AD5446 Analog Devices, AD5446 Datasheet - Page 14

• Manufacturer Part Number: AD5446
• Description: 14-Bit High Bandwidth Multiplying DAC with Serial Interface
• Manufacturer: Analog Devices

Specifications of AD5446

• Resolution (bits): 14bit
• Dac Update Rate: 2.7MSPS
• Dac Settling Time: 80ns
• Max Pos Supply (v): +5.5V
• Single-supply: Yes
• Dac Type: Current Out
• Dac Input Format: Ser,SPI

AD5444/AD5446
TERMINOLOGY
Relative Accuracy or Integral Nonlinearity
Relative accuracy or integral nonlinearity is a measure of the
maximum deviation from a straight line passing through the
endpoints of the DAC transfer function. It is measured after
adjusting for zero scale and full scale and is normally expressed
in LSBs or as a percentage of full-scale reading.
Differential Nonlinearity
Differential nonlinearity 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
over the operating temperature range ensures monotonicity.
Gain Error
Gain error or full-scale error is a measure of the output error
between an ideal DAC and the actual device output. For this
DAC, ideal maximum output is V
DAC is adjustable to zero with external resistance.
Output Leakage Current
Output leakage current is current that flows in the DAC ladder
switches when the ladder is turned off. For the I
be measured by loading all 0s to the DAC and measuring the
I
the DAC is loaded with all 1s.
Output Capacitance
Capacitance from I
Output Current Settling Time
The amount of time it takes for the output to settle to a speci-
fied level for a full-scale input change. For this device, it is
specified with a 100 Ω resistor to ground. The settling time
specification includes the digital delay from the SYNC rising
edge to the full-scale output change.
Digital-to-Analog Glitch Impulse
The amount of charge injected from the digital inputs to the
analog output when the inputs change state. This is normally
specified as the area of the glitch in either picoamps per second
or nanovolts per second, depending upon whether the glitch is
measured as a current or voltage signal.
OUT
1 current. Minimum current flows in the I
OUT
1 or I
OUT
2 to AGND.
REF
− 1 LSB. Gain error of the
OUT
OUT
2 line when
1 line, it can
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Digital Feedthrough
When the device is not selected, high frequency logic activ-
ity on the device’s digital inputs can be capacitively coupled
through the device to show up as noise on the I
pins and, subsequently, into the following circuitry. This noise is
digital feedthrough.
Multiplying Feedthrough Error
Multiplying feedthrough error is due to capacitive feedthrough
from the DAC reference input to the DAC I
0s are loaded to the DAC.
Total Harmonic Distortion (THD)
The DAC is driven by an ac reference. The ratio of the rms sum
of the harmonics of the DAC output to the fundamental value is
the THD. Usually only the lower-order harmonics, such as second
to fifth, are included.
Digital Intermodulation Distortion
Second-order intermodulation (IMD) measurements are the
relative magnitudes of the fa and fb tones digitally generated by
the DAC and the second-order products at 2fa − fb and 2fb − fa.
Compliance Voltage Range
The maximum range of (output) terminal voltage for which
the device provides the specified characteristics.
Spurious-Free Dynamic Range (SFDR)
The usable dynamic range of a DAC before spurious noise
interferes or distorts the fundamental signal. SFDR is the
measure of difference in amplitude between the fundamental
and the largest harmonically or nonharmonically related spur
from dc to full Nyquist bandwidth (half the DAC sampling
rate or f
an arbitrary window size, in this case 50% of the fundamental.
Digital SFDR is a measure of the usable dynamic range of the
DAC when the signal is a digitally generated sine wave.
THD
S
/2). Narrow-band SFDR is a measure of SFDR over
=
20
log
V
2
2
+
V
3
2
V
+
1
V
4
2
+
V
5
2
OUT
1 line, when all
OUT
1 and I
OUT
2