M27C256B
256 Kbit (32Kb x 8) UV EPROM and OTP EPROM
s
5V ± 10% SUPPLY VOLTAGE in READ
OPERATION
ACCESS TIME: 45ns
LOW POWER CONSUMPTION:
– Active Current 30mA at 5MHz
– Standby Current 100µA
28
s
s
28
s
s
s
PROGRAMMING VOLTAGE: 12.75V ± 0.25V
PROGRAMMING TIME: 100µs/word
ELECTRONIC SIGNATURE
– Manufacturer Code: 20h
– Device Code: 8Dh
1
1
FDIP28W (F)
PDIP28 (B)
DESCRIPTION
The M27C256B is a 256 Kbit EPROM offered in
the two ranges UV (ultra violet erase) and OTP
(one time programmable). It is ideally suited for mi-
croprocessor systems and is organized as 32,768
by 8 bits.
The FDIP28W (window ceramic frit-seal package)
has a transparent lid which allows the user to ex-
pose the chip to ultraviolet light to erase the bit pat-
tern. A new pattern can then be written to the
device by following the programming procedure.
For applications where the content is programmed
only one time and erasure is not required, the
M27C256B is offered in PDIP28, PLCC32 and
TSOP28 (8 x 13.4 mm) packages.
PLCC32 (C)
TSOP28 (N)
8 x 13.4 mm
Figure 1. Logic Diagram
VCC
VPP
15
A0-A14
8
Q0-Q7
E
G
M27C256B
VSS
AI00755B
August 2002
1/16
STMICROELECTRONICS [ STMICROELECTRONICS ]
