Document
STK11C68
8K x 8 nvSRAM QuantumTrap™ CMOS Nonvolatile Static RAM
FEATURES
• 20ns, 25ns, 35ns and 45ns Access Times • STORE to EEPROM Initiated by Software • 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 • 28-Pin DIP and SOIC Packages
DESCRIPTION
The Simtek STK11C68 is a fast static RAM with a nonvolatile, electrically erasable PROM 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), or from EEPROM to SRAM (the RECALL operation), take place using a software sequence. Transfers from the EEPROM to the SRAM (the RECALL operation) also take place automatically on restoration of power. The STK11C68 is pin-compatible with industrystandard SRAMs. MIL-STD-883 device is also available (STK11C68-M).
BLOCK DIAGRAM
EEPROM ARRAY 128 x 512
PIN CONFIGURATIONS
NC 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
A5
ROW DECODER
A6 A7 A8 A9 A11 A12
DQ0 DQ1 DQ2 DQ3 DQ4 DQ5 DQ6 DQ7
STORE STATIC RAM ARRAY 128 x 512 RECALL
STORE/ RECALL CONTROL
SOFTWARE DETECT INPUT BUFFERS COLUMN I/O COLUMN DEC
A0 - A12
VCC W NC A8 A9 A11 G A10 E DQ7 DQ6 DQ5 DQ4 DQ3
28 - 300 PDIP 28 - 300 CDIP 28 - 350 SOIC
PIN NAMES
A0 - A12 Address Inputs Write Enable Data In/Out Chip Enable Output Enable Power (+ 5V) Ground W
A0 A1 A2 A3 A4 A10
G E W
DQ0 - DQ7 E G VCC VSS
June 1999
4-21
STK11C68
ABSOLUTE MAXIMUM RATINGSa
Voltage on Input Relative to VSS . . . . . . . . . . –0.6V to (VCC + 0.5V) Voltage on DQ0-7 . . . . . . . . . . . . . . . . . . . . . . –0.5V to (VCC + 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 conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.
DC CHARACTERISTICS
COMMERCIAL SYMBOL ICC1c PARAMETER MIN Average VCC Current MAX 100 90 75 65 3 10 32 27 23 20 750 ±1 ±5 2.2 VSS – .5 2.4 0.4 0 70 –40 VCC + .5 0.8 2.2 VSS – .5 2.4 0.4 85 MIN MAX N/A 90 75 65 3 10 N/A 28 24 21 750 ±1 ±5 VCC + .5 0.8 mA mA mA mA mA mA mA mA mA mA µA µA µA V V V V °C INDUSTRIAL UNITS
(VCC = 5.0V ± 10%)b
NOTES .