STK15C68
8K x 8 AutoStore™ nvSRAM
QuantumTrap™ CMOS
Nonvolatile Static RAM
Obsolete - Not Recommend for new Deisgns
FEATURES
DESCRIPTION
• Nonvolatile Storage without Battery Problems
• Directly Replaces 8K x 8 Static RAM, Battery-
Backed RAM or EEPROM
• 25ns, 35ns and 45ns Access Times
• STORE to Nonvolatile Elements Initiated by
Software or AutoStore™ on Power Down
• RECALL to SRAM Initiated by Software or
Power Restore
• 10mA Typical ICC at 200ns Cycle Time
• Unlimited READ, WRITE and RECALL Cycles
• 1,000,000 STORE Cycles to Nonvolatile Ele-
ments
• 100-Year Data Retention over Full Industrial
Temperature Range
• No Data Loss from Undershoot
• Commercial and Industrial Temperatures
• 28-Pin 600 or 300 mil PDIP and 350 mil SOIC
Packages
The STK15C68 is a fast SRAM with a nonvolatile ele-
ment incorporated in each static memory cell. The
SRAM can be read and written an unlimited number of
times, while independent nonvolatile data resides in
Nonvolatile Elements. Data transfers from the SRAM to
the Nonvolatile Elements (the STORE operation) can
take place automatically on power down using charge
stored in system capacitance. Transfers from the Non-
volatile Elements to the SRAM (the RECALL operation)
take place automatically on restoration of power. Initia-
tion of STORE and RECALL cycles can also be con-
trolled by entering control sequences on the SRAM
inputs. The STK15C68 is pin-compatible with 8k x 8
SRAMs and battery-backed SRAMs, allowing direct
substitution while enhancing performance. A similar
device (STK16C68) with an internally integrated
capacitor is available for systems with very fast slew
rates. The STK12C68, which uses an external capaci-
tor, is an alternative for these applications.
PIN CONFIGURATIONS
BLOCK DIAGRAM
1
NC
28
27
26
25
24
23
22
21
20
V
CC
W
NC
2
A
A
A
A
A
A
A
A
A
12
QUANTUM TRAP
128 x 512
3
7
6
5
4
3
VCC
4
A
A
A
8
A5
5
9
6
11
STORE
RECALL
A6
STORE/
RECALL
CONTROL
7
G
A
POWER
CONTROL
8
A7
2
10
STATIC RAM
ARRAY
9
E
1
0
A8
10
11
12
13
14
19
18
17
16
15
DQ
DQ
DQ
7
6
128 x 512
DQ
DQ
DQ
0
A9
1
2
5
28 - 300 PDIP
28 - 600 PDIP
28 - 350 SOIC
A11
A12
DQ
DQ
4
3
V
SS
SOFTWARE
DETECT
A0 - A12
DQ0
DQ1
DQ2
DQ3
DQ4
DQ5
DQ6
DQ7
COLUMN I/O
PIN NAMES
COLUMN DEC
A
- A
12
Address Inputs
Write Enable
Data In/Out
Chip Enable
Output Enable
Power (+ 5V)
Ground
0
W
DQ - DQ
0
7
A0 A1 A2 A3 A4 A10
G
E
G
E
V
W
CC
V
SS
March 2006
1
Document Control # ML0009 rev 0.2
SIMTEK [ SIMTEK CORPORATION ]
