SGS Thomson Microelectronics M27C400 Datasheet

M27C400

4 Mbit (512Kb x8 or 256Kb x16) UV EPROM and OTP EPROM

■ 5V ± 10% SUPPLY VOLTAGE in READ

OPERATION

■ ACCESS TIME: 55ns

■ BYTE-WIDE or WORD-WIDE

CONFIGURABLE

■ 4 Mbit MASK ROM REPLACEMENT

■ LOW POWER CONSUMPTION

– Active Current 70mA at 8MHz
– Stand-by Current 100µA

■ PROGRAMMI NG VOLT AGE: 12.5V ± 0.25V

■ PROGRAMMING TIME: 100µs/word

■ ELECTRONIC SIGNATURE

– Manufacturer Code: 20h
– Device Code: B8h

40

1

FDIP40W (F) PDIP40 (B)

Figure 1. Logic Diagram

40

1

DESCRIPTION

The M27C400 is a n 4 Mbit EPROM of fe red i n the
two ranges UV (ultra violet erase) and OTP (one
time programmable). It is ideally suited for micro­processor syst ems requiring large data or program
storage. It is organised as either 512 Kwords of 8
bit or 256 Kwords of 16 bit. The pin-out is compat­ible with the most common 8 Mbit Mask ROM.

The FDIP40W (window ceramic frit-seal package)
has a transparent lid which all ows the user to ex­pose the chip to ultraviolet light to erase the bit pat­tern.

A new pattern can then be written rapidly to the de­vice by following the programming procedure.

For applications where the content is programmed
only one time and erasure is not required, the
M27C400 is offered in PDIP40 package.

A0-A17

BYTEV

PP

V

CC

18

E

G

M27C400

V

SS

Q15A–1

15

Q0-Q14

AI01634

1/14May 1999

M27C400

Figure 2. DIP C on ne ctions

A17 A8

A7
A6
A5
A4
A3
A2
A1
A0

V

SS

Q0
Q8
Q1
Q9
Q2

Q3

Q11

1
2
3
4
5
6
7
8
9

E

10

M27C400

11

G

12
13
14
15
16
17
18
19

40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
2120

AI01635

A9
A10
A11
A12
A13
A14
A15
A16
BYTEV
V

SS

Q15A–1
Q7
Q14
Q6
Q13
Q5
Q12Q10
Q4
V

CC

PP

DEVICE OPERATION

The operating modes of the M27C400 are listed in
the Operating Modes Table. A single power supply
is required in the read mode. All inputs are TTL
compatib le exce pt for V

and 12V on A9 for the

PP

Electronic Signature.

Read Mode

The M27C400 has two organisations, Word-wide
and Byte-wide. The organisation is selected by the
signal level on the BYTE

VPP pin. When BYTEV

PP

is at VIH the Word-wide organisation is selected

and the Q15A–1 pin is used for Q15 Data Output.
When the BYTE

VPP pin is at VIL the Byte-wide or­ganisation is selected and the Q15A–1 pin is used
for the Address Input A–1. When the memory is

Table 1. Signal Names

A0-A17 Address Inputs

Q0-Q7 Data Outputs
Q8-Q14 Data Outputs

Q15A–1 Data Output / Address Input

E
G

BYTE

V

CC

V

SS

V

PP

Chip Enable
Output Enable

Byte Mode / Program Supply

Supply Voltage

Ground

logically regarded as 16 bit wid e, but read in the
Byte-wide organisation, then with A–1 at V

IL

the
lower 8 bits of the 16 bit data are selected and with
A–1 at V

the upper 8 bits of the 16 bit dat a are

IH

sele cte d.
The M27C400 has two cont rol functions, both of

which must be logically ac tive in order to obtain
data at the outputs. In addition the Word-wide or
Byte- wide organisation must be selected.

Chip Enable (E
used for device selection. Output Enable (G

) is the power control and should be

) is the
output control and should be used to gate data to
the output pins i ndependent of device selection.
Assuming that the addresses are s table, the ad­dress access time (t
from E

to output (t

ELQV

output after a delay of t

, assuming that E has been low and the ad-

of G
dresses have been stable for at least t

) is equal to the delay

AVQV

). Data is available at the

from the falling e dge

GLQV

AVQV-tGLQV

Standby Mode

The M27C400 has a standby mode which reduces
the supply current from 50mA to 100µA. The
M27C400 is placed in the standby mode by apply­ing a CMOS high signal to the E

input. When in the
standby mode, the outputs are in a high imped­ance state, independent of the G

input.

.

2/14

M27C400

Table 2. Absolute Maximum Ratings

(1)

Symbol Parameter Value Unit

T

A

T

BIAS

T

STG

(2)

V

IO

V

CC

(2)

V

A9

V

PP

Note: 1. Except for the rating “Oper at i ng Temperature Ra nge”, stresses above those li sted in t he Table “A bsolute Maximum Ratings” m ay

cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions
above those indi cated in t he Operating sect i ons of thi s specif i cation is not imp l i ed. Exposu re to Absolute Ma xim um Rati ng condi ­tions for extended per iods may aff ect device reliabilit y. Refer also to the STMicroel ectronics SURE Program an d other relevan t qual ­ity docum en ts .

2. Minimum DC vo ltage on Inpu t or Out put is – 0.5V w ith po ssible un dersh oot to –2.0V fo r a pe riod les s than 20ns. Ma ximu m DC
voltage on Output is V

3. Depends on range.

Ambient Operating Temperature

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

Input or Output Voltage (except A9) –2 to 7 V
Supply Voltage –2 to 7 V
A9 Voltage –2 to 13.5 V
Program Supply Voltage –2 to 14 V

+0.5V with possible overshoot to VCC +2V for a period l ess than 20ns.

