Renesas X5323S8T1

Overview

X5323S8T1 from Intersil is a 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 provides active-low reset assertion down to VCC = 1V, selectable watchdog timeout (200ms/600ms/1.4s), five factory-standard VTRIP thresholds (e.g., 4.25–4.5V), and block-lock EEPROM protection. It serves as a system-level reliability manager in microcontroller-based industrial controllers requiring brown-out immunity and nonvolatile configuration storage.

For engineers reviewing the X5323S8T1 datasheet, X5323S8T1 pinout, X5323S8T1 application, or X5323S8T1 equivalent, this device delivers verified low-voltage reset validity, reprogrammable VTRIP threshold, SPI EEPROM endurance (100k cycles), and integrated watchdog flag detection - all critical for embedded systems with strict power sequencing and firmware integrity requirements.

Technical Context

The X5323S8T1 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 active until VCC exceeds the programmed VTRIP threshold for 200ms, with guaranteed operation down to 1V supply.

Internally, it combines a 32kbit (4k × 8) serial EEPROM array with Block Lock™ protection, Direct Write™ memory cells (100-year data retention), and a status register containing volatile WIP/WEL bits plus nonvolatile WD0/WD1, BL0/BL1, and WPEN bits - all accessible via standard SPI opcodes (READ, WRITE, WRSR, RDSR).

Key Specifications

Pinout & Package

Package: 8-lead SOIC (Pb-free, RoHS compliant), body width 3.9mm, 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 STM8S105K4T6C, the X5323S8T1 uniquely combines field-reprogrammable VTRIP, three-tier watchdog timeout, and 32kbit EEPROM in a pin-compatible 8-SOIC footprint - delivering hardware-enforced reliability without MCU resource overhead or fixed-threshold limitations.

Availability

X5323S8T1 is available at Aetrix Electronics and suitable for industrial automation, medical device, and automotive body electronics requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for X5323S8T1 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 X5323S8T1 belongs to Intersil's CPU Supervisor family, designed specifically to consolidate reset, watchdog, voltage monitoring, and nonvolatile storage functions into a single chip - reducing board space and improving system-level reliability in resource-constrained embedded applications.

FAQ

What is the factory-default VTRIP setting for X5323S8T1?

The X5323S8T1 ships with a factory-default VTRIP range of 4.25V to 4.5V (typical 4.38V) for use with +5V supply rails. This threshold is nonvolatile and persists across power cycles unless reprogrammed using the VP-based VTRIP adjustment sequence described in the datasheet.

Does X5323S8T1 support both active-high and active-low reset outputs?

No - the X5323S8T1 provides only an active-low RESET/RESET output. The X5325 variant offers active-high reset; X5323S8T1 is strictly active-low. The output is open-drain and requires an external pull-up resistor to the system reset rail voltage.

How is the watchdog timeout period selected on X5323S8T1?

The watchdog timeout on X5323S8T1 is selected by programming two nonvolatile bits (WD0 and WD1) in the status register via the WRSR instruction. Valid combinations yield 200ms (WD1=1, WD0=0), 600ms (WD1=0, WD0=1), or 1.4s (WD1=0, WD0=0); the watchdog is disabled by default (WD1=1, WD0=1).

Can the EEPROM in X5323S8T1 be protected against accidental writes?

Yes - X5323S8T1 supports multiple hardware and software write protection layers: Power-up/power-down circuitry prevents writes during voltage transients; WP pin + WPEN bit enable in-circuit programmable ROM mode; and BL0/BL1 bits allow nonvolatile block locking of 0%, 25%, 50%, or 100% of the 32kbit array.

What SPI modes does X5323S8T1 support?

X5323S8T1 supports SPI modes 0,0 (CPOL=0, CPHA=0) and 1,1 (CPOL=1, CPHA=1) at up to 2MHz clock rate. Data is always transmitted MSB-first; SI samples on SCK rising edge, SO drives on SCK falling edge - matching common microcontroller SPI peripheral configurations.