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| STK25C48 Datasheet, PDF (1/8 Pages) List of Unclassifed Manufacturers – 2K X 8 AUTOSTORE NVSRAM | |||
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STK25C48
2K x 8 AutoStore⢠nvSRAM
QuantumTrap⢠CMOS
Nonvolatile Static RAM
FEATURES
⢠Nonvolatile Storage without Battery Problems
⢠Directly Replaces 2K x 8 Static RAM, Battery-
Backed RAM or EEPROM
⢠20ns, 25ns, 35ns and 45ns Access Times
⢠STORE to EEPROM Initiated by AutoStoreâ¢
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 EEPROM
⢠100-Year Data Retention over Full Industrial
Temperature Range
⢠Commercial and Industrial Temperatures
⢠24-Pin 600 PDIP Package
DESCRIPTION
The STK25C48 is a fast SRAM with a nonvolatile
EEPROM element incorporated in each static memory
cell. The SRAM can be read and written an unlimited
number of times, while independent nonvolatile data
resides in the EEPROM. Data transfers from the SRAM to
the EEPROM (the STORE operation) can take place auto-
matically on power down using charge stored in system
capacitance. Transfers from the EEPROM to the SRAM
(the RECALL operation) take place automatically on res-
toration of power. The nvSRAM can be used in place of
existing 2K x 8 SRAMs and also matches the pinout of
2K x 8 battery-backed SRAMs, EPROMs and EEPROMs,
allowing direct substitution while enhancing performance.
There is no limit on the number of read or write cycles that
can be executed, and no support circuitry is required for
microprocessor interfacing.
BLOCK DIAGRAM
EEPROM ARRAY
32 x 512
A5
STORE
A6
STATIC RAM
A7
ARRAY
RECALL
A8
32 x 512
A9
STORE/
RECALL
CONTROL
VCC
POWER
CONTROL
DQ0
DQ1
DQ2
COLUMN I/O
COLUMN DEC
DQ3
DQ4
DQ5
DQ6
A0 A1 A2 A3 A4 A10
G
DQ7
E
W
PIN CONFIGURATIONS
A6
A5 1
24 VCC
A4 2
23 A8
A3 3
22 A9
A2 4
A1 5
21 W
20 G
A0 6
19 A10
DQ0 7
DQ1 8
DQ2 9
VSS 10
18 E
17 DQ7
16 DQ6
15 DQ5
11
14 DQ4
12
13 DQ3 24 - 600 PDIP
PIN NAMES
A0 - A10
W
DQ0 - DQ7
E
G
VCC
VSS
Address Inputs
Write Enable
Data In/Out
Chip Enable
Output Enable
Power (+ 5V)
Ground
July 1999
3-31
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