CC

(3)

–40 to 125 °C

Table 3. Operating Modes

Mode E

Read Word-wide
Read Byte-wide Upper
Read Byte-wide Lower
Output Disable
Program

V

IL

Verify
Program Inhibit
Standby
Electronic Signature

Note: X = VIH or VIL, VID = 12V ± 0.5V.

V

IL

V

IL

V

IL

V

IL

Pulse V
V

IH

V

IH

V

IH

V

IL

V
V
V
V

V
V

V

BYTEV

G

IL

IL

IL

IH

IH

IL

IH

V

IH

V

IL

V

IL

X X Hi-Z Hi-Z Hi-Z

V

PP

V

PP

V

PP

A9 Q7-Q0 Q14-Q8 Q15A–1

PP

X Data Out Data Out Data Out
X Data Out Hi-Z
X Data Out Hi-Z

X Data In Data In Data In
X Data Out Data Out Data Out
X Hi-Z Hi-Z Hi-Z

V

IH

V

IL

X X X Hi-Z Hi-Z Hi-Z

IL

V

IH

V

ID

Codes Codes Code

Table 4. Electronic Signature

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

Manufacturer’s Code
Device Code

Note: O ut puts Q15-Q8 ar e set to '0'.

V

IL

V

IH

00100000 20h
10110010 B2h

3/14

M27C400

Table 5. AC Measurement Conditions

High Speed Standard

Input Rise and Fall Times
Input Pulse Voltages 0 to 3V 0.4V to 2.4V
Input and Output Timing Ref. Voltages 1.5V 0.8V and 2V

10ns

≤

20ns

≤

Figure 3. Tes ting Inp ut Output Wav ef orm

High Speed

3V

1.5V

0V

Standard

2.4V

0.4V

Table 6. Capacitance

(1)

(TA = 25 °C, f = 1 MHz)

2.0V

0.8V

AI01822

Figure 4. AC Testing Load Circuit

1.3V

1N914

3.3kΩ

DEVICE

UNDER

TEST

CL

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

OUT

Symbol Parameter Test Condition Min Max Unit

C

Input Capacitance (except BYTEVPP)V

IN

C

OUT

Note: 1. Sampled only, not 100% tested.

Input Capacitance (BYTE
Output Capacitance

VPP)V

V

IN

IN

OUT

= 0V
= 0V

= 0V

10 pF

120 pF

12 pF

AI01823B

Two Line Outp ut C ontrol

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:

a. the lowest possible memory power dissipation
b. complete assurance that output bus contention

will not occur.

4/14

For the most efficient use of these two control
lines, E
ry device selecting function, while G

should be decoded and used as the prima-

should be
made a common connectio n to all devices in the
array and connected to the READ

line from the
system control bus. This ensures that all deselect­ed memory devices are in their low power standby
mode and that the output pins are only active
when data is required from a particular memory
device.

M27C400

Table 7. Read Mode DC Characteristics

(1)

(TA = 0 to 70 °C or –40 to 85 °C; VCC = 5V ± 5% or 5V ± 10%; VPP = VCC)

Symbol Parameter Test Condition Min Max Unit

I

I

I

CC

I

CC1

I

CC2

I
V

V

IH

V

V

Note: 1. VCC must be ap pl i e d simultaneously with or before VPP and removed simultaneously or af t e r VPP.

Input Leakage Current

LI

Output Leakage Curren t

LO

Supply Current

Supply Current (Standby) TTL
Supply Current (Standby) CMOS
Program Current

PP

Input Low Voltage –0.3 0.8 V

IL

(2)

Input High Voltage 2
Output Low Voltage

OL

Output High Voltage TTL

OH

2. Maximu m DC voltage on Output is V

CC

+0.5 V.

I

I

0V

0V ≤ V

E

OUT

E

OUT

E

≤ V

V

≤

IN

OUT

= VIL, G = VIL,

= 0mA, f = 8MHz

= VIL, G = VIL,

= 0mA, f = 5MHz

E

= V

> VCC – 0.2V

V

= V

PP

I

= 2.1mA

OL

I

= –400µA

OH

≤ V

IH

CC

CC

CC

±1 µA

±10 µA

70 mA

50 mA

1mA

100 µA

10 µA

V

+ 1

CC

0.4 V

2.4 V

V

System Considerations

The power switching characteristics of Advanced
CMOS EPROMs require careful decoupling of the
supplies to the devices. The supply current I

CC

has three segments of importance to the system
designer: the standby current, the active current
and the transient peaks that are produc ed by the
falling and rising edges of E

. The magnitude of the
transient current peaks is dependent on the ca­pacitive and inductive loadi ng of the device out­puts. The associated transient voltage peaks can
be suppressed by complying with the two line out­put control and by properly selected decoupling

capacitors. It is recommended that a 0.1µF ceram­ic capacitor is used on every device between V

CC

and VSS. This should be a high frequency type of
low inherent inductance and should be placed as
close as possible to the device. In addition, a

4.7µF electrolytic capacitor should be used be­tween V

and VSS for every eight devices. This

CC

capacitor should be mounted near the power sup­ply connection point. The purpose of this capacitor
is to overcome the voltage d r op caus ed by the in­ductiv e effects of PCB traces.

Programming

When delivered (and after each erasure for UV
EPROM), all bits of the M27C400 are in the '1'
state. Data is introduced by selectively program ­ming '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 exposition to ultravio­let light (UVEPROM). The M 27C400 is in the pro­gramming mode when V

and E is p ulse d to VIL. The data to b e pro-

at V

IH

input is at 12.5V, G is

PP

grammed is applied to 16 bits in parallel to the data
output pins. The levels required for the address
and data inputs are TTL. V

is specified to be

CC

6.25V ± 0.25V.

5/14