STK22C48
2K x 8
AutoStore™
nvSRAM
QuantumTrap™
CMOS
Nonvolatile Static RAM
FEATURES
• 25ns, 35ns and 45ns Access Times
• “Hands-off” Automatic
STORE
with External
68µF Capacitor on Power Down
•
STORE
to Nonvolatile Elements Initiated by
Hardware or
AutoStore™
on Power Down
• Automatic
RECALL
on Power Up
• 10mA Typical I
CC
at 200ns Cycle Time
• Unlimited READ, WRITE and
RECALL
Cycles
• 1,000,000
STORE
Cycles to Nonvolatile Ele-
ments
• 100-Year Data Retention in Nonvolatile Ele-
ments
• Single 5V + 10% Operation
• Commercial and Industrial Temperatures
• 28-Pin DIP and SOIC Packages
DESCRIPTION
The Simtek STK22C48 is a fast static
RAM
with a
nonvolatile element incorporated in each static
memory cell. The
SRAM
can be read and written an
unlimited number of times, while independent, non-
volatile data resides in Nonvolatile Elements. Data
transfers from the
SRAM
to the Nonvolatile Elements
(the
STORE
operation) can take place automatically
on power down. A 68µF or larger capacitor tied from
V
CAP
to ground guarantees the
STORE
operation,
regardless of power-down slew rate or loss of power
from “hot swapping”. Transfers from the Nonvolatile
Elements to the
SRAM
(the
RECALL
operation) take
place automatically on restoration of power. A hard-
ware
STORE
may be initiated with the HSB pin.
BLOCK DIAGRAM
V
CCX
V
CAP
POWER
CONTROL
PIN CONFIGURATIONS
V
CAP
NC
A
7
A
6
A
5
A
4
A
3
A
2
A
1
A
0
DQ
0
DQ
1
DQ
2
V
SS
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
Quantum Trap
32 x 512
ROW DECODER
A
5
A
6
A
7
A
8
A
9
STORE
STATIC RAM
ARRAY
32 x 512
RECALL
STORE/
RECALL
CONTROL
HSB
V
CCX
W
HSB
A
8
A
9
NC
G
A
10
E
DQ
7
DQ
6
DQ
5
DQ
4
DQ
3
28 - 300 PDIP
28 - 600 PDIP
28 - 300 SOIC
28 - 350 SOIC
DQ
0
DQ
1
DQ
2
DQ
3
DQ
4
DQ
5
DQ
6
DQ
7
INPUT BUFFERS
COLUMN I/O
COLUMN DEC
PIN NAMES
A
0
- A
10
DQ
0
-DQ
7
E
W
Address Inputs
Data In/Out
Chip Enable
Write Enable
Output Enable
Hardware Store Busy (I/O)
Power (+ 5V)
Capacitor
Ground
A
0
A
1
A
2
A
3
A
4
A
10
G
E
W
G
HSB
V
CCX
V
CAP
V
SS
September 2003
1
Document Control # ML0004 rev 0.1
STK22C48
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
or HSB . . . . . . . . . . . . . . . .–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 con-
ditions 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
SYMBOL
I
CC b
1
(V
CC
= 5.0V
±
10%)
e
INDUSTRIAL
MIN
MAX
90
75
65
3
10
2
26
22
19
1.5
±1
±5
2.2
V
SS
– .5
2.4
V
CC
+ .5
0.8
UNITS
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
µA
µA
V
V
V
0.4
0.4
–40
85
V
V
°C
t
AVAV
= 25ns
t
AVAV
= 35ns
t
AVAV
= 45ns
All Inputs Don’t Care, V
CC
= max
W
≥
(V
CC
– 0.2V)
All Others Cycling, CMOS Levels
All Inputs Don’t Care
t
AVAV
= 25ns, E
≥
V
IH
t
AVAV
= 35ns, 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 except HSB
I
OUT
= 8mA except HSB
I
OUT
= 3mA
NOTES
PARAMETER
Average V
CC
Current
COMMERCIAL
MIN
MAX
85
75
65
3
10
2
25
21
18
1.5
±1
±5
2.2
V
SS
– .5
2.4
0.4
0.4
0
70
V
CC
+ .5
0.8
I
CC c
2
3
Average V
CC
Current during
STORE
Average V
CC
Current at t
AVAV
= 200ns
5V, 25°C, Typical
Average V
CAP
Current during
AutoStore™
Cycle
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
Logic “0” Voltage on HSB Output
Operating Temperature
I
CC
b
I
CC c
4
I
SB d
1
I
SB d
2
I
ILK
I
OLK
V
IH
V
IL
V
OH
V
OL
V
BL
T
A
Note b:
Note c:
Note d:
Note e:
I
CC
and I
CC
are dependent on output loading and cycle rate. The specified values are obtained with outputs unloaded.
1
3
I
CC
and I
CC
are the average currents required for the duration of the respective
STORE
cycles (t
STORE
) .
2
4
E
≥
V
IH
will not produce standby current levels until any nonvolatile cycle in progress has timed out.
V
CC
reference levels throughout this datasheet refer to V
CCX
if that is where the power supply connection is made, or V
CAP
if V
CCX
is con-
nected to ground.
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
480 Ohms
OUTPUT
255 Ohms
30 pF
INCLUDING
SCOPE AND
FIXTURE
CAPACITANCE
f
SYMBOL
C
IN
C
OUT
PARAMETER
Input Capacitance
Output Capacitance
(T
A
= 25°C, f = 1.0MHz)
MAX
8
7
UNITS
pF
pF
CONDITIONS
∆V
= 0 to 3V
∆V
= 0 to 3V
Note f:
These parameters are guaranteed but not tested.
