M27512
NMOS 512 Kbit (64Kb x 8) UV EPROM
NOT FOR NEW DESIGN
s
s
s
s
s
FAST ACCESS TIME: 200ns
EXTENDED TEMPERATURE RANGE
SINGLE 5V SUPPLY VOLTAGE
LOW STANDBY CURRENT: 40mA max
TTL COMPATIBLE DURING READ and
PROGRAM
FAST PROGRAMMING ALGORITHM
ELECTRONIC SIGNATURE
PROGRAMMING VOLTAGE: 12V
1
28
s
s
s
DESCRIPTION
The M27512 is a 524,288 bit UV erasable and
electrically programmable memory EPROM. It is
organized as 65,536 words by 8 bits.
The M27512 is housed in a 28 Pin Window Ce-
ramic Frit-Seal Dual-in-Line package. The trans-
parent lid allows the user to expose the chip to
ultraviolet light to erase the bit pattern. A new pat-
tern can then be written to the device by following
the programming procedure.
FDIP28W (F)
Figure 1. Logic Diagram
VCC
16
A0-A15
8
Q0-Q7
E
GVPP
M27512
VSS
AI00765B
November 2000
This is information on a product still in production but not recommended for new designs.
1/11
M27512
Table 2. Absolute Maximum Ratings
Symbol
T
A
T
BIAS
T
STG
V
IO
V
CC
V
A9
V
PP
Parameter
Ambient Operating Temperature
Temperature Under Bias
Storage Temperature
Input or Output Voltages
Supply Voltage
A9 Voltage
Program Supply
Grade 1
Grade 6
Grade 1
Grade 6
Value
0 to 70
–40 to 85
–10 to 80
–50 to 95
–65 to 125
–0.6 to 6.5
–0.6 to 6.5
–0.6 to 13.5
–0.6 to 14
Unit
°C
°C
°C
V
V
V
V
Note:
Except for the rating "Operating Temperature Range", stresses above those listed in the Table "Absolute Maximum Ratings" 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 ex tended periods
may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality document.
Figure 2. DIP Pin Connections
Read Mode
The M27512 has two control functions, both of
which must be logically active in order to obtain
data at the outputs. Chip Enable (E) is the power
control and should be used for device selection.
Output Enable (G) is the output control and should
be used to gate data to the output pins, inde-
pendent of device selection. Assuming that the
addresses are stable, address access time (t
AVQV
)
is equal to the delay from E to output (t
ELQV
). Data
is available at the outputs after delay of t
GLQV
from
the falling edge of G, assuming that E has been low
and the addresses have been stable for at least
t
AVQV
-t
GLQV
.
Standby Mode
The M27512 has a standby mode which reduces
the maximum active power current from 125mA to
40mA. The M27512 is placed in the standby mode
by applying a TTL high signal to the E input. When
in the standby mode, the outputs are in a high
impedance state, independent of the GV
PP
input.
Two Line Output Control
Because EPROMs are usually used in larger mem-
ory arrays, the 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.
A15
A12
A7
A6
A5
A4
A3
A2
A1
A0
Q0
Q1
Q2
VSS
28
1
27
2
26
3
25
4
24
5
23
6
22
7
M27512
21
8
20
9
19
10
18
11
17
12
13
16
14
15
AI00766
VCC
A14
A13
A8
A9
A11
GVPP
A10
E
Q7
Q6
Q5
Q4
Q3
DEVICE OPERATION
The six modes of operations of the M27512 are
listed in the Operating Modes table. A single 5V
power supply is required in the read mode. All
inputs are TTL levels except for GV
PP
and 12V on
A9 for Electronic Signature.
2/11
M27512
DEVICE OPERATION
(cont’d)
For the most efficient use of these two control lines,
E should be decoded and used as the primary
device selecting function, while GV
PP
should be
made a common connection to all devices in the
array and connected to the READ line from the
system control bus. This ensures that all dese-
lected memory devices are in their low power
standby mode and that the output pins are only
active when data is required from a particular mem-
ory device.
System Considerations
The power switching characteristics of fast
EPROMs require careful decoupling of the devices.
The supply current, I
CC
, has three segments that
are of interest to the system designer : the standby
current level, the active current level, and transient
current peaks that are produced by the falling and
rising edges of E. The magnitude of the transient
current peaks is dependent on the capacitive and
inductive loading of the device at the output. The
associated transient voltage peaks can be sup-
pressed by complying with the two line output
control and by properly selected decoupling ca-
pacitors. It is recommenced that a 1µF ceramic
capacitor be used on every device between V
CC
and V
SS
. This should be a high frequency capacitor
of low inherent inductance and should be placed
as close to the device as possible. In addition, a
4.7µF bulk electrolytic capacitor should be used
between V
CC
and V
SS
for every eight devices. The
Table 3. Operating Modes
Mode
Read
Output Disable
Program
Verify
Program Inhibit
Standby
Electronic Signature
Note:
X = V
IH
or V
IL
, V
ID
= 12V
±
0.5%.
bulk capacitor should be located near the power
supply connection point. The purpose of the bulk
capacitor is to overcome the voltage drop caused
by the inductive effects of PCB traces.
Programming
When delivered, and after each erasure, all bits of
the M27512 are in the “1" state. Data is introduced
by selectively programming ”0s" into the desired bit
locations. Although only “0s” will be programmed,
both “1s” and “0s” can be present in the data word.
The only way to change a “0" to a ”1" is by ultraviolet
light erasure. The M27512 is in the programming
mode when GV
PP
input is at 12.5V and E is at
TTL-low. The data to be programmed is applied 8
bits in parallel to the data output pins. The levels
required for the address and data inputs are TTL.
