32K x 8-Bit CMOS EPROM
fax id: 3013
CY27C256
Cypress Semiconductor Corporation
3901 North First Street
San Jose
CA 95134
408-943-2600
May 1993 Revised August 1994
1CY 27C2 56
Features
Wide speed range
-- 45 ns to 200 ns (commercial and military)
Low power
-- 248 mW (commercial)
-- 303 mW (military)
Low standby power
-- Less than 83 mW when deselected
10% Power supply tolerance
Functional Description
The CY27C256 is a high-performance 32,768-word by 8-bit
CMOS EPROM. When disabled (CE HIGH), the CY27C256
automatically powers down into a low-power stand-by mode.
The CY27C256 is packaged in the industry standard 600-mil
DIP, PLCC, and TSOP packages. The CY27C256 is also avail-
able in a CerDIP package equipped with an erasure window
to provide for reprogrammability. When exposed to UV light,
the EPROM is erased and can be reprogrammed. The mem-
ory cells utilize proven EPROM floating gate technology and
byte-wide intelligent programming algorithms.
The CY27C256 offers the advantage of lower power and su-
perior performance and programming yield. The EPROM cell
requires only 12.5V for the super voltage, and low current re-
quirements allow for gang programming. The EPROM cells
allow each memory location to be tested 100% because each
location is written into, erased, and repeatedly exercised prior
to encapsulation. Each EPROM is also tested for AC perfor-
mance to guarantee that after customer programming, the
product will meet both DC and AC specification limits.
Reading the CY27C256 is accomplished by placing active
LOW signals on OE and CE. The contents of the memory location
addressed by the address lines (A
0
- A
14
) will become available on
the output lines (O
0
- O
7
).
Note:
1.
For PLCC only: Pins 1 and 17 are common and tied to the die attach pad. They must therefore be DU (don't use) for the PLCC package.
Logic Block Diagram
Pin Configurations
27c2561
A
12
A
11
A
9
A
8
A
7
A
6
A
5
A
4
A
3
A
2
A
1
A
0
POWERDOWN
O
7
O
6
O
5
O
4
O
3
O
2
O
1
O
0
CE
256 x 1024
PROGRAMABLE
ARRAY
8 x 1 OF 128
MULTIPLEXER
A
10
A
13
A
14
1
2
3
4
5
6
7
8
9
10
11
12
16
17
18
19
20
24
23
22
21
13
14
25
28
27
26
12
31
4
5
6
7
8
9
10
3 2 1
30
13
14151617
26
25
24
23
22
21
11
181920
27
28
29
32
15
A
12
A
7
A
6
A
5
A
4
A
3
A
2
A
1
A
0
O
0
O
1
O
2
GND
V
CC
A
13
A
8
A
9
O
7
O
6
O
4
O
5
O
3
27c2562
27c2563
A
9
A
11
O
7
O
6
A
8
V
PP
A
14
27C256
A
11
OE
A
10
CE
NC
A
5
A
4
A
3
A
2
A
6
A
1
O
0
A
0
NC
OE
A
10
CE
DIP/Flatpack
27C256
ROW
LCC/PLCC
[1]
OE
ADDRESS
COLUMN
ADDRESS
ADDRESS
DECODER
CY27C256
2
Maximum Ratings
(Above which the useful life may be impaired. For user guide-
lines, not tested.)
