AD5791 Analog Devices, AD5791 Datasheet - Page 18

• Manufacturer Part Number: AD5791
• Manufacturer: Analog Devices

Specifications of AD5791

• Resolution (bits): 20bit
• Dac Update Rate: 1MSPS
• Dac Settling Time: 1µs
• Max Pos Supply (v): +16.5V
• Single-supply: No
• Dac Type: Unbuffered Vout
• Dac Input Format: Ser,SPI

AD5791
TERMINOLOGY
Relative Accuracy
Relative accuracy, or integral nonlinearity (INL), is a measure of
the maximum deviation, in LSB, from a straight line passing
through the endpoints of the DAC transfer function. A typical
INL error vs. code plot is shown in Figure 6.
Differential Nonlinearity (DNL)
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
ensures monotonicity. This DAC is guaranteed monotonic. A
typical DNL error vs. code plot is shown in Figure 10.
Linearity Error Long Term Stability
Linearity error long term stability is a measure of the stability of
the linearity of the DAC over a long period of time. It is specified
in LSB for a time period of 500 hours and 1000 hours at an
elevated ambient temperature.
Zero-Scale Error
Zero-scale error is a measure of the output error when zero-scale
code (0x00000) is loaded to the DAC register. Ideally, the output
voltage should be V
Zero-Scale Error Temperature Coefficient
Zero-scale error temperature coefficient is a measure of the
change in zero-scale error with a change in temperature. It is
expressed in ppm FSR/°C.
Full-Scale Error
Full-scale error is a measure of the output error when full-
scale code (0x3FFFF) is loaded to the DAC register. Ideally,
expressed in LSBs.
Full-Scale Error Temperature Coefficient
Full-scale error temperature coefficient is a measure of the
change in full-scale error with a change in temperature. It is
expressed in ppm FSR/°C.
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 in ppm of the full-scale range.
Gain Error Temperature Coefficient
Gain error temperature coefficient is a measure of the change in
gain error with a change in temperature. It is expressed in ppm
FSR/°C.
Midscale Error
Midscale error is a measure of the output error when midscale
code (0x20000) is loaded to the DAC register. Ideally, the output
voltage should be (V
expressed in LSBs.
the output voltage should be V
REFNS
REFPS
. Zero-scale error is expressed in LSBs.
− V
REFNS
REFPS
)/2 +V
− 1 LSB. Full-scale error is
REFNS
. Midscale error is
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Midscale Error Temperature Coefficient
Midscale error temperature coefficient is a measure of the
change in midscale error with a change in temperature. It is
expressed in ppm FSR/°C.
Output Slew Rate
Slew rate is a measure of the limitation in the rate of change of
the output voltage. The slew rate of the
is determined by the capacitive load presented to the V
capacitive load in conjunction with the 3.4 kΩ output impedance
of the
to 90% of the output voltage change and is expressed in V/μs.
Output Voltage Settling Time
Output voltage settling time is the amount of time it takes for
the output voltage to settle to a specified level for a specified
change in voltage. For fast settling applications, a high speed
buffer amplifier is required to buffer the load from the 3.4 kΩ
output impedance of the AD5791, in which case it is the
amplifier that determines the settling time.
Digital-to-Analog Glitch Impulse
Digital-to-analog glitch impulse is the impulse injected into the
analog output when the input code in the DAC register changes
state. It is specified as the area of the glitch in nV-sec and is
measured when the digital input code is changed by 1 LSB at
the major carry transition (see Figure 43).
Output Enabled Glitch Impulse
Output enabled glitch impulse is the impulse injected into the
analog output when the clamp to ground on the DAC output is
removed. It is specified as the area of the glitch in nV-sec (see
Figure 49).
Digital Feedthrough
Digital feedthrough is a measure of the impulse injected into
the analog output of the DAC from the digital inputs of the
DAC but is measured when the DAC output is not updated. It is
specified in nV-sec and measured with a full-scale code change
on the data bus, that is, from all 0s to all 1s, and vice versa.
Spurious Free Dynamic Range (SFDR)
Spurious free dynamic range is the usable dynamic range of a
DAC before spurious noise interferes or distorts the fundamental
signal. It is measured by the 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
digitally generated sine wave.
Total Harmonic Distortion (THD)
Total harmonic distortion is the ratio of the rms sum of the
harmonics of the DAC output to the fundamental value Only
the second to fifth harmonics are included.
AD5791
set the slew rate. Slew rate is measured from 10%
S
/2). SFDR is measured when the signal is a
AD5791
Data Sheet
output voltage
OUT
pin. The