AD5301/AD5311/AD5321 Data Sheet
Rev. C | Page 8 of 24
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 actual endpoints of the DAC transfer
function. Typical INL vs. code plots can be seen in Figure 5 to
Figure 7.
Differential Nonlinearity (DNL)
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 monotonic-
ity. These DACs are guaranteed monotonic by design over all
codes. Typical DNL vs. code plots can be seen in Figure 8 to
Figure 10.
Zero-Code Error
Zero-code error is a measure of the output error when zero
code (0x00) is loaded to the DAC register. Ideally, the output
should be 0 V. The zero-code error of the AD5301/AD5311/
AD5321 is always positive because the output of the DAC
cannot go below 0 V, due to a combination of the offset errors
in the DAC and output amplifier. It is expressed in millivolts
(see Figure 12).
Full-Scale Error (FSR)
Full-scale error is a measure of the output error when full
scale is loaded to the DAC register. Ideally, the output should
be V
DD
– 1 LSB. Full-scale error is expressed in percent of FSR.
A plot can be seen in Figure 12.
Gain Error
Gain error is a measure of the span error of the DAC. It is the
deviation in slope of the actual DAC transfer characteristic from
the ideal expressed as a percentage of the full-scale range.
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.
Major Code Transition Glitch Energy
Major code transition glitch energy is the energy of the impulse
injected into the analog output when the code in the DAC register
changes state. It is normally specified as the area of the glitch in
nV-s and is measured when the digital code is changed by 1 LSB
at the major carry transition (011 . . . 11 to 100 . . . 00 or 100 . . . 00
to 011 . . . 11).
Digital Feedthrough
Digital feedthrough is a measure of the impulse injected into
the analog output of the DAC from the digital input pins of the
device, but is measured when the DAC is not being written to. It
is specified in nV-s and is measured with a full-scale change on
the digital input pins, that is, from all 0s to all 1s and vice versa.
