CYPRESS CY7C197 User Manual
97
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CY7C197
256Kx1 Static RAM
Features
vided by an active LOW Chip Enable (CE
ers. The CY7C197 has an automatic power-down feature,
• High speed
—12 ns
• CMOS for optimum speed/power
• Low active power
—880 mW
• Low standby power
—220 mW
• TTL-compatible inputs and outputs
• Automatic power-down when deselected
Functional Description
reducing the power consumption by 75% when deselected.
Writing to the device is accomplished when the Chip Enable
) and Write En able (WE) inpu ts are both LOW . Data on the
(CE
input pin (D
the address pins (A
) is written into t he m em ory l ocati on s pec ifi ed o n
IN
through A17).
0
Reading the device is accomplished by taking chip enable
) LOW while Write Enable (WE) remains HIGH. Under
(CE
these conditions th e contents of the memory locati on specifie d
on the address pins will appear on the da ta output (D
The output pin stays in a high-impedance state when Chip
Enable (CE
) is HIGH or Wri te Enable (W E) is LOW.
The CY7C197 utilizes a die coat to insure alpha immunity.
The CY7C197 is a high-perfo rmance CMO S static RAM org anized as 256K words by 1 bit. Easy memory exp ansio n is pr o-
LogicBlock Diagram Pin Configurations
DI
DIP/SOJ
Top View
A
1
D
OUT
WE
GND
0
A
1
A
2
A
3
A
4
A
5
A
6
A
7
A
8
2
3
4
5
7C197
6
7
8
9
10
11
12 13
INPUT BUFFER
A
13
A
14
A
15
A
16
A
17
A
0
A
1
A
2
A
A
ROW DECODER
3
4
1024 x 256
ARRAY
COLUMN
DECODER
SENSE AMPS
POWER
DOWN
DO
CE
V
24
CC
A
23
17
A
22
16
A
21
15
A
20
14
A
19
13
A
18
12
A
17
11
A
10
16
A
15
9
14
D
IN
CE
C197-2 C197-3
) and three-state driv -
) pin.
OUT
LCC
Top View
17
2
CC
V
A1A0A
A
28
321 27
4
NC
5
A
3
A
6
4
7
A
5
8
A
6
A
9
7
A
10
8
D
11
OUT
12
1314151617
7C197
WE
GND
CE
26
NC
25
A
16
24
A
15
23
A
14
22
A
13
21
A
12
20
A
11
A
19
10
18
NCNC
9
IN
A
D
A
A5A
A
A9A10A11A
7
6
8
12
WE
C197-1
Selection Guide
7C197-12 7C197-15 7C197-20 7C197-25 7C197-35 7C197-45
Maximum Access Time (ns) 12 15 20 25 35 45
Maximum Operating Current (mA) 150 140 135 95 95
Maximum Standby Current (mA) 30 30 30 30 30 30
Cypress Semiconductor Corporation • 3901 North First Street • San Jose • CA 95134 • 408-943-2600
Document #: 38-05049 Rev. ** Revised August 24, 2001
[1]
Maximum Ratings
(Above which the useful life may be im pai red. For user guidelines, not tested.)
Storage Temperature .....................................−65
Ambient Temperature with
Power Applied..................................................−55
°C to +150°C
°C to +125°C
DC Input Voltage
Output Current into Outputs (LOW).............................20 mA
Static Discharge Voltage.......................................... >2001V
(per MIL-STD-883, Method 3015)
Latch-Up Current.................................................... >200 mA
Operating Range
Supply Voltage to Ground Potential
(Pin 24 to Pin 12).................................................−0.5V to +7.0V
DC Voltage Applied to Outputs
in High Z State
[1]
.......................................−0.5V to VCC + 0.5V
Range
Commercial 0°C to +70°C 5V ± 10%
Electrical Characteristics Ov er the Op erat ing Range
Parameter Description Test Conditions
V
OH
V
OL
V
IH
V
IL
I
IX
I
OZ
I
OS
I
CC
I
SB1
I
SB2
Notes:
1. V
(min.)
