This document is the specification for GR281 (2K x 8) non-volatile RAM.
The GR281 is a 2048‑word by 8‑bit (2K × 8) non‑volatile CMOS static RAM fabricated with advanced silicon‑gate CMOS technology and a high‑reliability lithium power cell. Its pin‑out conforms to JEDEC standards and it includes an automatic power‑down circuit referenced at 4.5 V, providing fast power‑down in 15 µs and data protection via an internal inhibit function.
The device is suitable for data‑loggers, process‑control, automation, robotics and user‑definable lookup tables. It can retain data indefinitely without external power, limited mainly by the lithium cell’s shelf life of about ten years. Disposal must follow the provided instructions, returning the device to Greenwich Instruments for proper handling.
| Operating supply voltage (typical) | 5.0 V |
|---|---|
| Absolute maximum Vdd | -0.3 V to 7.0 V |
| Operating temperature range | -20 °C to +70 °C |
| Power‑down time | 15 µs |
| Data retention time | 10 years |
| Active supply current | 25 mA |
The GR281 powers down in a maximum of 15 µs from 5 V to 0 V.
Data can be retained for up to ten years, limited by the lithium cell’s shelf life.
Vdd may be as low as –0.3 V and as high as 7.0 V.
Do not incinerate or crush the device; return it carriage‑paid to Greenwich Instruments Ltd.