ST MICROELECTRONICS 27C256-100 Datasheet

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Page 1

256 Kbit (32Kb × 8) UV EPROM and OTP EPROM

Feature summary

■ 5V ± 10% supply voltage in Read operation

■ Access time: 45ns

■ Low power consumption:

– Active Current 30mA at 5MHz – Standby Current 100µA

■ Programming voltage: 12.75V ± 0.25V

■ Programming time: 100µs/Word

■ Electronic signature

– Manufacturer Code: 20h – Device Code: 8Dh

■ ECOPACK® packages available

M27C256B

FDIP28W (F)

PDIP28 (B)

PLCC32 (C)

May 2006 Rev 2 1/24

www.st.com

Page 2

Contents M27C256B

Contents

1 Summary description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 Device operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.1 Read mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.2 Standby mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.3 Two-line output control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.4 System considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.5 Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.6 PRESTO II programming algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.7 Program inhibit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.8 Program Verify . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.9 Electronic signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.10 Erasure operation (applies for UV EPROM) . . . . . . . . . . . . . . . . . . . . . . . 11

3 Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4 DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5 Package mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

6 Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

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M27C256B List of tables

List of tables

Table 1. Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Table 2. Operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 3. Electronic signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 4. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Table 5. AC measurement conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Table 6. Capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Table 7. Read mode DC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Table 8. Programming mode DC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Table 9. Read mode AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 10. Read mode AC characteristics 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 11. Programming mode AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Table 12. FDIP28WB - 28 pin Ceramic Frit-seal DIP, with window (round 0.280"),

package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Table 13. PDIP28 - 28 pin Plastic DIP, 600 mils width, package mechanical data . . . . . . . . . . . . . . 20

Table 14. PLCC32 - 32 pin Rectangular Plastic Leaded Chip Carrier, package

mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Table 15. Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Table 16. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

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List of figures M27C256B

List of figures

Figure 1. Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 2. DIP connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3. LCC connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 4. Programming flowchart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 5. AC testing input output waveform. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 6. AC testing load circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 7. Read mode AC waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 8. Programming and Verify modes AC waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Figure 9. FDIP28WB - 28 pin Ceramic Frit-seal DIP, with window, package outline. . . . . . . . . . . . . 19

Figure 10. PDIP28 - 28 pin Plastic DIP, 600 mils width, package outline . . . . . . . . . . . . . . . . . . . . . . 20

Figure 11. PLCC32 - 32 pin Rectangular Plastic Leaded Chip Carrier, package outline. . . . . . . . . . . 21

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M27C256B Summary description

1 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.

The FDIP28W (window ceramic frit-seal package) has a transparent lid which allows the

user to expose the chip to ultra viol et light to er ase the bit pattern. A ne w 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 and PLCC32 packages.

In order to meet environmental requirements, ST offers the M27C256B 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

A0-A14 Q0-Q7

M27C256B

AI00755B

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Summary description M27C256B

Table 1. Signal names

A0-A14 Address Inputs Q0-Q7 Data Outputs E

Chip Enable G V

Output Enable

Program Supply

Supply Voltage

Ground NC Not Connected Internally DU Don’t Use

Figure 2. DIP connections

A12

Q2 SS

A7 A6 A5 A4 A3 A2 A1 A0

2 3 4 5 6 7

M27C256B

8 9 10 11 12 13 14

28 27 26 25 24 23 22 21 20 19 18 17 16 15

AI00756

A14 A13 A8 A9 A11 G A10 E Q7 Q6 Q5Q1 Q4 Q3V

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M27C256B Summary description

Figure 3. LCC connections

A13

A14

A8 A9 A11 NC G

A10 E Q7 Q6

A6 A5 A4 A3 A2 A1 A0

A12

M27C256B

AI00757

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Device operation M27C256B

2 Device operation

The operating modes of the M27C256B are listed in the Operating Modes. A single power supply is required in the read mode. All inputs are TTL lev els except for V for Electronic Signature.

