Datasheet

AD420
Rev. H | Page 8 of 16
TERMINOLOGY
Resolution
For 16-bit resolution, 1 LSB = 0.0015% of the FSR. In the
4 mA–20 mA range 1 LSB = 244 nA.
Integral Nonlinearity
Analog Devices defines integral nonlinearity as the maximum
deviation of the actual, adjusted DAC output from the ideal
analog output (a straight line drawn from 0 to FS – 1 LSB) for
any bit combination. This is also referred to as relative accuracy.
Differential Nonlinearity
Differential nonlinearity is the measure of the change in the
analog output, normalized to full scale, associated with an LSB
change in the digital input code. Monotonic behavior requires
that the differential linearity error be greater than –1 LSB over
the temperature range of interest.
Monotonicity
A DAC is monotonic if the output either increases or remains
constant for increasing digital inputs with the result that the
output will always be a single-valued function of the input.
Gain Error
Gain error is a measure of the output error between an ideal
DAC and the actual device output with all 1s loaded after offset
error has been adjusted out.
Offset Error
Offset error is the deviation of the output current from its ideal
value expressed as a percentage of the fullscale output with all
0s loaded in the DAC.
Drift
Drift is the change in a parameter (such as gain and offset) over
a specified temperature range. The drift temperature coefficient,
specified in ppm/°C, is calculated by measuring the parameter
at T
MIN
, 25°C, and T
MAX
and dividing the change in the
parameter by the corresponding temperature change.
Current Loop Voltage Compliance
The voltage compliance is the maximum voltage at the I
OUT
pin for
which the output current will be equal to the programmed value.