
PRODUCT SELECTION GUIDE
PARAMETER
WS57C256F-55
WS57C256F-70
Address Access Time (Max)
55 ns
70 ns
Output Enable Time (Max)
25 ns
30 ns
WS57C256F
V
CC
A14
A13
A8
A9
A11
OE
A10
CE/PGM
O
7
O
6
O
5
O
4
O
3
V
PP
A
12
A
7
A
6
A
5
A
4
A
3
A
2
A
1
A
0
O
0
O
1
O
2
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
A
8
A
9
A
11
NC
OE
A
10
CE/PGM
O
7
O
6
A
6
A
5
A
4
A
3
A
2
A
1
A
0
NC
O
0
A
7
A
1
V
P
N
V
C
A
1
A
1
O
1
O
2
NC
O
3
O
4
O
5
G
1
4 3
2
32 31 30
29
28
27
26
25
24
23
22
21
5
6
7
8
9
10
11
12
13
14 15 16 17 18 19 20
TOP VIEW
Chip Carrier
CERDIP
PIN CONFIGURATION
4-17
MILITARY HIGH SPEED 32K x 8 CMOS EPROM
KEY FEATURES
Fast Access Time
— 55 ns
Low Power Consumption
DESC SMD No. 5962-86063
EPI Processing
— Latch-up Immunity Up to 200 mA
Standard EPROM Pinout
GENERAL DESCRIPTION
The WS57C256F is a High Performance 256K UV Erasable Electrically Programmable Read Only Memory. It is
manufactured using an advanced CMOS process technology enabling it to operate at speeds as fast as 55 ns
Access Time.
Two major features of the WS57C256F are its Low Power and High Speed. While operating in a TTL environment it
consumes less than 120 mA while cycling at full speed. Additionally, the WS57C256F can be placed in a standby
mode which drops operating current below 5 mA in a TTL environment and 500 μA in a CMOS environment.
The WS57C256F also has exceptional output drive capability. It can source 4 mA and sink 16 mA per output.
The WS57C256F is configured in the standard EPROM pinout which provides an easy upgrade path for systems
which are currently using standard EPROMs.
PINS
CE/
PGM
OE
A9
A0
VPP
VCCOUTPUTS
MODE
Read
VIL
VIL
X
X
VCCVCC
DOUT
Output
Disable
X
VIH
X
X
VCCVCC
High Z
Standby
VIH
X
X
X
VCCVCC
VPP
2
VCC
High Z
Program
VIL
VIH
X
X
DIN
Program
Verify
X
VIL
X
X
VPP
2
VCC
DOUT
Program
Inhibit
VIH
VIH
X
X
VPP
2
VCC
High Z
Signature
3
VIL
VIL
VH
2
VH
2
VIH
VIL
VCCVCC
23 H
4
VIL
VIL
VCCVCC
EO H
5
MODE SELECTION
NOTES:
1. X can be V
IL
or V
IH
.
2. V
IH
= V
PP
= 12.75 ± 0.25 V.
3. A1 – A8, A10 – A14 = V
IL
.
4. Manufacturer Signature.
5. Device Signature.
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