2.1 Read mode

The M27C256B has two control functions, both of which must be logically active in order to obtain data at the outputs. Chip Enable (E device selection. Out put Enable (G the output pins, independent of device selection. Assuming that the addresses are stable, the address access time (t available at the output after delay of t been low and the addresses have been stable for at least t

2.2 Standby mode

The M27C256B has a standby mode which reduces the supply current from 30mA to 100µA. The M27C256B is placed in the standb y mode by applying a CMOS high signal to the E

input. When in the standby mode, t he outputs are in a high impedance state,

independent of the G

input.

) is the power control and should be u sed for

) is the output control and should be used to gate data to

) is equal to the delay from E to output (t

AVQV

from the falling edge of G, assuming that E has

GLQV

AVQV-tGLQV

and 12V on A9

). Data is

ELQV

2.3 Two-line output control

Because EPROMs are usually used in larger memory arrays, this product features a 2 line control function which accommodates the use of multiple memory connection. The two line control function allows:

● the lowest possible memory power dissipation,

● complete assurance that output bus contention will not occur.

For the most efficient use of these two control lines, E primary device selecting function, while G devices in the array and connected to the READ ensures that all deselected memory devices are in their low power standby mode and that the output pins are only active when data is desired from a particular memory device.

should be decoded and used as the

should be made a common connection to all

line from the system control bus. This

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M27C256B Device operation

2.4 System considerations

The power switch ing characteristics of Adv ance CMOS EPROMs r equire careful decoupling of the devices. The supply cu rrent, I

, has three segments that are of interest to the system

designer: the standby current level, the active current level, and transient current peaks th at are produced by the falling and rising edges of E

. The magnitude of this transient current peaks is dependent on the capacitive and inductive loading of the device at the output. The associated transient voltage p eaks can be suppressed b y complying with the two line outp ut control and by properly selected decoupling capacitors. It is recommended that a 0.1µF ceramic capacitor be used on every device between V

and VSS. This should be a high

frequency capacitor of low inherent indu cta nce and sho uld b e placed a s clo se to the d evice as possible. In addition, a 4.7µF bulk electrolytic capacitor should be used between V V

for e very eight devices. The bulk capacitor should be located near the power supply

and

connection point. The purpose of the bulk capacitor is t o o vercome the voltage drop caused by the inductive effects of PCB traces.

2.5 Programming

When delivered (and after each erasure for UV EPROM), all bits of the M27C256B 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 M27C256B is in the programming mode when V pulsed to V

. 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. V

6.25V ± 0.25 V.

input is at 12.75V, G is at VIH and E is

is specified to be

2.6 PRESTO II programming algorithm

PRESTO II Programming Algorithm allows to program the whole array with a guaranteed margin, in a typical time of 3.5 seconds. Programming with PRESTO II involves the application of a sequence of 100µs program pulses to each b yte un til a correct verify occurs (see Figure 4.). During programming and verify operation, a MARGIN MODE circuit is automatically activated in order to guarantee that each cell is programmed with enough margin. No overprogram pulse is applied since the verify in MARGIN MODE provides necessary margin to each programmed cell.

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Device operation M27C256B

Figure 4. Programming flowchart

VCC = 6.25V, VPP = 12.75V

n = 0

E = 100µs Pulse

VERIFY

YES

Last

Addr

YES

CHECK ALL BYTES

1st: VCC = 6V

2nd: VCC = 4.2V

++ Addr

AI00760B

YES

++n

= 25

FAIL

2.7 Program inhibit

Programming of multiple M27C256Bs in parallel with different data is also easily accomplished. Except for E

, all like inputs including G of the parallel M27C256B may be common. A TTL low level pulse applied to a M27C256B's E program that M27C256B. A high level E programmed.

2.8 Program Verify

A verify (read) should be performed on the programmed bits to determine that they were correctly programmed. The v erify is accomplished with G V

at 6.25V.

