Renesas X5325S8I-4.5A

Overview

X5325S8I-4.5A from Intersil is an active-high CPU supervisor IC integrating power-on reset control, watchdog timer, supply voltage supervision, and 32kbit SPI EEPROM in a single 8-lead SOIC package. It operates from 4.5V to 5.5V, features a factory-programmed 4.5V–4.75V reset threshold, supports 2MHz SPI communication, and delivers <1µA standby current with watchdog disabled. It is used in microcontroller-based embedded systems requiring reliable power sequencing and nonvolatile configuration storage.

For engineers reviewing the X5325S8I-4.5A datasheet, X5325S8I-4.5A pinout, X5325S8I-4.5A application, or X5325S8I-4.5A equivalent, this page provides verified technical context, exact pin functions, real-world use cases, and validated alternative parts - all grounded in the FN8131 Rev 3.00 datasheet and Intersil's official specifications for the X5325S8I-4.5A variant.

Technical Context

The X5325S8I-4.5A implements a dual-function CS/WDI pin that serves as both chip select and watchdog input, with a HIGH-to-LOW transition required to reset the watchdog timer. Its reset output (RESET/RESET) is active-high and remains asserted until VCC exceeds the 4.5V–4.75V trip point for 200ms after power-up or brown-out recovery.

Internally, it combines a precision low-VCC detection circuit with a nonvolatile status register containing programmable watchdog timeout bits (WD1/WD0), block lock protection bits (BL1/BL0), and a write-protect enable bit (WPEN). The 32kbit EEPROM array is organized as 4k × 8, supports 32-byte page writes, and guarantees 100,000 write cycles and 100-year data retention using Intersil's Direct Write™ cell technology.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (Pb-free, RoHS compliant), body width 3.9mm, standard JEDEC MS-012AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6361KA29+T and STM8AF5268TCX, the X5325S8I-4.5A delivers a purpose-built, drop-in supervisor with field-adjustable reset threshold and guaranteed EEPROM endurance - eliminating firmware dependencies and supporting immediate deployment in 5V industrial systems.

Availability

X5325S8I-4.5A is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic devices, smart energy meters, automotive body control modules, and embedded instrumentation requiring stable component supply and long-term lifecycle support.

Supply support for X5325S8I-4.5A 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 precision analog, power management, and interface ICs for industrial, computing, and communications markets.

The X5325 product line was designed to consolidate power supervision, watchdog safety, and nonvolatile storage into one die - targeting cost-sensitive, space-constrained embedded systems needing high reliability without software overhead.

FAQ

What is the reset polarity and assertion condition for the X5325S8I-4.5A?

The X5325S8I-4.5A features an active-high RESET/RESET output. It asserts (goes HIGH) when VCC falls below the programmed 4.5V–4.75V trip point or when the watchdog timer expires, and remains asserted until VCC rises above the trip point and stabilizes for 200ms. This behavior is confirmed in the FN8131 datasheet Section "Pin Descriptions" and "Principles of Operation".

Does the X5325S8I-4.5A support in-circuit reprogramming of its VTRIP voltage?

Yes, the X5325S8I-4.5A supports in-circuit VTRIP reprogramming using a dedicated VP pulse sequence applied to SCK and SI pins while holding CS/WDI and WP HIGH. The procedure allows increasing the threshold to a higher value (e.g., from 4.5V to 4.65V) and is fully documented in FN8131 Pages 4–5 and Figure 1. It does not support lowering VTRIP without first executing a reset sequence.

How much EEPROM memory does the X5325S8I-4.5A provide, and what is its endurance?

The X5325S8I-4.5A integrates 32kbit (4,096 × 8) of serial EEPROM memory using Intersil's Direct Write™ cell technology. It guarantees a minimum of 100,000 write/erase cycles and 100 years of data retention at +25°C, as specified in FN8131 Page 6. Memory is accessed via standard SPI commands including READ, WRITE, and WRSR.

What are the watchdog timeout options available on the X5325S8I-4.5A?

The X5325S8I-4.5A offers three selectable watchdog timeout periods: 200ms (WD1=1, WD0=0), 600ms (WD1=0, WD0=1), and 1.4s (WD1=0, WD0=0), as defined in the status register (Table on FN8131 Page 7). The watchdog is factory-disabled (WD1=1, WD0=1) and must be enabled via WRSR command before use.

Is the X5325S8I-4.5A RoHS compliant and qualified for lead-free reflow?

Yes, the X5325S8I-4.5A is Pb-free and RoHS compliant, featuring 100% matte tin e3 termination. It is rated for MSL3 per IPC/JEDEC J-STD-020 and qualified for Pb-free reflow soldering, as stated in the "Ordering Information" section (Page 2) and "Thermal Information" (Page 10) of FN8131 Rev 3.00.