DS1669

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Dual pushbutton mode of operation is entered when the DC input is floated on power-up. If interfacing

contact closure control inputs to digital logic, the DC input must be interfaced to an open drain drive

which is high impedance during power-up; see Figure 2B. This will prevent the device from entering a

single pushbutton mode of operation.

In dual pushbutton mode, each direction is controlled by the up contact (UC) and down contact (DC)

inputs, respectively. No wait states are required to change wiper direction in dual pushbutton mode. In

dual pushbutton mode, as the wiper position reaches the end of the potentiometer, the direction of wiper

movement will not change. Wiper position will remain at the potentiometers’ end until an opposite

direction input is given.

All contact closure control inputs, UC, DC, and D, are internally pulled-up by a 100 k

Ω=resistance. The

UC and DC inputs are internally debounced and require no external components for input signal

conditioning.