2. Not more than one output should be shorted at one time. Duration of the short circuit should not exceed 30 seconds.
3. A pull-up resistor to V
Output HIGH Voltage VCC = Min., IOH = −4.0 mA 2.4 2.4 V
Output LOW Voltage VCC = Min. IOL=12.0 mA 0.4 0.4 V
Input HIGH Voltage 2.2 V
Input LOW Voltage
Input Load Current GND < VI < V
[1]
CC
Output Leakage Current GND < VO < VCC, Output Disabled −5+5−5+5µA
Output Short
Circuit Current
[2]
VCC Operating
Supply Current
Automatic CE Power-Down
Current—TTL Inputs
[3]
Automatic CE Power-Down
Current—CMOS Inputs
= −2.0V for pulse durations of less than 20 ns.
on the CE input is required to keep the device deselected during VCC power-up, otherwise ISB will exceed values given.
CC
VCC = Max., V
VCC = Max., I
MAX
= 1/t
f = f
= GND −300 −300 mA
OUT
= 0 mA,
OUT
RC
Max. VCC, CE > VIH, VIN > VIH or
< VIL, f = f
V
IN
Max. VCC, CE > VCC − 0.3V,
[3]
> VCC − 0.3V or VIN < 0.3V
V
IN
MAX
....................................−0.5V to VCC + 0.5V
Temperature V
7C197-12 7C197-15
−0.5 0.8 −0.5 0 .8 V
−5+5−5+5µA
CY7C197
Ambient
CC
CC
+ 0.3V
150 140 mA
30 30 mA
10 10
2.2 V
+0.3V
CC
UnitMin. Max. Min. Max.
V
mA
Document #: 38-05049 Rev. ** Page 2 of 10
Electrical Characteristics Ov er the Op erat ing Range (continued)
CY7C197
Parameter Description Test Conditions
V
OH
V
OL
V
IH
V
IL
I
IX
I
OZ
I
OS
I
CC
I
SB1
I
SB2
Capacitance
Output HIGH Voltage VCC = Min., IOH = −4.0 mA 2.4 2.4 V
Output LOW Voltage VCC = Min. IOL=12.0mA 0.4 0.4 V
Input HIGH Voltage 2.2 V
Input LOW Voltage
Input Load Current GND < VI < V
[1]
CC
Output Leakage Current GND < VO < VCC, Output Disabled −5 +5 −5 +5 µA
Output Short
Circuit Current
[2]
VCC Operating
Supply Current
Automatic CE Power Down
Current—TTL Inputs
[3]
Automatic CE Power-Down
Current—CMOS Inputs
[4]
VCC = Max., V
VCC = Max., I
MAX
= 1/t
f = f
= GND −300 −300 mA
OUT
= 0 mA,
OUT
RC
Max. VCC, CE > VIH, VIN > VIH or
< VIL, f = f
V
IN
Max. VCC, CE > VCC − 0.3V,
[3]
> VCC − 0.3V or VIN < 0.3V
V
IN
MAX
Parameter Description Test Conditions Max. Unit
C
C
IN
OUT
Input Capacitance TA = 25°C, f = 1 MHz,
= 5.0V
V
Output Capacitance 10 pF
CC
7C197-20
7C197-25, 35, 45
UnitMin. Max. Min. Max.
CC
+ 0.3V
2.2 V
+ 0.3V
CC
−0.5 0.8 −0.5 0.8 V
−5 +5 −5 +5 µA
135 95 mA
30 30 mA
15 15 mA
8 pF
V
5V
OUTPUT
INCLUDING
[5]
5pF
JIG AND
SCOPE
R1 329
Ω
R2
Ω
255
(255Ω MIL)
C197-4
AC Test Loads and Wavefor ms
R1 329
Ω
5V
OUTPUT
30 pF
INCLUDING
JIG AND
SCOPE
Equivalent to: THÉ VENIN EQUIVALENT
OUTPUT 1.90V
R2
Ω
202
(255Ω MIL)
(a) (b)
125Ω
Commercial
Notes:
4. Tested initially and after any design or process changes that may affect these parameters.
5. t
= < 3 ns for the -12 and -15 speeds. tr = < 5 ns for the -20 and slower speeds.
r
3.0V
GND
10%
<t
ALL INPUT PULSES
90%
r
90%
10%
<t
r
C197-5
Document #: 38-05049 Rev. ** Page 3 of 10
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