STK11C88
32Kx8 SoftStore nvSRAM
FEATURES
• 25, 45 ns Read Access & R/W Cycle Time
• Unlimited Read/Write Endurance
• Pin Compatible with Industry Standard SRAMs
• Software-initiated STORE and RECALL
• Automatic RECALL to SRAM on Power Up
• Unlimited RECALL Cycles
• 1 Million Store Cycles
• 100-Year Non-volatile Data Retention
• Single 5V ± 10% Power Supply
• Commercial and Industrial Temperatures
• 28-pin 300-mil and 330-mil SOIC Packages
(RoHS-Compliant)
The Simtek STK11C88 is a 256Kb fast static RAM
with a non-volatile Quantum Trap storage element
included with each memory cell.
The SRAM provides the fast access & cycle times,
ease of use and unlimited read & write endurance of
a normal SRAM.
Data transfers under software control to the non-vol-
atile storage cell (the
STORE
operation). On power
up, data is automatically restored to the SRAM (the
RECALL
operation). RECALL operations are also
available under software control.
The Simtek nvSRAM is the first monolithic non-
volatile memory to offer unlimited writes and reads.
It is the highest performance, most reliable non-
volatile memory available.
DESCRIPTION
BLOCK DIAGRAM
QUANTUM TRAP
512 x 512
A
5
A
6
A
7
A
8
A
9
A
11
A
12
A
13
A
14
DQ
0
DQ
1
DQ
2
DQ
3
DQ
4
DQ
5
DQ
6
DQ
7
ROW DECODER
STORE
STATIC RAM
ARRAY
512 X 512
RECALL
STORE/
RECALL
CONTROL
SOFTWARE
DETECT
A
13
– A
0
INPUT BUFFERS
COLUMN I/O
COLUMN DEC
A
0
A
1
A
2
A
3
A
4
A
10
G
E
W
This product conforms to specifications per the
terms of Simtek standard warranty. The product
has completed Simtek internal qualification testing
and has reached production status.
1
Document Control #ML0012 Rev 0.3
February 2007
STK11C88
PIN CONFIGURATIONS
A14
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
VSS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VCC
W
A13
A8
A9
A11
G
A10
E
DQ7
DQ6
DQ5
DQ4
DQ3
28 - Pin 300 mil SOIC
28 - Pin 330 mil SOIC
PIN DESCRIPTIONS
Pin Name
A
14
-A
0
DQ
7
-DQ
0
E
W
G
V
CC
V
SS
Input
I/O
Input
Input
Input
Power Supply
Power Supply
I/O
Description
Address: The 15 address inputs select one of 32,768 bytes in the nvSRAM array
Data: Bi-directional 8-bit data bus for accessing the nvSRAM
Chip Enable: The active low E input selects the device
Write Enable: The active low W enables data on the DQ pins to be written to the address
location latched by the falling edge of E
Output Enable: The active low G input enables the data output buffers during read cycles.
De-asserting G high caused the DQ pins to tri-state.
Power: 5.0V, ±10%
Ground
Document Control #ML0012 Rev 0.3
February 2007
2
STK11C88
ABSOLUTE MAXIMUM RATINGS
a
Voltage on Input Relative to Ground . . . . . . . . . . . . . .–0.5V to 7.0V
Voltage on Input Relative to V
SS
. . . . . . . . . . –0.6V to (V
CC
+ 0.5V)
Voltage on DQ
0-7
. . . . . . . . . . . . . . . . . . . . . . –0.5V to (V
CC
+ 0.5V)
Temperature under Bias . . . . . . . . . . . . . . . . . . . . . –55°C to 125°C
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . –65°C to 150°C
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1W
DC Output Current (1 output at a time, 1s duration) . . . . . . . . 15mA
Note a: Stresses greater than those listed under “Absolute Maximum
Ratings” may cause permanent damage to the device. This is a
stress rating only, and functional operation of the device at condi-
tions above those indicated in the operational sections of this
specification is not implied. Exposure to absolute maximum rat-
ing conditions for extended periods may affect reliability.
DC CHARACTERISTICS
COMMERCIAL
SYMBOL
I
CC1b
I
CC2c
I
CC3b
I
SB1d
I
SB2d
I
ILK
I
OLK
V
IH
V
IL
V
OH
V
OL
T
A
PARAMETER
MIN
Average V
CC
Current
Average V
CC
Current during
STORE
Average V
CC
Current at t
AVAV
= 200ns
5V, 25°C, Typical
Average V
CC
Current
(Standby, Cycling TTL Input Levels)
V
CC
Standby Current
(Standby, Stable CMOS Input Levels)
Input Leakage Current
Off-State Output Leakage Current
Input Logic “1” Voltage
Input Logic “0” Voltage
Output Logic “1” Voltage
Output Logic “0” Voltage
Operating Temperature
0
2.2
V
SS
– .5
2.4
0.4
70
–40
MAX
97
70
3
10
30
22
750
±1
±5
V
CC
+ .5
0.8
2.2
V
SS
– .5
2.4
0.4
85
MIN
MAX
100
70
3
10
31
23
750
±1
±5
V
CC
+ .5
0.8
mA
mA
mA
mA
mA
mA
μA
μA
μA
V
V
V
V
°C
INDUSTRIAL
UNITS
(V
CC
= 5.0V
±
10%)
NOTES
t
AVAV
= 25ns
t
AVAV
= 45ns
All Inputs Don’t Care, V
CC
= max
W
≥
(V
CC
– 0.2V)
All Others Cycling, CMOS Levels
t
AVAV
= 25ns, E
≥
V
IH
t
AVAV
= 45ns, E
≥
V
IH
E
≥
(V
CC
- 0.2V)
All Others V
IN
≤
0.2V or
≥
(V
CC
– 0.2V)
V
CC
= max
V
IN
= V
SS
to V
CC
V
CC
= max
V
IN
= V
SS
to V
CC
, E or G
≥
V
IH
All Inputs
All Inputs
I
OUT
= – 4mA
I
OUT
= 8mA
Note b: I
CC1
and I
CC3
are dependent on output loading and cycle rate. The specified values are obtained with outputs unloaded.
