The DS1284/DS1286 watchdog timekeepers are self-contained real-time clocks, alarms, watchdog timers, and interval timers in a 28-pin JEDEC DIP and encapsulated DIP package
The DS1284 and DS1286 are self‑contained watchdog timekeepers that combine a real‑time clock, alarm, watchdog timer, and interval timer in a 28‑pin JEDEC package. The DS1286 includes an embedded lithium energy cell, while the DS1284 requires an external crystal and battery. Both devices maintain time and data for over ten years without power and support 24‑hour or 12‑hour formats with AM/PM indication.
Key features include 64 individually addressable 8‑bit registers, 50 bytes of user non‑volatile RAM, programmable interrupts, square‑wave outputs, and operation over an industrial temperature range of –40 °C to +85 °C. Pin descriptions, timing diagrams, and command register functions are provided for system integration.
| Number of registers | 64 8‑bit registers |
|---|---|
| User non‑volatile RAM | 50 bytes |
| Operating temperature range | –40 °C to +85 °C |
| Accuracy | Better than +1 minute/month at +25 °C |
| Battery‑backed timekeeping | Over 10 years without power |
The device provides 50 bytes of user non‑volatile RAM.
The devices operate from –40 °C to +85 °C.
It can maintain time and data for over ten years in the absence of Vcc.