Agilent Technologies 93000 SOC Series Training Manual page 256

Lesson 6 – Executing the DAC Linearity Test
LSB = Least
Significant Bit
Differential Non-Linearity can be calculated using the end point method, zero-
point method, or minimum root mean square method. All three methods use
the same formula. Only the definition of the DeviceLSB varies from method to
method.
Calculation of DAC DNL
The DeviceLSB is the analog output voltage step which
corresponds to a digital input step of 1 digit. Its calculation
depends on the chosen calculation method.
The software provides three methods for calculating the DeviceLSB
and hence the DNL:
End point method –
assumes a straight line between
first and last sample
Zero point method –
assumes that the middle sample is
correct and then minimizes the
mean error
Minimum RMS method –
minimizes the mean, averaged
deviation
Reconstruction of the "ideal" DAC Transfer Curve
The end point method assumes a straight line between the first
and last measured value.
256
n
where i = 0, 1, 2, ... 2 –2
Discrete Analog
Output Voltage
Digital Input code
Discrete Analog
Output Voltage
V[n /2]
s
Digital Input code
Discrete Analog
Output Voltage
Digital Input code