CPU Supervisor with 32kBit SPI EEPROM

Category: Electronics, Intersil Corporation, Other Semiconductors

Introduction

The Intersil X5323 and X5325 devices serve as CPU supervisors that incorporate a 32kBit SPI EEPROM. These parts replace the older models X25323 and X25325, offering a multi-functional solution that simplifies design and enhances system reliability. Features include Power-on Reset Control, Watchdog Timer, Supply Voltage Supervision, and Block Lock Protect Serial EEPROM Memory.

Functionality

When power is applied, the integrated Power-on Reset Control holds the RESET/RESET signals active, allowing the system’s power supply and oscillator time to stabilize. The Watchdog Timer prevents system failure by signaling a microcontroller to restart within a predetermined window. Failing to do so results in an activation of the RESET/RESET signals. Users can select the timeout interval from three preset values that remain consistent even after power cycling.

The Low Vcc detection feature ensures system reset when the supply voltage drops below a certain threshold, maintaining the reset state until the voltage is sufficiently stable and within the proper operating range. Standard voltage thresholds are available, and the device also provides the flexibility to reprogram the threshold to meet custom specifications for higher-precision applications.

Features

Selectable Watchdog Timer interval for system protection.
Low Vcc detection ensures system reset under low-voltage conditions, with five standard reset threshold voltages and the ability to re-program to custom specifications.
RESET signal is maintained even at low voltages down to 1V.
Low power consumption enhances battery life with standby currents as low as <1uA without Watchdog and <40uA during active EEPROM read operations.
32kBits of EEPROM with built-in write protection to prevent inadvertent data changes, featuring Block Lock protection that secures different portions of the EEPROM array.
In-circuit programmable ROM mode with a fast 2MHz SPI interface supporting modes (0,0) and (1,1).
Efficient EEPROM programming with a 32-byte page write mode and 5ms typical write cycle time.
Support for 2.7V to 5.5V and 4.5V to 5.5V power supplies, provided in various Pb-free (RoHS compliant) package options such as 14 Ld TSSOP, 8 Ld SOIC, and 8 Ld PDIP.

Block Diagram Overview

The provided block diagram within the datasheet illustrates the main components which include the Watchdog Timer, Transition Detector, Protect Logic, RESET/RESET outputs, Data and Status Registers, Command Decode and Control Logic, Reset and Watchdog Timebase, Vcc Threshold Reset Logic, and Power-on and Low Voltage Reset Generator. It differentiates between the X5323 and X5325 via the type of reset signal.

Caution

Attention is drawn to the sensitivity of the X5323 and X5325 devices to electrostatic discharge, and users are recommended to follow proper Integrated Circuit Handling Procedures.