SGS Thomson Microelectronics M27C256B-15F1, M27C256B-12C1TR, M27C256B-12C1, M27C256B-12B6, M27C256B-12B3 Datasheet
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1/16April 2001
M27C256B
256 Kbit (32Kb x 8) UV EPROM and OTP EPROM
■ 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
DESCRIPTION
The M27C256B is a 256 Kbit EPROM offered in
the two ranges UV (ultra violet erase) and OTP
(one timeprogrammable). Itis ideally suitedformicroprocessor systems and is organized as32,768
by 8 bits.
The FDIP28W (window ceramic frit-seal package)
has a transparent lid which allows the user to expose thechipto ultraviolet lightto erase thebitpattern. A new pattern can then be written to the
device by following the programmingprocedure.
For applications where the content is programmed
only one time and erasure is not required, the
M27C256B is offered in PDIP28, PLCC32 and
TSOP28 (8 x 13.4 mm) packages.
Figure 1. Logic Diagram
AI00755B
15
A0-A14 Q0-Q7
V
PP
V
CC
M27C256B
G
E
V
SS
8
1
28
28
1
FDIP28W (F) PDIP28 (B)
PLCC32 (C) TSOP28 (N)
8 x 13.4 mm
M27C256B
2/16
Figure 2B. LCC Connections
AI00757
A13
A8
A10
Q4
17
A0
NC
Q0
Q1
Q2
DU
Q3
A6
A3
A2
A1
A5
A4
9
A14
A9
1
V
PP
A11
Q6
A7
Q7
32
DU
V
CC
M27C256B
A12
NC
Q5
G
E
25
V
SS
Figure 2A. DIP Connections
A1
A0
Q0
A7
A4
A3
A2
A6
A5
A13
A10
A8
A9
Q7
A14
A11
G
E
Q5Q1
Q2
Q3V
SS
Q4
Q6
A12
V
PP
V
CC
AI00756
M27C256B
8
1
2
3
4
5
6
7
9
10
11
12
13
14
16
15
28
27
26
25
24
23
22
21
20
19
18
17
Figure 2C. TSOP Connections
A1
A0
Q0
A5
A2
A4
A3
A9
A11
Q7
A8
G
E
Q5
Q1
Q2
Q3
Q4
Q6
A13
A14
A12
A6
V
PP
V
CC
A7
AI00614B
M27C256B
28
1
22
78
14
15
21
V
SS
A10
Table 1. Signal Names
A0-A14 Address Inputs
Q0-Q7 Data Outputs
E Chip Enable
G Output Enable
V
PP
Program Supply
V
CC
Supply Voltage
V
SS
Ground
NC Not Connected Internally
DU Don’t Use
3/16
M27C256B
Table 2. Absolute Maximum Ratings
(1)
Note: 1. Except for the rating ”Operating Temperature Range”, stressesabove 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 atthese 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. Referalso tothe STMicroelectronics SUREProgram and otherrelevant quality documents.
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
CC
+0.5V withpossible overshoot to VCC+2V for a period less than20ns.
3. Depends on range.
Table 3. Operating Modes
Note: X = VIHor VIL,VID= 12V ± 0.5V.
Table 4. Electronic Signature
Symbol Parameter Value Unit
T
A
Ambient Operating Temperature
(3)
–40 to 125 °C
T
BIAS
Temperature Under Bias –50 to 125 °C
T
STG
Storage Temperature –65 to 150 °C
V
IO
(2)
Input or Output Voltage (except A9) –2 to 7 V
V
CC
Supply Voltage –2 to 7 V
V
A9
(2)
A9 Voltage –2 to 13.5 V
V
PP
Program Supply Voltage –2 to 14 V
Mode E G A9
V
PP
Q7-Q0
Read
V
IL
V
IL
X
V
CC
Data Out
Output Disable V
IL
V
IH
XVCCHi-Z
Program
V
IL
Pulse V
IH
X
V
PP
Data In
Verify V
IH
V
IL
XVPPData Out
Program Inhibit
V
IH
V
IH
X
V
PP
Hi-Z
Standby
V
IH
XX
V
CC
Hi-Z
Electronic Signature
V
IL
V
IL
V
ID
V
CC
Codes
Identifier A0 Q7 Q6 Q5 Q4 Q3 Q2 Q1 Q0 Hex Data
Manufacturer’s Code
V
IL
00100000 20h
Device Code
V
IH
10001101 8Dh
M27C256B
4/16
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 levels except for VPPand 12V on A9 for Electronic
Signature.
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) is the power
control and should be used for device selection.
