Renesas X5325S8IZ

Overview

X5325S8IZ from Intersil is a CPU supervisor IC with integrated 32kbit SPI EEPROM, combining power-on reset control, watchdog timer, supply voltage supervision, and block-lock protected memory in a single 8-lead SOIC package. It operates across 4.5V–5.5V supply, features factory-programmed 4.5V–4.75V reset threshold, supports -40°C to +85°C industrial temperature range, and delivers active-low RESET output with 200ms timeout.

For engineers reviewing the X5325S8IZ datasheet, X5325S8IZ pinout, X5325S8IZ application, or X5325S8IZ equivalent, this device serves as a system-level reliability enhancer for microcontroller-based embedded systems requiring deterministic power sequencing, brown-out protection, fail-safe watchdog recovery, and nonvolatile configuration storage with hardware write lock.

Technical Context

The X5325S8IZ implements a dual-function CS/WDI pin that enables both SPI command selection and watchdog timer restart via HIGH-to-LOW transitions. Its reset logic asserts RESET/RESET at VCC ≈ 1V on power-up and holds it active until VCC exceeds the programmed trip point (4.5V–4.75V) for 200ms.

Watchdog timeout is set by nonvolatile WD0/WD1 bits (factory default disabled), offering three fixed intervals: 200ms, 600ms, or 1.4s. The device integrates a 32kbit (4k × 8) EEPROM array with page-write capability (32-byte pages), self-timed 10ms write cycles, and Block Lock™ protection configurable to 0%, 25%, 50%, or 100% of memory.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (Pb-free, RoHS compliant), body size 3.9mm × 4.9mm, pitch 1.27mm.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar CPU supervisor with EEPROM applications.

Compared with MAX6361KA29+T and STM8AF6266TCY, the X5325S8IZ uniquely combines field-adjustable VTRIP, hardware watchdog with three timeout options, and 32kbit block-locked EEPROM in a single chip-enabling robust, zero-software-dependency supervision for 5V industrial and automotive designs.

Availability

X5325S8IZ is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic devices, automotive body control modules, and smart energy meters requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for X5325S8IZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Intersil (now part of Renesas Electronics) is a semiconductor company specializing in high-performance analog and mixed-signal ICs for power management, precision analog, and timing applications.

The X5325S8IZ belongs to Intersil's CPU Supervisor family, designed specifically to reduce system-level complexity by integrating reset, watchdog, voltage monitoring, and nonvolatile memory into one die-targeting cost-sensitive, reliability-critical embedded systems.

FAQ

What is the factory-default reset threshold voltage for X5325S8IZ?

The X5325S8IZ is ordered as X5325S8IZ-4.5A, indicating a factory-programmed VTRIP range of 4.5V to 4.75V (typical 4.63V). This threshold is set during final test and remains fixed unless reprogrammed using the VP-based VTRIP adjustment procedure described in the FN8131 datasheet. No user configuration is required to use this default setting.

Does X5325S8IZ support both active-high and active-low reset outputs?

No - the X5325S8IZ provides an active-low RESET/RESET output only. The "X5325" designation explicitly identifies the active-high variant (X5323 = active-low, X5325 = active-high). However, the X5325S8IZ part number corresponds to the active-high version: its RESET/RESET pin asserts HIGH during fault conditions. This is confirmed in the Ordering Information table on page 2 of FN8131 Rev 3.00.

How is the watchdog timer enabled and configured on X5325S8IZ?

The watchdog timer on X5325S8IZ is disabled at power-up (WD1=1, WD0=1). To enable it, the host microcontroller must issue a WRSR instruction to write WD1/WD0 bits in the status register. Valid combinations are: 00 = 1.4s, 01 = 600ms, 10 = 200ms. Once written, these bits persist across power cycles unless rewritten or locked via WP/WPEN.

Can the EEPROM in X5325S8IZ be written while the watchdog is running?

Yes - the EEPROM and watchdog functions operate independently. Writing to EEPROM does not interfere with watchdog timing, and the watchdog continues monitoring CS/WDI transitions during active memory writes. However, the CS/WDI pin must still receive a HIGH-to-LOW transition within the selected timeout period to prevent reset assertion, regardless of EEPROM activity.

What is the minimum VCC level at which X5325S8IZ guarantees RESET/RESET assertion?

The X5325S8IZ asserts RESET/RESET down to VCC = 1V, as specified in the "Reset signal valid to VCC = 1V" feature list (page 1) and confirmed in the Absolute Maximum Ratings table (page 10). This ensures reliable reset hold during deep brown-out or battery-depletion scenarios where supply may collapse below nominal thresholds.