X9428
PIN DESCRIPTIONS
Host Interface Pins
Serial Clock (SCL)
The SCL input is used to clock data into and out of the
X9428.
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 the guidelines for calculating typical
values on the bus pull-up resistors graph.
Device Address (A
0
,
A
2
,
A
3
)
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 X9428. A maximum of 8
devices may occupy the 2-wire serial bus.
Potentiometer Pins
R
H
/V
H
, R
L
/V
L
The R
H
/V
H
and R
L
/V
L
inputs are equivalent to the
terminal connections on either end of a mechanical
potentiometer.
R
W
/V
W
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 Supply V+, V-
The Analog Supply V+, V- are the supply voltages for
the XDCP analog section.
PIN NAMES
Symbol
SCL
SDA
A0, A2, A3
R
H
/V
H
, V
L
/R
H
R
W
/V
W
WP
V+,V-
V
CC
V
SS
NC
Serial clock
Serial data
Device address
Potentiometer Pins
(terminal equivalent)
Potentiometer Pin (wiper equivalent)
Hardware write protection
Analog and voltage follower
System supply voltage
System ground
No connection
V
CC
A2
R
L
/V
L
R
H
/V
H
R
W
/V
W
SDA
WP
V
SS
1
2
3
4
5
6
7
8
X9428
PIN CONFIGURATION
DIP/SOIC
16
15
14
13
12
11
10
9
V+
NC
A0
NC
A3
SCL
NC
V-
TSSOP
A2
R
L
R
H
R
W
SDA
WP
V
SS
1
2
3
4
5
6
7
X9428
14
13
12
11
10
9
8
V
CC
V+
A0
NC
A3
SCL
V-
Description
4
FN8197.1
April 26, 2006
INTERSIL [ INTERSIL CORPORATION ]