Figure 1
:
AC Output Loading
September 2003
2
Document Control # ML0004 rev 0.1
STK22C48
SRAM READ CYCLES #1 & #2
NO.
1
2
3
4
5
6
7
8
9
10
11
SYMBOLS
#1, #2
t
ELQV
t
AVAVg
t
AVQVh
t
GLQV
t
AXQXh
t
ELQX
t
EHQZ
i
(V
CC
= 5.0V
±
10%)
e
PARAMETER
STK22C48-25
MIN
MAX
25
25
25
10
5
5
10
0
10
0
25
0
35
0
13
0
45
5
5
13
0
15
35
35
15
5
5
15
STK22C48-35
MIN
MAX
35
45
45
20
STK22C48-45
MIN
MAX
45
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Alt.
t
ACS
t
RC
t
AA
t
OE
t
OH
t
LZ
t
HZ
t
OLZ
t
OHZ
f
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
t
GLQX
t
GHQZi
t
ELICCH
t
EHICCLf
t
PA
t
PS
Note g: W and HSB must be high during SRAM READ cycles.
Note h: Device is continuously selected with E and G both low.
Note i: Measured
±
200mV from steady state output voltage.
SRAM READ CYCLE #1:
Address Controlled
g, h
2
t
AVAV
ADDRESS
5
3
t
AVQV
DATA VALID
t
AXQX
DQ (DATA OUT)
SRAM READ CYCLE #2:
E Controlled
g
t
AVAV
ADDRESS
t
ELQV
E
t
ELQX
t
EHQZ
7
6
1
1
1
2
t
EHICCL
G
t
GLQV
4
t
GHQZ
9
t
GLQX
DQ (DATA OUT)
10
t
ELICCH
ACTIVE
DATA VALID
8
I
CC
STANDBY
September 2003
3
Document Control # ML0004 rev 0.1
STK22C48
SRAM WRITE CYCLES #1 & #2
NO.
12
13
14
15
16
17
18
19
20
21
SYMBOLS
#1
t
AVAV
t
WLWH
t
ELWH
t
DVWH
t
WHDX
t
AVWH
t
AVWL
t
WHAX
t
WLQZ i, j
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
STK22C48-25
MIN
25
20
20
10
0
20
0
0
10
5
MAX
(V
CC
= 5.0V
±
10%)
e
STK22C48-35
MIN
35
25
25
12
0
25
0
0
13
5
MAX
STK22C48-45
MIN
45
30
30
15
0
30
0
0
15
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Note j: If W is low when E goes low, the outputs remain in the high-impedance state.
Note k: E or W must be
≥
V
IH
during address transitions.
Note l: HSB must be high during SRAM WRITE cycles.
SRAM WRITE CYCLE #1:
W Controlled
k, l
12
t
AVAV
ADDRESS
14
t
ELWH
E
17
t
AVWH
13
t
WLWH
15
t
DVWH
DATA IN
20
t
WLQZ
PREVIOUS DATA
DATA VALID
19
t
WHAX
18
t
AVWL
W
16
t
WHDX
DATA OUT
HIGH IMPEDANCE
21
t
WHQX
SRAM WRITE CYCLE #2:
E Controlled
k, l
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
September 2003
4
Document Control # ML0004 rev 0.1
STK22C48
HARDWARE MODE SELECTION
E
H
L
L
X
W
X
H
L
X
HSB
H
H
H
L
A
12
- A
0
(hex)
X
X
X
X
MODE
Not Selected
Read SRAM
Write SRAM
Nonvolatile
STORE
I/O
Output High Z
Output Data
Input Data
Output High Z
POWER
Standby
Active
Active
l
CC
2
NOTES
n
m
Note m: HSB
STORE
operation occurs only if an SRAM write has been done since the last nonvolatile cycle. After the
STORE
(if any) completes, the
part will go into standby mode, inhibiting all operations until HSB rises.
Note n: I/O state assumes G < V
IL
. Activation of nonvolatile cycles does not depend on state of G.
HARDWARE
STORE
CYCLE
NO.
22
23
24
25
26
SYMBOLS
Standard
t
STORE
t
DELAY
t
RECOVER
t
HLHX
t
HLBL
Alternate
t
HLHZ
t
HLQZ
t
HHQX
STORE
Cycle Duration
Time Allowed to Complete SRAM Cycle
Hardware
STORE
High to Inhibit Off
Hardware
STORE
Pulse Width
Hardware
STORE
Low to Store Busy
PARAMETER
(V
CC
= 5.0V
±
10%)
e
STK22C48
MIN
MAX
10
1
700
15
300
UNITS NOTES
ms
µs
ns
ns
ns
i, o
i, p
o, q
Note o: E and G low for output behavior.
Note p: E and G low and W high for output behavior.
Note q: t
RECOVER
is only applicable after t
STORE
is complete.
HARDWARE
STORE
CYCLE
25
t
HLHX
HSB (IN)
24
t
RECOVER
22
t
STORE
HSB (OUT)
26
t
HLBL
HIGH IMPEDANCE
HIGH IMPEDANCE
23
t
DELAY
DQ (DATA OUT)
DATA VALID
DATA VALID
September 2003
5
Document Control # ML0004 rev 0.1
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