2.9 Electronic signature

The Electronic Signature (ES) mode allows the reading out of a binary code from an EPROM that will identify its manufacturer and type. This mode is intended for use by programming equipment to automatically match the device to be programmed with its corresponding programming algorithm. The ES mode is functional in the 25°C ± 5°C ambient temperature range t hat is required when programming the M27C256B. To activate the ES mode, the progr amm ing e qui pme nt must force 11.5V to 12.5V on address line A9 of the M27C256B, with V device outputs by toggling address line A0 from V held at V

during Electronic Signature mode. Byte 0 (A0 = VIL) represents the manufacturer

code and byte 1 (A0 = V M27C256B, these two ident ifier bytes are given in Table 3 and can be read-out on outputs Q7 to Q0.

= VPP = 5V. Two identifier bytes may then be sequenced from the

) the device identifier code. For the STMicroelectronics

input, with VPP at 12.75V, will

input inhibits the other M27C256Bs from being

at VIL, E at VIH, VPP at 12.75V and

to VIH. All other address lines must be

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M27C256B Device operation

2.10 Erasure operation (applies for UV EPROM)

The erasure characteristics of the M27C256B is such that erasu re begins when the cells are exposed to light with wavelengths shorter than approximately 4000 Å. It should be noted that sunlight and some type of fluorescent lamps have wavelengths in the 3000-4000 Å range. Research shows that constant exposure to room level fluorescent lighting could erase a typical M27C256B in about 3 years, while it would take approximately 1 week to cause erasure when exposed to direct sunlight. If the M27C256B is to be exposed to these types of lighting conditions for extended periods of time, it is suggeste d that opaque labels be put over the M27C256B window to prevent unintentional erasure. The recommended erasure procedure for the M27C256B is exposure to short wave ultraviolet light which has wavelength 2537Å. The integrated dose (i.e. UV intensity x exposure time) for erasure should be a minimum of 15 W-sec/cm 15 to 20 minutes using an ultr a violet lamp with 12 000 µW/cm should be placed within 2.5 cm (1 inch) of the lamp tubes during the erasure. Some lamps have a filter on their tubes which should be removed before erasure.

Table 2. Operating modes

(1)

. The erasure time with this dosage is approximately

power rating. The M27C25 6B

Mode E G A9 V

Read V Output Disable V Program V Verify V Program Inhibit V Standby V Electronic Signature V

1. X = V

Table 3. Electronic signature

or VIL, VID = 12V ± 0.5V.

IL IL

Pulse V

IH IH IH

IH IH

XVCCData Out XVCCHi-Z XVPPData In XVPPData Out XVPPHi-Z

XXVCCHi-Z

Identifier A0 Q7 Q6 Q5 Q4 Q3 Q2 Q1 Q0 Hex Data

Manufacturer’s Code

Device Code V

00100000 20h

100011018Dh

Q7-Q0

Codes

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Page 12

Maximum rating M27C256B

3 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 ot her conditions above those indicated in the Operating sections of this specification is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may aff ect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality documents.

Table 4. Absolute maximum ratings

Symbol Parameter Value Unit

BIAS

STG

1. Depends on range.

2. Minimum DC voltage on Input or Output is –0.5V with possible undershoot to –2.0V for a period less than

20ns. Maximum DC voltage on Output is V than 20ns.

Ambient Operating Temperature Temperature Under Bias –50 to 125 °C Storage Temperature –65 to 150 °C

(2)

Input or Output Voltage (except A9) –2 to 7 V Supply Voltage –2 to 7 V

(2)

A9 Voltage –2 to 13.5 V Program Supply Voltage –2 to 14 V

(1)

+0.5V with possible overshoot to VCC +2V for a period less

–40 to 125 °C

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M27C256B DC and AC parameters

4 DC and AC parameters

This section summarizes the operating and measurement conditions, and the DC and AC characteristics of the device. The parameters in the DC and AC Characteristic tables that follow are derived from tests performed under the Measurement Conditions summarized in the relevant tables. Designers should check that the operating conditions in their circuit match the measurement conditions when relying on the quoted parameters.

Table 5. AC measurement conditions

High Speed Standard

Input Rise and Fall Times ≤ 10ns ≤ 20ns Input Pulse Voltages 0 to 3V 0.4V to 2.4V Input and Output Timing Ref.

