DS1801

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CASCADE OPERATION

A feature of the DS1801 is the ability to control multiple devices from a single processor. Multiple

DS1801s can be linked or daisy-chained as shown in Figure 4. As a data bit is entered into the I/O shift

of 50 nanoseconds.

multiple devices, the total number of bits sent is always 16 times the number of DS1801s in the daisy

chain.

of the first DS1801 thus allowing the controlling processor to read as well as write data or circularly

clock data through the daisy chain. The value of the feedback or isolation resistor should be in the range

from 2 to 10 kohms.

the isolation resistor. When the CLK input transitions low to high, bit 0 is loaded into the first position of

times the number of DS1801s in the daisy chain), the data has shifted completely around and back to its

the read occurred) is loaded into wiper-0 and wiper-1.

CASCADING MULTIPLE DEVICES Figure 4

Zero-Crossing Detection

The DS1801 provides a zero-crossing detection capability that minimizes any audible noise that may

result from sizable discrete wiper transitions when using the part in audio applications. The zero-crossing

detect feature allows independent wiper changes only when the two terminals of the potentiometer have

DS1801 has not detected a zero-crossing, the wiper position of the potentiometer(s) will change

detection crossing.