Output Enable(G) isthe outputcontrol and should
be used to gate data to the output pins, independent of device selection. Assuming that the ad-
dresses are stable, the address access time
(t
AVQV
) is equal to the delay from E to output
(t
ELQV
). Data is available at the output after delay
of t
GLQV
from the falling edge of G, assuming that
E has been low andthe addresses have been stable for at least t
AVQV-tGLQV
.
Standby Mode
The M27C256B has a standby modewhich reduces the supply current from 30mA to 100µA. The
M27C256B is placed in the standby mode by applying a CMOS high signalto the E input. When in
the standby mode, theoutputs are ina high impedance state,independent of the G input.
Table 5. AC Measurement Conditions
High Speed Standard
Input Rise and FallTimes ≤ 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 3. AC Testing Input Output Waveform
AI01822
3V
High Speed
0V
1.5V
2.4V
Standard
0.4V
2.0V
0.8V
Figure 4. AC Testing Load Circuit
AI01823B
1.3V
OUT
C
L
CL= 30pF for HighSpeed
CL= 100pF for Standard
CLincludes JIG capacitance
3.3kΩ
1N914
DEVICE
UNDER
TEST
Table 6. Capacitance
(1)
(TA=25°C, f = 1 MHz)
Note: 1. Sampled only, not 100% tested.
Symbol Parameter Test Condition Min Max Unit
C
IN
Input Capacitance
V
IN
=0V
6pF
C
OUT
Output Capacitance
V
OUT
=0V
12 pF
5/16
M27C256B
Table 7. Read Mode DC Characteristics
(1)
(TA= 0 to70°C, –40 to 85°C, –40 to 105°C or –40 to 125°C; VCC=5V±5% or 5V ± 10%; VPP=VCC)
Note: 1. VCCmust be applied simultaneously with or before VPPand removed simultaneously or after VPP.
2. Maximum DC voltage on Output is V
CC
+0.5V.
Table 8A. Read Mode AC Characteristics
(1)
(TA= 0 to70°C, –40 to 85°C, –40 to 105°C or –40 to 125°C; VCC=5V±5% or 5V ± 10%; VPP=VCC)
Note: 1. VCCmust be applied simultaneously with or before VPPand removed simultaneously or after VPP.
2. Sampled only, not 100% tested.
3. Speed obtained with High Speed AC measurement conditions.
Symbol Parameter Test Condition Min Max Unit
I
LI
Input Leakage Current 0V ≤ VIN≤ V
CC
±10 µA
I
LO
Output Leakage Current
0V ≤ V
OUT
≤ V
CC
±10 µA
I
CC
Supply Current
E=V
IL
,G=VIL,
I
OUT
= 0mA, f = 5MHz
30 mA
I
CC1
Supply Current (Standby) TTL
E=V
IH
1mA
I
CC2
Supply Current (Standby) CMOS
E>V
CC
– 0.2V
100 µA
I
PP
Program Current
V
PP=VCC
100 µA
V
IL
Input Low Voltage –0.3 0.8 V
V
IH
(2)
Input High Voltage 2
V
CC
+1
V
V
OL
Output Low Voltage
I
OL
= 2.1mA
0.4 V
V
OH
Output High VoltageTTL
I
OH
= –1mA
3.6 V
Output High VoltageCMOS
I
OH
= –100µAV
CC
– 0.7V
V
Symbol Alt Parameter Test Condition
M27C256B
Unit
-45
(3)
-60 -70 -80
Min Max Min Max Min Max Min Max
t
AVQVtACC
Address Valid to
Output Valid
E=V
IL
,G=V
IL
45 60 70 80 ns
t
ELQV
t
CE
Chip Enable Low to
Output Valid
G=V
IL
45 60 70 80 ns
t
GLQVtOE
Output EnableLow to
Output Valid
E=V
IL
25 30 35 40 ns
t
EHQZ
(2)
t
DF
Chip Enable High to
Output Hi-Z
G=V
IL
0 25 0 30 0 30 0 30 ns
t
GHQZ
(2)
t
DF
Output Enable High
to Output Hi-Z
E=V
IL
0 25 0 30 0 30 0 30 ns
t
AXQXtOH
Address Transitionto
Output Transition
E=V
IL
,G=V
IL
0000ns
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:
a. the lowest possible memory power dissipation,
b. complete assurance that output bus contention
will not occur.
For the most efficient use of these two control
lines, Eshould be decoded andused as theprimary device selecting function, while G should be
made a common connection to all devices in the
array and connected to the READ line from the
system controlbus. Thisensures that all deselected memorydevices are in their low power standby
mode and that the output pins are only active
when data is desired from aparticular memorydevice.
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