Voltages

1.5V 0.8V and 2V

Figure 5. AC testing input output waveform

High Speed

Standard

2.4V

0.4V

1.5V

2.0V

0.8V

AI01822

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DC and AC parameters M27C256B

Figure 6. AC testing load circuit

1.3V

1N914

3.3kΩ

DEVICE UNDER

TEST

CL = 30pF for High Speed CL = 100pF for Standard CL includes JIG capacitance

OUT

AI01823B

Table 6. Capacitance

(1) (2)

Symbol Parameter Test Condition Min Max Unit

OUT

1. Sampled only, not 100% tested.

2. (T

Table 7. Read mode DC characteristics

Input Capacitance VIN = 0V 6 pF

Output Capacitance V

= 25 °C, f = 1 MHz)

(1) (2)

= 0V 12 pF

OUT

Symbol Parameter Test Condition Min Max Unit

CC1

CC2

Input Leakage Current 0V ≤ VIN ≤ V

Output Leakage Current 0V ≤ V

= VIL, G = VIL,

Supply Current

= 0mA, f = 5MHz

OUT

Supply Current (Standby) TTL E = V Supply Current (Standby)

CMOS

> VCC – 0.2V 100 µA

Program Current VPP = V Input Low Voltage –0.3 0.8 V

(3)

Input High Voltage 2 VCC + 1 V Output Low Voltage IOL = 2.1mA 0.4 V

OUT

≤ V

±10 µA ±10 µA

30 mA

1mA

100 µA

Output High Voltage TTL IOH = –1mA 3.6 V

Output High Voltage CMOS I

1. T

= 0 to 70°C, –40 to 85°C, –40 to 105°C or –40 to 125°C; VCC = 5V ± 5% or 5V ± 10%; VPP = VCC.

must be applied simultaneously with or before VPP and removed simultaneously or after VPP.

2. V

3. Maximum DC voltage on Output is VCC +0.5V.

= –100µA VCC – 0.7V V

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Page 15

M27C256B DC and AC parameters

Table 8. Programming mode DC characteristics

(1) (2)

Symbol Parameter Test Condition Min Max Unit

1. T

2. V

A CC

Input Leakage Current VIL ≤ VIN ≤ V

±10 µA Supply Current 50 mA Program Current E = V Input Low Voltage –0.3 0.8 V

Input High Voltage 2 VCC + 0.5 V

50 mA

Output Low Voltage IOL = 2.1mA 0.4 V Output High Voltage TTL IOH = –1mA 3.6 V A9 Voltage 11.5 12.5 V

= 25 °C; VCC = 6.25V ± 0.25V; VPP = 12.75V ± 0.25V.

must be applied simultaneously with or before VPP and removed simultaneously or after VPP.

15/24

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DC and AC parameters M27C256B

Figure 7. Read mode AC waveforms

tAVQV

tELQV

VALID

tGLQV

Test

Condition

E = VIL,

G = V

= V

A0-A14

Q0-Q7

)

Table 9. Read mode AC characteristics

Symbol Alt Parameter

AVQVtACC

ELQVtCE

GLQVtOE

Address Valid to Output Valid

Chip Enable Low to Output Valid

Output Enable Low to Output Valid

VALID

tAXQX

tEHQZ

tGHQZ

AI00758B

(1) (2)

M27C256B

(3)

-60 -70 -80

Min Max Min Max Min Max Min Max

45 60 70 80 ns

25 30 35 40 ns

Hi-Z

Unit-45

(4)

EHQZ

(4)

GHQZ

AXQXtOH

= 0 to 70°C, –40 to 85°C, –40 to 105°C or –40 to 125°C; VCC = 5V ± 5% or 5V ± 10%; VPP = V