Note c: I
CC2
is the average current required for the duration of the
STORE
cycle (t
STORE
) .
Note d: E
≥
V
IH
will not produce standby current levels until any nonvolatile cycle in progress has timed out.
AC TEST CONDITIONS
Input Pulse Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to 3V
Input Rise and Fall Times
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≤
5ns
Input and Output Timing Reference Levels . . . . . . . . . . . . . . . 1.5V
Output Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Figure 1
5.0V
CAPACITANCE
e
SYMBOL
C
IN
C
OUT
PARAMETER
Input Capacitance
(T
A
= 25°C, f = 1.0MHz)
MAX
5
7
UNITS
pF
pF
CONDITIONS
ΔV
= 0 to 3V
ΔV
= 0 to 3V
480 Ohms
OUTPUT
255 Ohms
Output Capacitance
Note e: These parameters are guaranteed but not tested.
30 pF
INCLUDING
SCOPE AND
FIXTURE
Figure 1: AC Output Loading
Document Control #ML0012 Rev 0.3
February 2007
3
STK11C88
SRAM READ CYCLES #1 & #2
SYMBOLS
NO.
1
2
3
4
5
6
7
8
9
10
11
PARAMETER
#1, #2
t
ELQV
t
AVAVf
t
AVQVg
t
GLQV
t
AXQXg
t
ELQX
t
EHQZh
t
GLQX
t
GHQZh
t
ELICCHe
t
EHICCLd, e
Alt.
t
ACS
t
RC
t
AA
t
OE
t
OH
t
LZ
t
HZ
t
OLZ
t
OHZ
t
PA
t
PS
Chip Enable Access Time
Read Cycle Time
Address Access Time
Output Enable to Data Valid
Output Hold after Address Change
Chip Enable to Output Active
Chip Disable to Output Inactive
Output Enable to Output Active
Output Disable to Output Inactive
Chip Enable to Power Active
Chip Disable to Power Standby
0
25
0
10
0
45
5
5
10
0
15
25
25
10
5
5
15
MIN
MAX
25
45
45
20
MIN
MAX
45
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
(V
CC
= 5.0V + 10%)
STK11C88-25
STK11C88-45
UNITS
Note f: W must be high during SRAM READ cycles and low during SRAM WRITE cycles.
Note g: I/O state assumes E, G < V
IL
and W > V
IH
; device is continuously selected.
Note h: Measured
±
200mV from steady state output voltage.
SRAM READ CYCLE #1: Address Controlled
f,
g
t
AVAV
ADDRESS
5
t
AXQX
3
2
t
AVQV
DATA VALID
DQ (DATA OUT)
SRAM READ CYCLE #2: E Controlled
f
t
AVAV
ADDRESS
t
ELQV
E
t
ELQX
t
EHQZ
7
6
1
2
t
EHICCL
11
G
4
t
GLQV
t
GHQZ
9
t
GLQX
DQ (DATA OUT)
t
ELICCH
I
CC
STANDBY
10
DATA VALID
8
ACTIVE
Document Control #ML0012 Rev 0.3
February 2007
4
STK11C88
SRAM WRITE CYCLES #1 & #2
SYMBOLS
NO.
#1
12
13
14
15
16
17
18
19
20
21
t
AVAV
t
WLWH
t
ELWH
t
DVWH
t
WHDX
t
AVWH
t
AVWL
t
WHAX
t
WLQZh, i
t
WHQX
#2
t
AVAV
t
WLEH
t
ELEH
t
DVEH
t
EHDX
t
AVEH
t
AVEL
t
EHAX
Alt.
t
WC
t
WP
t
CW
t
DW
t
DH
t
AW
t
AS
t
WR
t
WZ
t
OW
Write Cycle Time
Write Pulse Width
Chip Enable to End of Write
Data Set-up to End of Write
Data Hold after End of Write
Address Set-up to End of Write
Address Set-up to Start of Write
Address Hold after End of Write
Write Enable to Output Disable
Output Active after End of Write
5
PARAMETER
MIN
25
20
20
10
0
20
0
0
10
5
MAX
MIN
45
30
30
15
0
30
0
0
15
MAX
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
(V
CC
= 5.0V + 10%)
STK11C88-25
STK11C88-45
UNITS
Note i:
Note j:
If W is low when E goes low, the outputs remain in the high-impedance state.
E or W must be
≥
V
IH
during address transitions.
SRAM WRITE CYCLE #1: W Controlled
j
12
t
AVAV
ADDRESS
14
t
ELWH
E
17
t
AVWH
13
t
WLWH
15
t
DVWH
DATA IN
20
t
WLQZ
DATA OUT
PREVIOUS DATA
HIGH IMPEDANCE
DATA VALID
19
t
WHAX
18
t
AVWL
W
16
t
WHDX
21
t
WHQX
SRAM WRITE CYCLE #2: E Controlled
j
12
t
AVAV
ADDRESS
18
t
AVEL
E
14
t
ELEH
19
t
EHAX
17
t
AVEH
W
13
t
WLEH
15
t
DVEH
16
t
EHDX
DATA VALID
HIGH IMPEDANCE
DATA IN
DATA OUT
Document Control #ML0012 Rev 0.3
February 2007
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