X24128
Xicor E
2
PROMs are designed and tested for applica-
tions requiring extended endurance. Inherent data
retention is greater than 100 years.
PIN DESCRIPTIONS
Serial Clock (SCL)
The SCL input is used to clock all data into and out of
the device.
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
Pull-up resistor selection graph at the end of this data
sheet.
Device Select (S
0
, S
1
, S
2
)
The device select inputs (S
0
, S
1
, S
2
) are used to set
the first three bits of the 8-bit slave address. This
allows up to eight devices to share a common bus.
These inputs can be static or actively driven. If used
statically they must be tied to V
SS
or V
CC
as appro-
priate. If actively driven, they must be driven with
CMOS levels (driven to V
CC
or V
SS
).
Write Protect (WP)
The Write Protect input controls the Hardware Write
Protect feature. When held LOW, Hardware Write
Protection is disabled. When this input is held HIGH,
and the WPEN bit in the Write Protect Register is set
HIGH, the Write Protect Register is protected,
preventing changes to the Block Lock Protection and
WPEN bits.
.344”
PIN NAMES
Symbol
S
0
, S
1
, S
2
SDA
SCL
WP
V
SS
V
CC
NC
Description
Device Select Inputs
Serial Data
Serial Clock
Write Protect
Ground
Supply Voltage
No Connect
7027 FM T01
PIN CONFIGURATION
Not to scale
14 Lead SOIC
S0
S1
NC
NC
NC
S2
VSS
1
2
3
4
5
6
7
.244”
X24128
14
13
12
11
10
9
8
VCC
WP
NC
NC
NC
SCL
SDA
16 Lead SOIC
S0
S1
NC
.394”
NC
NC
NC
S2
VSS
1
2
3
4
5
6
7
8
.244”
X24128
16
15
14
13
12
11
10
9
VCC
WP
NC
NC
NC
NC
SCL
SDA
8 Lead PDIP
S0
.430”
S1
S2
VSS
1
2
3
4
.325”
X24128
8
7
6
5
VCC
WP
SCL
SDA
7027 FM 02
2
XICOR [ XICOR INC. ]
