Renesas X5325S8

Overview

X5325S8 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 delivers active-high RESET output, 4.5–4.75V VTRIP threshold, and operates across 0°C to +70°C. Used in microcontroller-based embedded systems requiring reliable power sequencing and nonvolatile configuration storage.

For engineers reviewing the X5325S8 datasheet, X5325S8 pinout, X5325S8 application, or X5325S8 equivalent, this page provides verified functional identity, confirmed pin roles (CS/WDI, SO, SCK, SI, WP, VSS, VCC, RESET/RESET), exact VTRIP programming capability, watchdog timeout options (200ms/600ms/1.4s), and validated alternatives for industrial MCU supervisory designs.

Technical Context

The X5325S8 integrates four co-located functions: a power-on reset generator asserting RESET/RESET down to VCC = 1V, a selectable watchdog timer with nonvolatile WD0/WD1 bits, a low-VCC detector with reprogrammable trip point (4.5–4.75V factory-set), and a 32kbit SPI EEPROM organized as 4k × 8 with Block Lock™ protection. All functions share a unified SPI interface operating at up to 2MHz in modes 0,0 and 1,1.

Its reset logic asserts active-high RESET/RESET during power-up (tPURST = 100–280ms), brown-out (VCC < VTRIP for >200ms), or watchdog timeout (configurable 200ms/600ms/1.4s). The status register includes volatile WIP/WEL bits and nonvolatile BL0/BL1/WD0/WD1/WPEN flags, enabling in-circuit programmable ROM mode when WP is low and WPEN = 1.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with X5325S8, MAX6361KA29+T offers lower integration and inflexible reset voltage, while STM6805RWY6F lacks EEPROM entirely - both require design compromises in footprint, BOM count, or configurability that X5325S8 avoids.

Availability

X5325S8 is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic devices, smart energy meters, and automotive body control modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for X5325S8 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 manufacturer specializing in precision analog, power management, and interface ICs for industrial, computing, and communications markets.

The X5325S8 belongs to Intersil's CPU Supervisor family, designed to reduce system complexity by merging reset, watchdog, voltage monitoring, and nonvolatile memory into a single chip for resource-constrained embedded controllers.

FAQ

What is the reset output polarity of the X5325S8?

The X5325S8 features an active-HIGH RESET/RESET output, distinct from the active-LOW variant X5323S8. This allows direct connection to MCUs requiring high-asserted reset signals without inversion logic. The output is open-drain, so an external pull-up resistor to VCC is required for proper logic-level definition. The X5325S8 asserts RESET/RESET during power-up, brown-out (VCC < VTRIP), or watchdog timeout, holding it active until VCC exceeds VTRIP for 200ms.

Can the VTRIP voltage of the X5325S8 be changed after soldering?

Yes, the X5325S8 supports in-circuit VTRIP reprogramming using a 15–18V pulse applied to SCK and SI pins while holding CS/WDI and WP HIGH. This allows field adjustment of the reset threshold - for example, raising the factory-set 4.5–4.75V range to meet tighter system tolerances. The procedure is nonvolatile and survives power cycles. The X5325S8 datasheet specifies full electrical validation of this function across 0°C to +70°C.

How does the X5325S8 prevent accidental EEPROM writes?

The X5325S8 implements three independent write safeguards: (1) a volatile Write Enable Latch (WEL) that must be set via WREN instruction before each write; (2) nonvolatile Block Lock™ bits (BL0/BL1) protecting 0%, 25%, 50%, or 100% of the 32kbit array; and (3) in-circuit programmable ROM mode activated when WP = LOW and WPEN = 1, which disables all status register writes. These layers ensure robust protection against firmware bugs or ESD-induced corruption in the X5325S8.

What watchdog timeout periods are available on the X5325S8?

The X5325S8 offers three nonvolatile watchdog timeout options: 200ms (WD1=1, WD0=0), 600ms (WD1=0, WD0=1), and 1.4s (WD1=0, WD0=0). These are selected by programming the WD0 and WD1 bits in the status register using the WRSR instruction. The watchdog is factory-disabled (WD1=1, WD0=1), and once configured, the timeout remains fixed across power cycles - no runtime register access is needed to maintain timing consistency in the X5325S8.

Does the X5325S8 support SPI Mode 0,0 and Mode 1,1 only?

Yes, the X5325S8 is specified for SPI Mode 0,0 (CPOL=0, CPHA=0) and Mode 1,1 (CPOL=1, CPHA=1) only. In Mode 0,0, data is sampled on the rising edge of SCK and shifted out on the falling edge; in Mode 1,1, sampling occurs on the falling edge and shifting on the rising edge. The X5325S8 does not support Mode 0,1 or Mode 1,0 - MCU SPI peripherals must be configured accordingly to ensure reliable communication with the X5325S8.