DS1867 DALLAS [Dallas Semiconductor], DS1867 Datasheet - Page 8

• Manufacturer Part Number: DS1867
• Description: Dual Digital Potentiometer with EEPROM
• Manufacturer: DALLAS [Dallas Semiconductor]

DS1867
FIXED GAIN ATTENUATOR Figure 8
ABSOLUTE AND RELATIVE LINEARITY
Absolute linearity is defined as the difference between the actual measured output voltage and the
expected output voltage. Figure 9 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 position is moved
one position. In the case of the test circuit, a minimum increment (MI) would equal 10/512volts. The
equation for absolute linearity is given in equation (1).
Eq: (1) Absolute Linearity
AL = {Vo(actual)- Vo(expected)}/MI
Relative linearity is a measure of error between two adjacent wiper position points and is given in terms
of MI by equation (2).
Eq: (2) Relative Linearity
RL = {Vo(n+1) - Vo(n)}/MI
Figure 10 is a plot of absolute linearity and relative linearity versus wiper position for the DS1867 at
25 C. The specification for absolute linearity of the DS1867 is 0.75 MI typical. The specification for
relative linearity of the DS1867 is 0.30 MI typical.
LINEARITY MEASUREMENT CONFIGURATION Figure 9
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