ADN8810

Rev. 0 | Page 8 of 16

ADN8810 TERMINOLOGY

Relative Accuracy

Relative accuracy or integral nonlinearity (INL) is a measure of

the maximum deviation, in least significant bits (LSBs), from an

ideal line passing through the endpoints of the DAC transfer

function. Figure 5 shows a typical INL vs. code plot. The

ADN8810 INL is measured from 2% to 100% of the full-scale

(FS) output.

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. The ADN8810

is guaranteed monotonic by design. Figure 6 shows a typical

Offset Error

Offset error, or zero-code error, is an interpolation of the output

voltage at code 0x000 as predicted by the line formed from the

output voltages at code 0x040 (2% FS) and code 0xFFF (100%

FS). Ideally, the offset error should be 0 V. Offset error occurs

from a combination of the offset voltage of the amplifier and

offset errors in the DAC. It is expressed in LSBs.

Offset Drift

This is a measure of the change in offset error with a change in

temperature. It is expressed in (ppm of full-scale range)/°C.

Gain Error

Gain error is a measure of the span error of the DAC. It is the

deviation in slope of the output transfer characteristic from

ideal. The transfer characteristic is the line formed from the

output voltages at code 0x040 (2% FS) and code 0xFFF (100%

FS). It is expressed as a percent of the full-scale range.

Compliance Voltage

The maximum output voltage from the ADN8810 is a function

of output current and supply voltage. Compliance voltage

defines the maximum output voltage at a given current and

supply voltage to guarantee the device operates within its INL,

DNL, and gain error specifications.

Output Current Change vs. Output Voltage Change

This is a measure of the ADN8810 output impedance and is

similar to a load regulation spec in voltage references. For a

given code, the output current changes slightly as output voltage

increases. It is measured as an absolute value in (ppm of full-

scale range)/V.

INTERPOLATED

DAC CODE

OFFSET

ERROR

GAIN ERROR

PLUS

OFFSET ERROR

0xFFF

0x040

IDEAL

ACTUAL

(EXAGGERATED)

Figure 4. Output Transfer Function