The M27512 can use PRESTO Programming Algo-
rithm that drastically reduces the programming
time (typically less than 50 seconds). Nevertheless
to achieve compatibility with all programming
equipment, the standard Fast Programming Algo-
rithm may also be used.
Fast Programming Algorithm
Fast Programming Algorithm rapidly programs
M27512 EPROMs using an efficient and reliable
method suited to the production programming en-
vironment. Programming reliability is also ensured
as the incremental program margin of each byte is
continually monitored to determine when it has
been successfully programmed. A flowchart of the
M27512 Fast Programming Algorithm is shown in
Figure 8.
E
V
IL
V
IL
V
IL
Pulse
V
IH
V
IH
V
IH
V
IL
GV
PP
V
IL
V
IH
V
PP
V
IL
V
PP
X
V
IL
A9
X
X
X
X
X
X
V
ID
Q0 - Q7
Data Out
Hi-Z
Data In
Data Out
Hi-Z
Hi-Z
Codes
Table 4. Electronic Signature
Identifier
Manufacturer’s Code
Device Code
A0
V
IL
V
IH
Q7
0
0
Q6
0
0
Q5
1
0
Q4
0
0
Q3
0
1
Q2
0
1
Q1
0
0
Q0
0
1
Hex Data
20h
0Dh
3/11
M27512
AC MEASUREMENT CONDITIONS
Input Rise and Fall Times
Input Pulse Voltages
Input and Output Timing Ref. Voltages
≤
20ns
0.45V to 2.4V
0.8V to 2.0V
Figure 4. AC Testing Load Circuit
1.3V
1N914
Note that Output Hi-Z is defined as the point where data
is no longer driven.
3.3kΩ
Figure 3. AC Testing Input Output Waveforms
DEVICE
UNDER
TEST
2.0V
0.8V
AI00827
OUT
CL = 100pF
2.4V
0.45V
CL includes JIG capacitance
AI00828
Table 5. Capacitance
(1)
(T
A
= 25
°C,
f = 1 MHz )
Symbol
C
IN
C
OUT
Parameter
Input Capacitance
Output Capacitance
Test Condition
V
IN
= 0V
V
OUT
= 0V
Min
Max
6
12
Unit
pF
pF
Note:
1. Sampled only, not 100% tested.
Figure 5. Read Mode AC Waveforms
A0-A15
tAVQV
E
tGLQV
G
tELQV
Q0-Q7
VALID
tAXQX
tEHQZ
tGHQZ
Hi-Z
DATA OUT
AI00735
4/11
M27512
Table 6. Read Mode DC Characteristics
(1)
(T
A
= 0 to 70
°C
or –40 to 85
°C;
V
CC
= 5V
±
5% or 5V
±
10%; V
PP
= V
CC
)
Symbol
I
LI
I
LO
I
CC
I
CC1
V
IL
V
IH
V
OL
V
OH
Parameter
Input Leakage Current
Output Leakage Current
Supply Current
Supply Current (Standby)
Input Low Voltage
Input High Voltage
Output Low Voltage
Output High Voltage
I
OL
= 2.1mA
I
OH
= –400µA
2.4
Test Condition
0
≤
V
IN
≤
V
CC
V
OUT
= V
CC
E = V
IL
, G = V
IL
E = V
IH
–0.1
2
Min
Max
±10
±10
125
40
0.8
V
CC
+ 1
0.45
Unit
µA
µA
mA
mA
V
V
V
V
Note:
1. V
CC
must be applied simultaneously with or before V
PP
and removed simultaneously or after V
PP
.
Table 7. Read Mode AC Characteristics
(1)
(T
A
= 0 to 70
°C
or –40 to 85
°C;
V
CC
= 5V
±
5% or 5V
±
10%; V
PP
= V
CC
)
Symbol
Alt
Parameter
Test
Condition
E = V
IL
,
G = V
IL
G = V
IL
E = V
IL
G = V
IL
E = V
IL
E = V
IL
,
G = V
IL
0
0
0
M27512
-2, -20
blank, -2 5
-3
Unit
Min Max Min Max Min Max
t
AVQV
t
ELQV
t
GLQV
t
EHQZ
t
GHQZ
(2)
(2)
t
ACC
t
CE
t
OE
t
DF
t
DF
t
OH
Address Valid to Output Valid
Chip Enable Low to Output Valid
Output Enable Low to Output Valid
Chip Enable High to Output Hi-Z
Output Enable High to Output Hi-Z
Address Transition to Output
Transition
200
200
75
55
55
0
0
0
250
250
100
60
60
0
0
0
300
300
120
105
105
ns
ns
ns
ns
ns
ns
t
AXQX
Notes:
1. V
CC
must be applied simultaneously with or before V
PP
and removed simultaneously or after V
PP
.
2. Sampled only, not 100% tested.
Table 8. Programming Mode DC Characteristics
(1)
(T
A
= 25
°C;
V
CC
= 6.25V
±
0.25V; V
PP
= 12.75V
±
0.25V)
Symbol
I
LI
I
CC
I
PP
V
IL
V
IH
V
OL
V
OH
V
ID
Parameter
Input Leakage Current
Supply Current
Program Current
Input Low Voltage
Input High Voltage
Output Low Voltage
Output High Voltage
A9 Voltage
I
OL
= 2.1mA
I
OH
= –400µA
2.4
11.5
12.5
E = V
IL
–0.1
2
Test Condition
V
IL
≤
V
IN
≤
V
IH
Min
Max
±10
150
50
0.8
V
CC
+ 1
0.45
Unit
µA
mA
mA
V
V
V
V
V
Note:
1. V
CC
must be applied simultaneously with or before V
PP
and removed simultaneously or after V
PP
.
5/11
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