Storage Temperature ................................. -65
C to +150
C
Ambient Temperature with
Power Applied............................................. -55
C to +125
C
Supply Voltage to Ground Potential ................- 0.5V to +7.0V
DC Voltage Applied to Outputs
in High Z State................................................ -0.5V to +7.0V
DC Input Voltage .............................................-3.0V to +7.0V
DC Program Voltage .................................................... 13.0V
Static Discharge Voltage ........................................... >2001V
(per MIL-STD-883, Method 3015)
Latch-Up Current ..................................................... >200 mA
UV Exposure ................................................ 7258 Wsec/cm
2
Selection Guide
27C256-45
27C256-55
27C256-70
27C256-90
27C256-120
27C256-150
27C256-200
Maximum Access Time (ns)
45
55
70
90
120
150
200
Maximum
Operating
Current (mA)
Com'l
45
45
45
45
45
45
45
Mil
55
55
55
55
55
55
55
Standby Current
(mA)
Com'l
15
15
15
15
15
15
15
Mil
20
20
20
20
20
20
20
Chip Select Time (ns)
45
55
70
90
120
150
200
Output Enable Time (ns)
15
20
25
30
30
40
40
Pin Configurations
1
2
3
4
5
6
7
8
9
10
11
14
19
20
24
23
22
21
25
28
27
26
Top View
28-Pin TSOP
12
13
16
15
17
18
OE
A
11
A
9
A
8
A
13
A
14
V
CC
V
PP
A
12
A
7
A
10
CE
O
7
O
6
O
5
O
4
O
3
GND
O
2
O
0
O
1
A
0
A
6
A
5
A
1
A
2
1
2
3
4
5
6
7
8
9
10
11
14
19
20
24
23
22
21
25
28
27
26
T
op View
32-Pin TSOP
12
13
29
32
31
30
16
15
17
18
OE
A
1
1
A
9
A
8
A
1
3
NC
A
1
4
V
CC
V
P
P
NC
A
1
2
A
7
A
6
A
5
NC
A
10
CE
O
7
O
6
O
5
O
4
O
3
GND
O
2
O
1
NC
O
0
A
0
A
4
A
3
A
1
A
2
A
4
A
3
27c2564
27c2565
27C256T
27C256
CY27C256
3
Operating Range
Range
Ambient
Temperature
V
CC
Commercial
0
C to +70
C
5V
10%
Industrial
[2]
-40
C to +85
C
5V
10%
Military
[3]
-55
C to +125
C
5V
10%
Electrical Characteristics
Over the Operating Range
[4]
27C256-45, 55, 70, 90,
120, 150, 200
Parameter
Description
Test Conditions
Min.
Max.
Unit
V
OH
Output HIGH Voltage
V
CC
= Min., I
OH
= 4.0 mA
2.4
V
V
OL
Output LOW Voltage
V
CC
= Min., I
OL
= 16.0 mA
[5]
0.4
V
V
IH
Input HIGH Level
Guaranteed Input Logical HIGH Voltage for All
Inputs
2.0
V
CC
V
V
IL
Input LOW Level
Guaranteed Input Logical LOW Voltage for All
Inputs
0.3
0.8
V
I
IX
Input Current
GND < V
IN
< V
CC
10
+10
A
I
OZ
Output Leakage Current
GND < V
OUT
< V
CC
,
Output Disabled
Commercial
10
+10
A
Military
40
+40
I
OS
Output Short Circuit Current
[6]
V
CC
= Max., V
OUT
= GND
20
90
mA
I
CC
Power Supply Current
V
CC
= Max., V
IN
=V
IH
,
I
OUT
= 0 mA, CE=V
IL
,
OE = V
IH
Commercial
45
mA
Military
55
I
SB
Standby Supply Current
V
CC
= Max., CE = V
IH
Commercial
15
mA
Military
20
V
PP
Programming Supply Voltage
12
13
V
I
PP
Programming Supply Current
50
mA
V
IHP
Input HIGH Programming
Voltage
3.0
V
V
ILP
Input LOW Programming
Voltage
0.4
V
Capacitance
[7]
Parameter
Description
Test Conditions
Max.
Unit
C
IN
Input Capacitance
T
A
= 25
C, f = 1 MHz,
V
CC
= 5.0V
10
pF
C
OUT
Output Capacitance
10
pF
Notes:
2.
Contact a Cypress representative for information on industrial temperature range specifications.
3.
T
A
is the "instant on" case temperature.
4.
See the last page of this specification for Group A subgroup testing information.
5.
I
OL
=12.0 mA for military devices.
6.
For test purposes, not more than one output at a time should be shorted. Short circuit test duration should not exceed 30 seconds.
7.
See Introduction to CMOS PROMs in this Data Book for general information on testing.
