Datasheet

AD5441
Rev. A | Page 10 of 16
TERMINOLOGY
Relative Accuracy (INL)
Relative accuracy or endpoint nonlinearity is a measure of the
maximum deviation from a straight line passing through the
endpoints of the DAC transfer function. It is measured after
adjusting for zero and full scale and is normally expressed in
LSBs or as a percentage of the full-scale reading.
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 over the operating
temperature range ensures monotonicity.
Gain Error
Gain error or full-scale error is a measure of the output error
between an ideal DAC and the actual device output. For these
DACs, ideal maximum output is V
REF
− 1 LSB. Gain error of the
DACs is adjustable to zero with external resistance.
Zero Scale Error
Calculated from worst-case R
REF
I
ZSE
(LSB) = (R
REF
× I
LKG
× 4096)/V
REF
.
Output Leakage Current
Output leakage current is the current that flows into the DAC
ladder switches when they are turned off. For the I
OUT
terminal,
it can be measured by loading all 0s to the DAC and measuring
the I
OUT
current.
Output Capacitance
Capacitance from I
OUT
1 to AGND.
Digital-to-Analog Glitch Impulse
The amount of charge injected from the digital inputs to the
analog output when the inputs change state. This is normally
specified as the area of the glitch in either pA-s or nV-s,
depending on whether the glitch is measured as a current or
voltage signal.
Digital Feedthrough
When the device is not selected, high frequency logic activity
on the digital inputs of the device may be capacitively coupled
through the device and produce noise on the I
OUT
pins. This
noise is coupled from the outputs of the device onto follow-on
circuitry. This noise is digital feedthrough.
Multiplying Feedthrough Error
This is the error due to capacitive feedthrough from the DAC
reference input to the DAC I
OUT
1 terminal when all 0s are
loaded to the DAC.
Total Harmonic Distortion (THD)
The DAC is driven by an ac reference. The ratio of the rms sum
of the harmonics of the DAC output to the fundamental value is
the THD. Usually only the lower order harmonics, such as
second to fifth, are included.
V1
V5V4V3V2
THD
2222
log20
+++
=
Compliance Voltage Range
The maximum range of (output) terminal voltage for which the
device provides the specified characteristics.
Output Noise Spectral Density
Calculation from
e
n
= √4KTRB
where:
K is Boltzmann Constant (J/°K).
R is resistance ().
T is the resistor temperature (°K).
B is the 1 Hz bandwidth.