This document describes the features of a programmable watchdog timer and serial E2PROM memory from Xicor, Inc. The product features include a programmable watchdog timer, Block LockTM protection for saving critical data, low power consumption, and high reliability.
The Xicor X25644/46, X25324/26 and X25164/66 devices combine a programmable watchdog timer with a serial E7‑PROM memory array. They provide independent reset protection for microcontrollers and non‑volatile data storage, featuring block‑lock protection, low standby current, and a 2 MHz SPI interface.
The datasheet details pin functions, operation principles, instruction set, timing diagrams, electrical ratings, package options, and ordering information, enabling designers to integrate the devices into low‑power, space‑constrained systems.
| Memory size (X25644/46) | 64 K (8 K × 8 bit) |
|---|---|
| Memory size (X25324/26) | 32 K (4 K × 8 bit) |
| Memory size (X25164/66) | 16 K (2 K × 8 bit) |
| Supply voltage ranges | 1.8 V‑3.6 V, 2.7 V‑5.5 V, 4.5 V‑5.5 V |
| Standby current (watchdog on) | < 50 µA |
| Standby current (watchdog off) | < 1 µA |
| Active write current | < 5 mA |
| Active read current | < 400 µA |
| Clock rate | 2 MHz |
| Available packages | 14‑Lead SOIC, 14‑Lead TSSOP, 8‑Lead SOIC |
| Operating temperature range | Commercial 0 °C‑70 °C, Industrial 40 °C‑85 °C |
| Endurance (write cycles) | ≥ 100 000 cycles per sector |
| Data retention | ≥ 100 years |
The standby current is less than 50 µA with the watchdog timer enabled.
It operates from 1.8 V to 3.6 V, 2.7 V to 5.5 V, or 4.5 V to 5.5 V depending on the part variant.
The device contains an 8‑bit instruction register.