ds1868e-50t-r Maxim Integrated Products, Inc., ds1868e-50t-r Datasheet - Page 6

• Manufacturer Part Number: ds1868e-50t-r
• Description: Ds1868 Dual Digital Potentiometer Chip
• Manufacturer: Maxim Integrated Products, Inc.

ABSOLUTE AND RELATIVE LINEARITY
Absolute linearity is defined as the difference between the actual measured output voltage and the
expected output voltage. Figure 5 presents the test circuit used to measure absolute linearity. Absolute
linearity is given in terms of a minimum increment or expected output when the wiper is moved one
position. In the case of the test circuit, a minimum increment (MI) or one LSB would equal 5/256 volts.
The equation for absolute linearity is given as follows:
(1)
Relative linearity is a measure of error between two adjacent wiper position points and is given in terms
of MI by equation (2).
(2)
Figure 6 is a plot of absolute linearity and relative linearity versus wiper position for the DS1868 at 25 C.
The specification for absolute linearity of the DS1868 is 0.75 MI typical. The specification for relative
linearity of the DS1868 is 0.3 MI typical.
LINEARITY MEASUREMENT CONFIGURATION Figure 5
ABSOLUTE LINEARITY
RELATIVE LINEARITY
AL={V
RL={V
O
(actual) - V
O
(n+1) - V
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O
(expected)}/MI
O
(n)}/MI
DS1868