CY27C256
4
AC Test Loads and Waveforms
27c2566
27c2567
90%
10%
3.0V
GND
90%
10%
ALL INPUT PULSES
5V
OUTPUT
30 pF
INCLUDING
JIG AND
SCOPE
5V
OUTPUT
5 pF
INCLUDING
JIG AND
SCOPE
(a) Normal Load
(b) High Z Load
5 ns
5 ns
OUTPUT
R1 250
(329
MIL)
R2 167
(202
MIL)
100
Equivalent to:
TH VENIN EQUIVALENT
2.00V
R2 167
(202
MIL)
R1 250
(329
MIL)
OUTPUT
125
1.9V
Commercial
Military
Switching Characteristics
Over the Operating Range
[4,7 ]
27C256-45
27C256-
55
27C256-70
27C256-90
Parameter
Description
Min.
Max.
Min.
Max.
Min.
Max.
Min.
Max.
Unit
t
AA
Address to Output Valid
45
55
70
90
ns
t
HZOE
Outpout Enable Inactive to High Z
15
20
25
25
ns
t
OE
Output Enable Active to Output Valid
15
20
25
30
ns
t
HZCE
Chip Enable Inactive to High Z
20
25
25
25
ns
t
ACE
Chip Enable Active to Output Valid
45
55
70
90
ns
t
PU
Chip Enable Active to Power Up
0
0
0
0
ns
t
PD
Chip Enable Inactive to Power Down
45
55
70
90
ns
t
OH
Output Hold from Address Change
0
0
0
0
ns
Switching Characteristics
Over the Operating Range
[4, 7]
27C256-120
27C256-150
27C256-200
Parameter
Description
Min.
Max.
Min.
Max.
Min.
Max.
Unit
t
AA
Address to Output Valid
120
150
200
ns
t
HZOE
Outpout Enable Inactive to High Z
30
30
30
ns
t
OE
Output Enable Active to Output Valid
30
40
40
ns
t
HZCE
Chip Enable Inactive to High Z
30
30
30
ns
t
ACE
Chip Enable Active to Output Valid
120
150
200
ns
t
PU
Chip Enable Active to Power Up
0
0
0
ns
t
PD
Chip Enable Inactive to Power Down
120
150
200
ns
t
OH
Output Hold from Address Change
0
0
0
ns
CY27C256
5
Erasure Characteristics
Wavelengths of light less than 4000 begin to erase the
27C256 in the windowed package. For this reason, an opaque
label should be placed over the window if the EPROM is ex-
posed to sunlight or fluorescent lighting for extended periods
of time.
The recommended dose of ultraviolet light for erasure is a
wavelength of 2537 for a minimum dose (UV intensity mul-
tiplied by exposure time) of 25 Wsec/cm2. For an ultraviolet
lamp with a 12 mW/cm
2
power rating, the exposure time would
be approximately 35 minutes. The CY27C256 needs to be
within 1 inch of the lamp during erasure. Permanent damage
may result if the EPROM is exposed to high-intensity UV light
for an extended period of time. 7258 Wsec/cm
2
is the recom-
mended maximum dosage.
Programming Modes
Programming support is available from Cypress as well as
from a number of third-party software vendors. For detailed
programming information, including a listing of software pack-
ages, please see the EPROM Programming Information locat-
ed at the end of this section. Programming algorithms can be
obtained from any Cypress representative.
Switching Waveform
t
OH
t
PU
t
PD
t
AA
27c2568
(t
OE
)
t
ACE
50%
50%
A
0
- A
14
ADDRESS
I
CC
SUPPLY
CURRENT
OE, CE
O
0
- O
7
PREVIOUS DATA VALID
DATA VALID
POWERDOWN CONTROLLED BY CE
(t
HZOE
)
t
HZCE
HIGH Z
Table 1. CY27C256 Mode Selection.
Mode
Pin Function
[8]
A
14
-A
0
OE
CE
V
PP
O
7
-O
0
Read
A
14
-A
0
V
IL
V
IL
X
[9]
O
7
-O
0
Output Disable
A
14
-A
0
V
IH
V
IL
X
High Z
Power Down
A
14
-A
0
X
V
IH
X
High Z
Notes:
8.
