Flexible NV SRAM Stik

The DS2227 combines voltage monitoring circuitry with lithium-backed memory in a flexible architecture that can be accessed as 128k x 32, 256k x 16, or 512k x 8 bits.

Using precise comparators, the DS2227 monitors incoming Vcc for an out-or-tolerance condition. When such a condition occurs, the internal lithium energy source is automatically switched on and write protection is unconditionally enabled to prevent data corruption.

While the DS2227 is used like a standard static RAM, it can be flexibly configured by virtue of separate read, write, and chip-select bits for each of the four memory banks.

Dallas' nonvolatile memory chips are known throughout the industry for low-power consumption. They render data nonvolatile for greater than 10 years in the absence of power, greater than the useful like of the associated equipment.

* Memory with flexible architecture:

* 128k x 32

* 256k x 16

* 512k x 8

* NV circuitry transparent to/independent of host

* Automatic write protection circuitry

* Separate chip-enables for access by byte, word, or long word

* Access times: 70ns, 100ns, or 120ns

* Unlimited write cycles

* Equal read/write cycle times

* JEDEC-standard 72-position SIMM connection

* Lithium source with freshness seal

* Operating ranges:

* 5V±10% tolerance

* 0°C to 70°C