The GR881 is a non-volatile RAM of 8K×8 released by Greenwich Instruments Ltd. It has good storage characteristics and can be widely used in program development, data collection, process control, automation and robotics, etc.
The GR881 is an 8192‑word by 8‑bit non‑volatile CMOS static RAM fabricated with advanced silicon‑gate technology and a high‑reliability lithium power cell. It conforms to JEDEC pin‑out standards and can retain data indefinitely without external power, making it suitable for program development, data logging, and lookup tables in automation and robotics.
Key specifications include a maximum power‑down time of 15 µs, a typical operating supply voltage of 5 V, data‑retention voltage of 4.5 V, and a ten‑year data‑retention period. The device provides detailed timing parameters such as 100 ns read and write cycles, and includes absolute maximum ratings, pin‑out diagrams, and disposal instructions.
| Memory size | 8192 words × 8 bits (8 K×8) |
|---|---|
| Power‑down time | 15 µs (max) |
| Data retention time | 10 years (typical) |
| Operating supply voltage (Vdd) | 4.75 V – 5.5 V |
| Absolute maximum Vdd | 7.0 V |
| Access time (read cycle) | 100 ns |
| Write cycle time | 100 ns |
| Package dimensions | 37 mm × 73 mm |
The GR881 powers down from 5 V to 0 V in a maximum of 15 µs.
It can retain data for about ten years, limited by the shelf life of its lithium cell.
The device operates typically at 5 V, with a minimum of 4.75 V and a maximum of 5.5 V.
The GR881 provides 8192 words of 8‑bit storage, equivalent to 8 K×8.