zero code
(0x0000) is loaded to the DAC register. Ideally, the output
should be 0 V. The zero code error is always positive in the
AD7294 because the output of the DAC cannot go below 0 V.
Zero code error is expressed in mV.
Full-Scale Error
Full-scale error is a measure of the output error when full-scale
code (0xFFFF) is loaded to the DAC register. Ideally, the output
should be V
Gain Error
Gain error is a measure of the span error of the DAC. It is the
deviation in slope of the DAC transfer characteristic from ideal,
expressed as a percent of the full-scale range.
Total Unadjusted Error
Total unadjusted error (TUE) is a measure of the output error,
taking all of the various errors into account.
Zero Code Error Drift
Zero code error drift is a measure of the change in zero code
error with a change in temperature. It is expressed in µV/°C.
Gain Error Drift
Gain error drift is a measure of the change in gain error with
changes in temperature. It is expressed in (ppm of full-scale
range)/°C.
ADC TERMINOLOGY
Signal-to-Noise and Distortion Ratio (SINAD)
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
DD
− 1 LSB. Full-scale error is expressed in mV.
S
/2), excluding dc. The
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ratio is 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
Thus, the SINAD is 74 dB for an ideal 12-bit converter.
Total Harmonic Distortion (THD)
The ratio of the rms sum of harmonics to the fundamental. For
the AD7294, it is defined as
where V
V
sixth harmonics.
Peak Harmonic or Spurious Noise
The ratio of the rms value of the next largest component in the
ADC output spectrum (up to f
value of the fundamental. Typically, 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.
Integral Nonlinearity
The maximum deviation from a straight line passing through
the endpoints of the ADC transfer function. The endpoints are
zero scale, a point 1 LSB below the first code transition, and full
scale, a point 1 LSB above the last code transition.
Differential Nonlinearity
The difference between the measured and the ideal 1 LSB
change between any two adjacent codes in the ADC.
Offset Error
The deviation of the first code transition (00…000) to
(00…001) from the ideal—that is, AGND + 1 LSB.
Offset Error Match
The difference in offset error between any two channels.
Gain Error
The deviation of the last code transition (111…110) to
(111…111) from the ideal (that is, REF
offset error has been adjusted out.
Gain Error Match
The difference in gain error between any two channels.
4
, V
Signal-to-(Noise + Distortion) = (6.02 N + 1.76) dB
THD
5
, and V
1
is the rms amplitude of the fundamental and V
(
dB
6
)
are the rms amplitudes of the second through
=
20
log
V
2
2
+
V
S
3
/2 and excluding dc) to the rms
2
+
V
V
1
4
2
+
IN
V
− 1 LSB) after the
5
2
+
V
6
2
AD7294
2
, V
3
,