Renesas X5045S8I-4.5A

Overview

X5045S8I-4.5A from Intersil (now Renesas) is a 4K-bit SPI EEPROM with integrated CPU supervisor functions including power-on reset, watchdog timer, and programmable voltage monitoring. It features 4.63V ±2.5% reset threshold, 3.3MHz SPI interface, 512 × 8-bit memory organization, and block-lock protection - deployed in industrial process controllers to ensure deterministic boot sequencing and nonvolatile parameter retention during brownout events.

For engineers reviewing the X5045S8I-4.5A datasheet, X5045S8I-4.5A pinout, X5045S8I-4.5A application, or X5045S8I-4.5A equivalent, key selection criteria include its active-high RESET output, -40°C to +85°C operating range, SOIC-8 package compatibility, and reprogrammable VTRIP capability for precision supply supervision in embedded control systems.

Technical Context

The X5045S8I-4.5A implements a dual-function architecture: a 4K-bit SPI EEPROM with Direct Write™ cell technology (1M write cycles, 100-year data retention) co-integrated with analog voltage detection, digital watchdog timing, and POR logic. Its reset assertion is triggered by VCC falling below 4.63V ±2.5% or by watchdog timeout on CS/WDI pin, with reset release delayed 200ms after VCC recovery.

Watchdog timeout is set via nonvolatile WD0/WD1 bits in the status register (default: disabled), and voltage trip point can be reprogrammed using 15–18V on WP with specific WREN + write sequences - enabling field calibration without hardware change. The device operates across 4.5–5.5V supply and supports 16-byte page writes with 5ms typical write cycle time.

Key Specifications

Pinout & Package

Package: 8-pin SOIC (Small Outline Integrated Circuit), RoHS-compliant, Pb-free plus anneal finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6816ESE+, X5045S8I-4.5A integrates memory and supervision in one die, reducing layout complexity and interconnect risk; compared with MCP9808-E/SN, it delivers deterministic system-level reliability rather than environmental measurement - making it irreplaceable for boot-critical supervision tasks.

Availability

X5045S8I-4.5A is available at Aetrix Electronics and suitable for industrial process controllers, network infrastructure equipment, medical diagnostic instruments, and smart energy meters requiring stable component supply across extended product lifecycles.

Supply support for X5045S8I-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 (acquired by Renesas Electronics in 2017) is a semiconductor company specializing in power management, precision analog, and interface ICs for industrial, communications, and computing markets.

The X5045 family was designed to consolidate power supervision, watchdog safety, and nonvolatile storage into a single SPI-compatible device - targeting cost-sensitive, space-constrained embedded systems where reliability and field-programmable thresholds are essential.

FAQ

What is the reset output polarity of the X5045S8I-4.5A?

The X5045S8I-4.5A features an active-high open-drain RESET output. It asserts HIGH during power-up, brownout (VCC < 4.63V), or watchdog timeout, and remains asserted until VCC exceeds the trip point for 200ms. An external pull-up resistor is required for proper logic-level translation to the host microcontroller. This differs from the X5043 variant, which uses active-low RESET.

Can the voltage reset threshold of the X5045S8I-4.5A be changed after soldering?

Yes, the X5045S8I-4.5A supports field reprogramming of its VTRIP threshold using a 15–18V pulse on the WP pin and specific SPI command sequences (WREN + write to address 01h). This allows adjustment to higher values (e.g., 4.63V → 4.70V) without replacing the component - useful for fine-tuning in production or addressing board-level voltage droop.

How does the watchdog timer function on the X5045S8I-4.5A?

The X5045S8I-4.5A watchdog timer monitors the CS/WDI pin: a HIGH-to-LOW transition must occur within the selected timeout period (200ms, 600ms, or 1.4s) to prevent RESET assertion. Timeout value is stored in nonvolatile WD0/WD1 bits and persists across power cycles. Default setting is disabled (WD1=WD0=1), requiring explicit configuration via WRSR command.

What EEPROM protection mechanisms does the X5045S8I-4.5A provide?

The X5045S8I-4.5A offers three layered protections: (1) Write Enable Latch (WEL) requiring WREN command before writes, (2) hardware WP pin that disables all nonvolatile writes when LOW, and (3) block lock bits (BL0/BL1) enabling software-selectable protection of 0%, 25%, 50%, or 100% of the 512×8 EEPROM array - preventing accidental overwrites of critical data.

Is the X5045S8I-4.5A compatible with 3.3V microcontrollers?

The X5045S8I-4.5A operates from 4.5–5.5V only and is not 3.3V-tolerant on VCC. While its SPI I/O pins meet standard CMOS voltage thresholds (VIH ≥ 0.7×VCC), interfacing with 3.3V MCUs requires level-shifting on SI, SO, SCK, and CS lines - or use of a 5V-tolerant MCU GPIO bank. Its 4.63V reset threshold is optimized for 5V system supervision.