X can be V
IL
or V
IH
9.
V
PP
should not exceed V
CC
in read mode.
CY27C256
6
Typical DC and AC Characteristics
1.0
0.8
0.7
4.0
4.5
5.0
5.5
6.0
-100
-50
150
1.2
1.1
1.2
1.1
1.0
0.9
4.0
4.5
5.0
5.5
6.0
SUPPLY VOLTAGE (V)
NORMALIZED SUPPLYCURRENT
vs. SUPPLY VOLTAGE
NORMALIZED SUPPLY CURRENT
vs. AMBIENT TEMPERATURE
AMBIENT TEMPERATURE
(
C)
SUPPLY VOLTAGE (V)
NORMALIZED ACCESS TIME
vs. SUPPLY VOLTAGE
0.6
0.9
AMBIENT TEMPERATURE (
C)
NORMALIZED ACCESSTIME
vs. TEMPERATURE
1.0
0.9
0.8
0.8
60
50
40
30
20
10
0
1.0
2.0
3.0
OUTPUT VOLTAGE (V)
30.0
25.0
20.0
15.0
10.0
5.0
0
200
400
600
800
CAPACITANCE (pF)
TYPICAL ACCESS TIME CHANGE
vs. OUTPUT LOADING
4.0
0.0
1000
V
CC
=4.5V
T
A
=25
C
T
A
=25
C
f = f
MAX
0
OUTPUT SOURCE CURRENT
vs. OUTPUT VOLTAGE
1.4
1.2
1.1
1.3
0.7
1.3
0
50
100
0.85
0.95
1.05
1.15
1.25
-100
-50
150
1.3
1.2
1.1
1.0
0.9
0.8
1.4
0
50
100
V
CC
=5V
T
A
=25
C
1.15
1.05
0.95
0.85
CYCLE TIME(ns)
NORMALIZED SUPPLYCURRENT
vs. ACCESS TIME
0.75
0.8
0.9
1.0
1.1
1.2
0
100
200
300
400 500
V
CC
=5.6V
T
A
=25
C
150
175
125
75
50
25
0.0
1.0
2.0
3.0
0
100
OUTPUT VOLTAGE(V)
OUTPUT SINK CURRENT
vs. OUTPUT VOLTAGE
V
CC
=5.0V
T
A
=25
C
4.0
CY27C256
7
Ordering Information
[10]
Speed
(ns)
Ordering Code
Package
Name
Package Type
Operating
Range
45
CY27C256-45JC
J65
32-Pin Rectangular Plastic Leaded Chip Carrier
Commercial
CY27C256-45PC
P15
28-Lead (600-Mil) Molded DIP
CY27C256-45WC
W16
28-Lead (600-Mil) Windowed CerDIP
CY27C256-45ZC
Z32
32-Lead Thin Small Outline Package
CY27C256-45WMB
W16
28-Lead (600-Mil) Windowed CerDIP
Military
55
CY27C256-55JC
J65
32-Pin Rectangular Plastic Leaded Chip Carrier
Commercial
CY27C256-55PC
P15
28-Lead (600-Mil) Molded DIP
CY27C256-55WC
W16
28-Lead (600-Mil) Windowed CerDIP
CY27C256-55ZC
Z32
32-Lead Thin Small Outline Package
CY27C256-55WMB
W16
28-Lead (600-Mil) Windowed CerDIP
Military
70
CY27C256-70JC
J65
32-Pin Rectangular Plastic Leaded Chip Carrier
Commercial
CY27C256-70PC
P15
28-Lead (600-Mil) Molded DIP
CY27C256-70WC
W16
28-Lead (600-Mil) Windowed CerDIP
CY27C256-70ZC
Z32
32-Lead Thin Small Outline Package
CY27C256-70WMB
W16
28-Lead (600-Mil) Windowed CerDIP
Military
90
CY27C256-90JC
J65
32-Pin Rectangular Plastic Leaded Chip Carrier
Commercial
CY27C256-90PC
P15
28-Lead (600-Mil) Molded DIP
CY27C256-90WC
W16
28-Lead (600-Mil) Windowed CerDIP
CY27C256-90ZC
Z32
32-Lead Thin Small Outline Package
CY27C256-90WMB
W16
28-Lead (600-Mil) Windowed CerDIP
Military
120
CY27C256-120JC
J65
32-Pin Rectangular Plastic Leaded Chip Carrier
Commercial
CY27C256-120PC
P15
28-Lead (600-Mil) Molded DIP
CY27C256-120WC
W16
28-Lead (600-Mil) Windowed CerDIP
CY27C256-120ZC
Z32
32-Lead Thin Small Outline Package
