X9252 Datasheet, PDF (9/21 Pages) Xicor Inc. – Quad Digitally-Controlled (XDCP) potentiometer

X9252
PIN DESCRIPTIONS
Bus Interface Pins
SERIAL DATA INPUT/OUTPUT (SDA)
The SDA is a bidirectional serial data input/output pin for
the 2-wire interface. It receives device address, operation
code, wiper register address and data from a 2-wire
external master device at the rising edge of the serial
clock SCL, and it shifts out data after each falling edge of
the serial clock SCL.
SDA requires an external pull-up resistor, since it’s an
open drain output.
SERIAL CLOCK (SCL)
This input is the serial clock of the 2-wire and Up/Down
interface.
DEVICE ADDRESS (A2–A0)
The Address inputs are used to set the least significant
3 bits of the 8-bit 2-wire interface slave address. A
match in the slave address serial data stream must be
made with the Address input pins in order to initiate
communication with the X9252. A maximum of 8
devices may occupy the 2-wire serial bus.
CHIP SELECT (CS)
When the CS pin is low, increment or decrement
operations are possible using the SCL and U/D pins.
The 2-wire interface is disabled at this time. When CS
is high, the 2-wire interface is enabled.
UP OR DOWN CONTROL (U/D)
The U/D input pin is held HIGH during increment oper-
ations and held LOW during decrement operations.
DCP SELECT (DS1-DS0)
The DS1-DS0 select one of the four DCPs for an Up/
Down interface operation.
HARDWARE WRITE PROTECT INPUT (WP)
When the WP pin is set low, “write” operations to non
volatile DCP Data Registers are disabled. This
includes both 2-wire interface non-volatile “Write”, and
Up/Down interface “Store” operations.
DCP Pins
R_H0, R_L0, R_H1, R_L1, R_H2, R_L2, R_H3, AND R_L3
These pins are equivalent to the terminal connections
on mechanical potentiometers. Since there are 4
DCPs, there is one set of R_H and R_L for each DCP.
R_W0, R_W1, R_W2, AND R_W3
The wiper pins are equivalent to the wiper terminal of
mechanical potentiometers. Since there are four
DCPs, there are 4 R_W pins.
REV 1.4.1 7/29/03
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