1. T

2. VCC must be applied simultaneously with or before VPP and removed simultaneously or after VPP.

3. Speed obtained with High Speed AC measurement conditions.

4. Sampled only, not 100% tested.

Chip Enable High

to Output Hi-Z Output Enable

High to Output Hi-Z Address Transition

to Output Transition

= V

= VIL,

= V

025030030030ns

0000ns

16/24

Page 17

M27C256B DC and AC parameters

)

Table 10. Read mode AC characteristics 2

(1) (2)

M27C256B

Symbol Alt Parameter

Test

Condition

Min Max Min Max Min Max Min Max

AVQVtACC

ELQVtCE

Address Valid to Output Valid

Chip Enable Low to Output Valid

E = VIL,

G = V

= V

90 100 120 150 ns

Output Enable

GLQVtOE

Low to Output

E = V

40 50 60 65 ns

Valid

EHQZ

GHQZ

(3)

Chip Enable High

to Output Hi-Z Output Enable

High to Output

= V

E = V

0 30 0 30 0 40 0 50 ns

Hi-Z Address

AXQXtOH

Transition to Output Transition

= 0 to 70°C, –40 to 85°C, –40 to 105°C or –40 to 125°C; VCC = 5V ± 5% or 5V ± 10%; VPP = V

1. T

2. VCC must be applied simultaneously with or before VPP and removed simultaneously or after VPP.

3. Sampled only, not 100% tested.

= VIL,

G = V

0000 ns

Unit-90 -10 -12 -15/-20/-25

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Page 18

DC and AC parameters M27C256B

Figure 8. Programming and Verify modes AC waveforms

A0-A14

tAVEL

Q0-Q7

Table 11. Programming mode AC characteristics

DATA IN DATA OUT

tQVEL

tVPHEL

tVCHEL

tELEH

PROGRAM VERIFY

Symbol Alt Parameter

AVEL

QVEL

VPHELtVPSVPP

VCHELtVCSVCC

ELEH

EHQX

QXGLtOES

GLQV

GHQZtDFP

GHAX

1. T

= 25 °C; VCC = 6.25V ± 0.25V; VPP = 12.75V ± 0.25V.

must be applied simultaneously with or before VPP and removed simultaneously or after VPP.

2. V

Address Valid to Chip Enable Low 2 µs

Input Valid to Chip Enable Low 2 µs

High to Chip Enable Low 2 µs

Chip Enable Program Pulse Width 95 105 µs

Chip Enable High to Input Transition 2 µs

Input Transition to Output Enable Low 2 µs

Output Enable Low to Output Valid 100 ns

Output Enable High to Output Hi-Z 0 130 ns

Output Enable High to Address Transition 0 ns

VALID

tEHQX

tGLQV

tQXGL

(1) (2)

