REV. 0

AD5301/AD5311/AD5321

–6–

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 Figures 2

to 4.

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. These DACs are guaranteed

monotonic by design over all codes. Typical DNL vs. Code

plots can be seen in Figures 5 to 7.

ZERO CODE ERROR

Zero Code Error is a measure of the output error when zero

code (00H) 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 can-

not go below 0 V. It is due to a combination of the offset errors

in the DAC and output amplifier. It is expressed in mV, see

Figure 9.

FULL-SCALE ERROR

Full-Scale Error is a measure of the output error when full scale

– 1 LSB. Full-scale error is expressed in percent of FSR (full-

scale range). A plot can be seen in Figure 9.

GAIN ERROR

This is a measure of the span error of the DAC. It is the devia-

tion in slope of the actual DAC transfer characteristic from the

ideal expressed as a percentage of the full-scale range.

ZERO CODE ERROR DRIFT

This is a measure of the change in zero code error with a

change in temperature. It is expressed in

µV/°C.

GAIN ERROR DRIFT

This is a measure of the change in gain error with changes in tem-

perature. 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 im-

pulse 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-secs 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-secs and is measured with a full-scale change

on the digital input pins, i.e., from all 0s to all 1s and vice versa.