X9279 Datasheet, PDF (4/22 Pages) Xicor Inc. – Single Digitally-Controlled (XDCP) Potentiometer

X9279
PIN DESCRIPTIONS
Bus Interface Pins
SERIAL DATA INPUT/OUTPUT (SDA)
The SDA is a bidirectional serial data input/output pin
for a 2-Wire slave device and is used to transfer data
into and out of the device. It receives device address,
opcode, wiper register address and data sent from an
2-Wire master at the rising edge of the serial clock
SCL, and it shifts out data after each falling edge of
the serial clock SCL.
It is an open drain output and may be wire-ORed with
any number of open drain or open collector outputs.
An open drain output requires the use of a pull-up
resistor. For selecting typical values, refer to the
guidelines for calculating typical values on the bus
pull-up resistors graph.
SERIAL CLOCK (SCL)
This input is used by 2-Wire master to supply 2-Wire
serial clock to the X9279.
DEVICE ADDRESS (A2 - A0)
The Address inputs are used to set the least
significant 3 bits of the 8-bit slave address. A match in
the slave address serial data stream must be made
with the Address input in order to initiate
communication with the X9279. A maximum of 8
devices may occupy the 2-Wire serial bus.
Potentiometer Pins
R_H, R_L
The R_H and R_L pins are equivalent to the terminal
connections on a mechanical potentiometer.
R_W
The wiper pin is equivalent to the wiper terminal of a
mechanical potentiometer.
Bias Supply Pins
SYSTEM SUPPLY VOLTAGE (V_CC) AND SUPPLY
GROUND (V_SS)
The V_CC pin is the system supply voltage. The V_SS
pin is the system ground.
Other Pins
NO CONNECT
No connect pins should be left open. This pins are used
for Intersil manufacturing and testing purposes.
HARDWARE WRITE PROTECT INPUT (WP)
The WP pin when LOW prevents nonvolatile writes to
the Data Registers.
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FN8175.2
September 27, 2005