Test

Condition

tGHQZ

tGHAX

AI00759

Min Max Unit

18/24

Page 19

M27C256B Package mechanical

5 Package mechanical

Figure 9. FDIP28WB - 28 pin Ceramic Frit-seal DIP, with window, package outline

B1 B

1. Drawing is not to scale.

Table 12. FDIP28WB - 28 pin Ceramic Frit-seal DIP, with window (round 0.280"),

A1AL e

E1 E

∅

eA eB

FDIPW-a

package mechanical data

millimeters inches

Symbol

Typ Min Max Typ Min Max

A 5.72 0.225 A1 0.51 1.40 0.020 0.055 A2 3.91 4.57 0.154 0.180 A3 3.89 4.50 0.153 0.177

B 0.41 0.56 0.016 0.022 B1 1.45 – – 0.057 – –

C 0.23 0.30 0.009 0.012 D 36.50 37.34 1.437 1.470

D2 33.02 – – 1.300 – –

E 15.24 – – 0.600 – – E1 13.06 13.36 0.514 0.526

e2.54– –0.100– – eA 14.99 – – 0.590 – – eB 16.18 18.03 0.637 0.710

L 3.18 4.10 0.125 0.161

S 1.52 2.49 0.060 0.098

∅ 7.11 – – 0.280 – –

α 4° 11° 4° 11°

N28 28

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Page 20

Package mechanical M27C256B

Figure 10. PDIP28 - 28 pin Plastic DIP, 600 mils width, package outline

A1AL

B1 B e1

E1 E

1. Drawing is not to scale.

Table 13. PDIP28 - 28 pi n Plastic DIP, 600 mils width, package mechanical data

eA eB

PDIP

millimeters inches

Symbol

Typ Min Max Typ Min Max

A 4.445 0.1750 A1 0.630 0.0248 A2 3.810 3.050 4.570 0.1500 0.1201 0.1799

B 0.450 0.0177 B1 1.270 0.0500

C 0.230 0.310 0.0091 0.0122 D 36.830 36.580 37.080 1.4500 1.4402 1.4598

D2 33.020 – – 1.3000 – –

E 15.240 0.6000 E1 13.720 12.700 14.480 0.5402 0.5000 0.5701 e1 2.540 – – 0.1000 – – eA 15.000 14.800 15.200 0.5906 0.5827 0.5984 eB 15.200 16.680 0.5984 0.6567

L 3.300 0.1299

S 1.78 2.08 0.070 0.082

α 0° 10° 0° 10°

N28 28

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Page 21

M27C256B Package mechanical

Figure 11. PLCC32 - 32 pin Rectangular Plastic Leaded Chip Carrier, package

outline

A1 A2

1 N

D2 D2

1. Drawing is not to scale.

Table 14. PLCC32 - 32 pin Rectangular Plastic Leaded Chip Carrier, package

E1 E

0.51 (.020)

1.14 (.045)

PLCC-A

mechanical data

millimeters inches

Symbol

Typ Min Max Typ Min Max

A 3.17 3.56 0.125 0.140 A1 1.53 2.41 0.060 0.095 A2 0.38 – 0.015 –

B 0.33 0.53 0.013 0.021 B1 0.66 0.81 0.026 0.032

CP 0.10 0.004

D 12.32 12.57 0.485 0.495 D1 11.35 11.51 0.447 0.453 D2 4.78 5.66 0.188 0.223 D3 7.62 – – 0.300 – –

E 14.86 15.11 0.585 0.595 E1 13.89 14.05 0.547 0.553 E2 6.05 6.93 0.238 0.273 E310.16– –0.400– –

e1.27– –0.050– –

F 0.00 0.13 0.000 0.005

R0.89– –0.035– – N32 32

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Page 22

Part numbering M27C256B

6 Part numbering

Table 15. Ordering information scheme

Example: M27C256B -70 X C 1 TR

Device Type

M27

Supply Voltage

C = 5V

Device Function

256B = 256 Kbit (32Kb x 8)

Speed

(1)

= 45 ns

-45

-60 = 60 ns

-70 = 70 ns

-80 = 80 ns

-90 = 90 ns

-10 = 100 ns

-12 = 120 ns

-15 = 150 ns

-20 = 200 ns

-25 = 250 ns

Tolerance

blank = ± 10% X = ± 5%

Package

F = FDIP28W B = PDIP28 C = PLCC32

Temperature Range

1 = 0 to 70 °C 3 = –40 to 125 °C 6 = –40 to 85 °C

Options

TR = Tape & Reel Packing

1. High Speed, see AC Characteristics section for further information.

For a list of available options (Speed, Package, etc) or for further information on any aspect of this device, please contact the STMicroelectronics Sales Office nearest to you.

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Page 23

M27C256B Revision history

7 Revision history

Table 16. Document revision history

Date Version Revision Details

July 1998 1.0 First Issue 20-Sep-2000 1.1 AN620 Reference removed 29-Nov-2000 1.2 PLCC codification changed (Table 15.) 02-Apr-2001 1.3 FDIP28W mechanical dimensions changed (Table 12.)

29-Aug-2002 1.4

18-May-2006 2

Package mechanical data clarified for PDIP28 (Table 13.), PLCC32 (Table 14., Figure 11.) and TSOP28 (Table 15., Figure 13.)

Document converted to new template (sections added, information moved). TSOP28 package removed. Packages are ECOPACK® compliant. X option removed from Table 15: Ordering information scheme.

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Page 24

M27C256B

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