The document describes the features and characteristics of the Simtek STK12C68 product, including access times of 25ns to 55ns, automatic storage function, hardware and software initiated storage and recall operations, typical ICC of 10mA, unlimited read, write, and recall cycles, one million store cycles, and one hundred years of data retention. The product is suitable for commercial, industrial, and military temperature environments and is available in 28-pin SOIC, DIP, and LCC packages.
The STK12C68 combines 8 K × 8 SRAM with a non‑volatile element in each cell, allowing unlimited read/write cycles while preserving data after power loss. STORE and RECALL operations can be triggered automatically on power‑down, by hardware, software, or the AutoStore™ feature, and a 68 µF (or larger) capacitor guarantees successful STORE.
The device supports a range of access times (25 ns to 55 ns), operates across commercial, industrial and military temperature ranges, and is offered in 28‑pin SOIC, DIP and LCC packages. It provides 1 000 000 STORE cycles, 100‑year data retention, and typical 10 mA current at 200 ns cycle time.
| Access Time | 25 ns, 35 ns, 45 ns, 55 ns |
|---|---|
| Data Retention | 100 years |
| Endurance (STORE cycles) | 1 000 000 cycles |
| Typical Current | 10 mA at 200 ns cycle time |
| Package Options | 28‑Pin SOIC, DIP and LCC |
| Operating Temperature | Commercial 0‑70 °C, Industrial –40‑85 °C, Military –55‑125 °C |
| Bypass Capacitor Recommendation | ~0.1 µF high‑frequency capacitor |
STORE transfers data from the SRAM array to the non‑volatile elements, and can be initiated automatically on power‑down, by hardware, software, or the AutoStore™ feature.
A capacitor of 68 µF or larger tied from Vcap to ground is required to guarantee the STORE operation regardless of power‑down slew rate.
The input voltage relative to ground may range from –0.5 V to 7.0 V, and the voltage on Vcc may not exceed Vcc + 0.5 V.
A high‑frequency bypass capacitor of about 0.1 µF should be placed between Vcap and Vss with short leads and traces.