Renesas X5045M8IZ

Overview

X5045M8IZ from Intersil is a CPU supervisor IC integrating power-on reset control, watchdog timer, supply voltage supervision, and 4Kbit SPI EEPROM in an 8-lead MSOP package. It provides active-low RESET output, 4.63V ±2.5% VTRIP threshold, selectable watchdog timeout (200ms/600ms/1.4s), and 512 × 8-bit EEPROM with block lock protection - used in industrial process controllers for brownout recovery and firmware parameter storage.

For engineers reviewing the X5045M8IZ datasheet, X5045M8IZ pinout, X5045M8IZ application, or X5045M8IZ equivalent, key selection criteria include verified VTRIP reprogrammability, 3.3MHz SPI interface timing compliance, standby current under 50µA with watchdog enabled, and confirmed 8-lead MSOP thermal performance in -40°C to +85°C operation.

Technical Context

The X5045M8IZ implements a dual-function CS/WDI pin that serves as both chip select and watchdog input, requiring periodic high-to-low transitions to prevent reset assertion. Its internal power-on reset circuit holds RESET low for 100–400ms after VCC exceeds VTRIP, ensuring microcontroller stabilization before code execution.

Voltage supervision uses a precision comparator with factory-trimmed 4.63V ±2.5% trip point, reprogrammable via VP=15–18V on WP pin and WREN+write sequence to address 01h. The EEPROM block lock protection is controlled by nonvolatile BL0/BL1 bits in the status register, enabling selective write protection of 0%, 25%, 50%, or 100% of the 512-byte array.

Key Specifications

Pinout & Package

Package: 8-lead MSOP (3.0mm × 3.0mm × 1.0mm height), RoHS-compliant Pb-free plus anneal finish, MSL3 per J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6361KA29+T and STM8S003F3P6, the X5045M8IZ delivers verified integration of reset, watchdog, and high-endurance EEPROM in a single 8-pin MSOP - reducing component count, eliminating interconnect reliability risks, and guaranteeing factory-trimmed VTRIP accuracy without calibration.

Availability

X5045M8IZ is available at Aetrix Electronics and suitable for industrial process controllers, network infrastructure routers, medical diagnostic equipment, and battery-powered handheld testers requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for X5045M8IZ 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) designs high-reliability analog and mixed-signal ICs for industrial, aerospace, and communications markets, with emphasis on power management and system supervision.

The X5045M8IZ belongs to Intersil's CPU Supervisor family, engineered to consolidate reset generation, watchdog monitoring, voltage supervision, and nonvolatile storage into a single die - targeting space-constrained, safety-critical embedded systems where board area and failure mode coverage are paramount.

FAQ

What is the factory-default VTRIP voltage for the X5045M8IZ?

The X5045M8IZ ships with a factory-trimmed VTRIP of 4.63V ±2.5%, corresponding to the "-4.5A" suffix in its ordering code. This threshold is guaranteed over temperature and time without external components, and can be reprogrammed to custom values using the VP=15–18V method described in the FN8126 datasheet. The X5045M8IZ maintains this setting across power cycles and retains it for 100 years.

Does the X5045M8IZ support active-high reset output?

No, the X5045M8IZ provides only an active-low open-drain RESET output. The datasheet confirms RESET is asserted low during brownout or watchdog timeout, and remains low until VCC exceeds VTRIP for 200ms. For active-high reset requirements, external inversion (e.g., transistor or logic gate) is necessary. The X5045M8IZ does not include an internal active-high variant - that function is implemented in the X5045PZ/X5045S8IZ series with separate RESET pin naming.

How is the watchdog timeout period configured on the X5045M8IZ?

The watchdog timeout on the X5045M8IZ is set via nonvolatile WD0 and WD1 bits in the status register, programmed using the WRSR instruction. Valid combinations yield 200ms (WD1=1, WD0=0), 600ms (WD1=0, WD0=1), or 1.4s (WD1=0, WD0=0); WD1=WD0=1 disables the watchdog. These bits retain their state through power cycles, and the X5045M8IZ defaults to disabled watchdog at power-up per factory setting.

Can the X5045M8IZ EEPROM be written in single-byte mode?

Yes, the X5045M8IZ supports both single-byte and 16-byte page writes to its 512×8 EEPROM array. Page writes require all bytes to reside within the same 16-byte boundary (e.g., addresses 0x00–0x0F), while single-byte writes have no alignment restriction. Each write cycle takes 5ms typical, and the WIP bit in the status register must be polled to confirm completion before issuing subsequent commands. The X5045M8IZ guarantees 1,000,000 write cycles per byte.

What is the maximum junction temperature rating for the X5045M8IZ in MSOP package?

The X5045M8IZ in 8-lead MSOP package is rated for operation from -40°C to +85°C ambient temperature, with absolute maximum junction temperature of +135°C. Thermal resistance θ_JA is 160°C/W (typical), meaning at 5.5V and 3mA active current, power dissipation remains below 17mW - resulting in negligible self-heating. The X5045M8IZ meets industrial temperature requirements without derating or heatsinking in standard PCB layouts.