0
Rating |
Catalog |
Features |
4-Bank SRAM, CMOS, Non-volatile controller, Write-protection |
Operating current (typ) (µA) |
3000 |
Vin (max) (V) |
5.5 |
Operating temperature range (°C) |
-40 to 85 |
PDIP (N)-16-181.42 mm² 19.3 x 9.4
The CMOS bq2204A SRAM Non-volatile Controller Unit provides all necessary functions for converting up to four banks of standard CMOS SRAM into nonvolatile read/write memory.
A precision comparator monitors the 5V VCC input for an out-of-tolerance condi-tion. When out-of-tolerance is detected, the four conditioned chip-enable outputs are forced inactive to write-protect up to four banks of SRAM.
During a power failure, the external SRAMs are switched from the VCC supply to one of two 3V backup sup-plies. On a subsequent power-up, the SRAMs are write-protected until a power-valid condition exists.
During power-valid operation, a two-input decoder transparently selects one of up to four banks of SRAM.