X9258_13 Datasheet, PDF (3/19 Pages) Intersil Corporation – Low Noise/Low Power/2-Wire Bus/256 Taps

Pinout
X9258
X9258
(24 LD SOIC, TSSOP)
TOP VIEW
NC
A0
V_W3/R_W3
V_H3/R_H3
V_L3/R_L3
V+
V_CC
V_L0/R_L0
V_H0/R_H0
V_W0/R_W0
A2
WP
1
24
2
23
3
22
4
21
5
20
6
19
X9258
7
18
8
17
9
16
10
15
11
14
12
13
A3
SCL
V_L2/R_L2
V_H2/R_H2
V_W2/R_W2
V–
V_SS
V_W1/R_W1
V_H1/R_H1
V_L1/R_L1
A1
SDA
Pin Descriptions
Host Interface Pins
SERIAL CLOCK (SCL)
The SCL input is used to clock data into and out of the X9258.
SERIAL DATA (SDA)
SDA is a bidirectional pin used to transfer data into and out of
the device. 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 “Guidelines for Calculating
Typical Values of Bus Pull-Up Resistors” on page 10.
DEVICE ADDRESS (A₀ - A₃)
The Address inputs are used to set the least significant 4 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 X9258. A maximum
of 16 devices may occupy the 2-wire serial bus.
Potentiometer Pins
V_H/R_H (V_H0/R_H0 - V_H3/R_H3), V_L/R_L (V_L0/R_L0 - V_L3/R_L3)
The V_H/R_H and V_L/R_L inputs are equivalent to the terminal
connections on either end of a mechanical potentiometer.
V_W/R_W (V_W0/R_W0 - V_W3/R_W3)
The wiper outputs are equivalent to the wiper output of a
mechanical potentiometer.
Hardware Write Protect Input (WP)
The WP pin when low prevents nonvolatile writes to the Data
Registers.
Analog Supplies V+, V-
The Analog Supplies V+, V- are the supply voltages for the
DCP analog section.
3
Pin Names
SYMBOL
SCL
SDA
A0 thru A3
V_H0/R_H0 thru V_H3/R_H3,
V_L0/R_L0 thru V_L3/R_L3
V_W0/R_W0 thru V_W3/R_W3
WP
V+, V-
DESCRIPTION
Serial Clock
Serial Data
Device Address
Potentiometer Pins
(terminal equivalent)
Potentiometers Pins
(wiper equivalent)
Hardware Write Protection
Analog Supplies
V_CC
V_SS
NC
System Supply Voltage
System Ground
No Connection (Allowed)
Principles Of Operation
The X9258 is a highly integrated microcircuit incorporating
four resistor arrays and their associated registers and
counters and the serial interface logic providing direct
communication between the host and the DCP
potentiometers.
Serial Interface (2-Wire)
The X9258 supports a bidirectional bus oriented protocol.
The protocol defines any device that sends data onto the
bus as a transmitter and the receiving device as the receiver.
The device controlling the transfer is a master and the
device being controlled is the slave. The master will always
initiate data transfers and provide the clock for both transmit
and receive operations. Therefore, the X9258 will be
considered a slave device in all applications.
FN8168.6
December 15, 2011