CY27C256-120WMB
W16
28-Lead (600-Mil) Windowed CerDIP
Military
150
CY27C256-150JC
J65
32-Pin Rectangular Plastic Leaded Chip Carrier
Commercial
CY27C256-150PC
P15
28-Lead (600-Mil) Molded DIP
CY27C256-150WC
W16
28-Lead (600-Mil) Windowed CerDIP
CY27C256-150ZC
Z32
32-Lead Thin Small Outline Package
CY27C256-150WMB
W16
28-Lead (600-Mil) Windowed CerDIP
Military
200
CY27C256-200JC
J65
32-Pin Rectangular Plastic Leaded Chip Carrier
Commercial
CY27C256-200PC
P15
28-Lead (600-Mil) Molded DIP
CY27C256-200WC
W16
28-Lead (600-Mil) Windowed CerDIP
CY27C256-200ZC
Z32
32-Lead Thin Small Outline Package
CY27C256-200WMB
W16
28-Lead (600-Mil) Windowed CerDIP
Military
Notes:
10. Most of these products are available in industrial temperature range. Contact a Cypress representative for specifications and product availability.
CY27C256
8
MILITARY SPECIFICATIONS
Group A Subgroup Testing
Document #: 38-00245-D
Ordering Information
(continued)
Speed
(ns)
Ordering Code
Package
Name
Package Type
Operating
Range
45
CY27C256T-45WC
W22
28-Lead (300-Mil) Windowed CerDIP
Commercial
CY27C256T-45ZC
Z28
28-Thin Small Outline Package
CY27C256T-45WMB
W22
28-Lead (300-Mil) Windowed CerDIP
Military
55
CY27C256T-55WC
W22
28-Lead (300-Mil) Windowed CerDIP
Commercial
CY27C256T-55ZC
Z28
28-Thin Small Outline Package
CY27C256T-55WMB
W22
28-Lead (300-Mil) Windowed CerDIP
Military
70
CY27C256T-70WC
W22
28-Lead (300-Mil) Windowed CerDIP
Commercial
CY27C256T-70ZC
Z28
28-Thin Small Outline Package
CY27C256T-70WMB
W22
28-Lead (300-Mil) Windowed CerDIP
Military
DC Characteristics
Parameter
Subgroups
V
OH
1, 2, 3
V
OL
1, 2, 3
V
IH
1, 2, 3
V
IL
1, 2, 3
I
IX
1, 2, 3
I
OZ
1, 2, 3
I
CC
1, 2, 3
I
SB
1, 2, 3
Switching Characteristics
Parameter
Subgroups
t
AA
7, 8, 9, 10, 11
t
OE
7, 8, 9, 10, 11
t
ACE
7, 8, 9, 10, 11
CY27C256
9
Package Diagrams
32-Lead Plastic Leaded Chip Carrier J65
28-Lead (600-Mil) Molded DIP P15
CY27C256
10
Package Diagrams
(Continued)
28-Lead (600-Mil) Windowed CerDIP W16
MIL-STD-1835
D-10 Config.A
28-Lead Thin Small Outline Package Z28
CY27C256
Cypress Semiconductor Corporation, 1994. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use
of any circuitry other than circuitry embodied in a Cypress Semiconductor product. Nor does it convey or imply any license under patent or other rights. Cypress Semiconductor does not authorize
its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress
Semiconductor products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress Semiconductor against all charges.
Package Diagrams
(Continued)
32-Lead Thin Small Outline Package Z32
PDF 
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