Datasheet

AD5421 Data Sheet
Rev. G | Page 20 of 36
TERMINOLOGY
Total Unadjusted Error
Total unadjusted error (TUE) is a measure of the total output
error. TUE consists of INL error, offset error, gain error, and
output drift over temperature, in the case of maximum TUE.
TUE is expressed in % FSR.
Relative Accuracy or Integral Nonlinearity (INL) Error
Relative accuracy, or integral nonlinearity (INL) error, is a
measure of the maximum deviation in the output current from
a straight line passing through the endpoints of the transfer
function. INL error is expressed in % FSR.
Differential Nonlinearity (DNL) Error
Differential nonlinearity (DNL) error 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.
Offset Error
Offset error is a measure of the output error when zero code is
loaded to the DAC register and is expressed in % FSR.
Offset Error Temperature Coefficient (TC)
Offset error TC is a measure of the change in offset error with
changes in temperature and 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 function from the ideal
and is expressed in % FSR.
Gain Error Temperature Coefficient (TC)
Gain error TC is a measure of the change in gain error with
changes in temperature and is expressed in ppm FSR/°C.
Full-Scale Error
Full-scale error is a measure of the output error when full-scale
code is loaded to the DAC register and is expressed in % FSR.
Full-Scale Error Temperature Coefficient (TC)
Full-scale error TC is a measure of the change in full-scale error
with changes in temperature and is expressed in ppm FSR/°C.
Loop Compliance Voltage Headroom
Loop compliance voltage headroom is the minimum voltage
between the LOOP− and REG
IN
pins for which the output
current is equal to the programmed value.
Output Temperature Coefficient (TC)
Output TC is a measure of the change in the output current
at 12 mA with changes in temperature and is expressed in
ppm FSR/°C.
Voltage Reference Thermal Hysteresis
Voltage reference thermal hysteresis is the difference in output
voltage measured at +25°C compared to the output voltage
measured at +25°C after cycling the temperature from +25°C to
−40°C to +105°C and back to +25°C. The hysteresis is specified
for the first and second temperature cycles and is expressed in mV.
Voltage Reference Temperature Coefficient (TC)
Voltage reference TC is a measure of the change in the reference
output voltage with a change in temperature. The voltage refer-
ence TC is calculated using the box method, which defines the
TC as the maximum change in the reference output voltage over
a given temperature range. Voltage reference TC is expressed in
ppm/°C as follows:
6
10×








×
−
=
Temp_RangeV
VV
TC
REF_NOM
REF_MIN
REF_MAX
where:
V
REF_MAX
is the maximum reference output voltage measured
over the total temperature range.
V
REF_MIN
is the minimum reference output voltage measured
over the total temperature range.
V
REF_NOM
is the nominal reference output voltage, 2.5 V.
Temp_Range is the specified temperature range
(−40°C to +105°C).