M27C256B-45F6

Specifications >M27C256B 256 Kbit (32b x 8)UV EPROM

>Brand:ST

>D/C:10+ original

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Datasheets	M27C256B
Product Photos	M27C256B-45F6
Standard Package	13
Category	Integrated Circuits (ICs)
Family	Memory
Series	-
Format - Memory	EPROMs
Memory Type	UV EPROM
Memory Size	256K (32K x 8)
Speed	45ns
Interface	Parallel
Voltage - Supply	4.5 V ~ 5.5 V
Operating Temperature	-40°C ~ 85°C
Package / Case	28-CDIP (0.600", 15.24mm) Window
Packaging	Tube
Supplier Device Package	28-CDIP Frit Seal with Window
Catalog Page	964 (CN081 PDF)

Feature summary
5V ± 10% SUPPLY VOLTAGE in READ
OPERATION
ACCESS TIME: 45ns
LOW POWER CONSUMPTION:
– Active Current 35mA at 5MHz
– Standby Current 100μA
PROGRAMMING VOLTAGE: 12.75V ± 0.25V
PROGRAMMING TIME: 50μs/word
ELECTRONIC SIGNATURE
– Manufacturer Code: 20h
– Device Code: 42h Summary 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 microprocessor systems and is organized as 32,768 by 8 bits.Device operation
The operating modes of the M27C256 are listed in the Operating Modes table. A single
power supply is required in the read mode. All inputs are TTL levels except for VPP and 12V
on A9 for Electronic Signature. Programming
When delivered (and after each erasure for UV EPROM), all bits of the M27C256 are in the
'1' state. Data is introduced by selectively programming '0's into the desired bit locations.
Although only '0's will be programmed, both '1's and '0's can be present in the data word.
The only way to change a '0' to a '1' is by die exposure to ultraviolet light (UV EPROM). The
M27C801 is in the programming mode when VPP input is at 12.75V, G is at VIH and E is
pulsed to VIL. The data to be programmed is applied to 8 bits in parallel to the data output
pins. The levels required for the address and data inputs are TTL. VCC is specified to be
6.25V ± 0.25V. Maximum rating
Stressing the device above the rating listed in the Absolute Maximum Ratings table may
cause permanent damage to the device. These are stress ratings only and operation of the
device at these or any other conditions above those indicated in the Operating sections of
this specification is not implied. Exposure to Absolute Maximum Rating conditions for
extended periods may affect device reliability. Refer also to the STMicroelectronics SURE
Program and other relevant quality documents. ....