M87C257
Address Latched
256 Kbit (32Kb x8) UV EPROM and OTP EPROM
Feature summary
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5V ± 10% supply voltage in Read operation
Integrated address latch
Access time: 45ns
Low power consumption:
– Active Current 30mA
– Standby Current 100µA
Programming voltage: 12.75V ± 0.25V
Programming times of around 3s
Electronic signature
– Manufacturer Code: 20h
– Device Code: 80h
ECOPACK® packages available
28
1
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FDIP28W (F)
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PLCC32 (C)
May 2006
Rev 2
1/9
www.st.com
1
Contents
M87C257
Contents
1
2
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Device operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
Read mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Standby mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Two Line Output Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
System considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
PRESTO II programming algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Program Inhibit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Program Verify . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Electronic signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Erasure operation (applies for UV EPROM) . . . . . . . . . . . . . . . . . . . . . . . 10
3
4
5
6
7
Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Package mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
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M87C257
List of tables
List of tables
Table 1.
Table 2.
Table 3.
Table 4.
Table 5.
Table 6.
Table 7.
Table 8.
Table 9.
Table 10.
Table 11.
Table 12.
Table 13.
Table 14.
Table 15.
Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Electronic signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
AC measurement conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Read mode DC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Programming mode DC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Read mode AC characteristics 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Read mode AC characteristics 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Programming mode AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
FDIP28WB - 28 pin Ceramic Frit-seal DIP, with window (round 0.280"),
package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
PLCC32 - 32 pin Rectangular Plastic Leaded Chip Carrier,
package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
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3/22
List of figures
M87C257
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
DIP connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
LCC connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Programming flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
AC testing input output waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
AC testing load circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Read mode AC waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Programming and Verify modes AC waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
FDIP28W - 28 pin Ceramic Frit-seal DIP, with window, package outline . . . . . . . . . . . . . . 18
PLCC32 - 32 pin Rectangular Plastic Leaded Chip Carrier, package outline. . . . . . . . . . . 19
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M87C257
Description
1
Description
The M87C257 is a 256 Kbit EPROM offered in the two ranges UV (ultra violet erase) and
OTP (one time programmable). It incorporates latches for all address inputs to minimize chip
count, reduce cost, and simplify the design of multiplexed bus 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 expose the chip to ultraviolet light to erase the bit pattern. 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 M87C257 is offered in PLCC32 package.
In order to meet environmental requirements, ST offers the M87C257 in ECOPACK®
packages.
ECOPACK packages are Lead-free. The category of second Level Interconnect is marked
on the package and on the inner box label, in compliance with JEDEC Standard JESD97.
The maximum ratings related to soldering conditions are also marked on the inner box label.
ECOPACK is an ST trademark. ECOPACK specifications are available at:
www.st.com.
Figure 1.
Logic diagram
VCC
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Q0-Q7
M87C257
VSS
AI00928B
5/22
嵌入式系统
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