DS1868

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DS1868 ABSOLUTE AND RELATIVE LINEARITY Figure 6

TYPICAL APPLICATION CONFIGURATIONS

Figures 7 and 8 show two typical application configurations for the DS1868. By connecting the wiper

terminal of the part to a high impedance load, the effects of the wiper resistance is minimized, since the

wiper resistance can vary from 400 to 1000 ohms, depending on wiper voltage. Figure 7 presents the

device connected in a variable gain amplifier. The gain of the circuit on Figure 7 is given by the following

equation:

n

-

256

256

+

where n = 0 to 255

Figure 8 shows the device operating in a fixed gain attenuator where the potentiometer is used to

attenuate an incoming signal. Note the resistance R1 is chosen to be much greater than the wiper

resistance to minimize its effect on circuit gain.