Renesas X5045S8IZ-4.5AT1

Overview

X5045S8IZ-4.5AT1 from Intersil (now Renesas) is a CPU supervisor IC integrating power-on reset, watchdog timer, supply voltage supervision, and 4Kbit SPI EEPROM in an 8-lead SOIC package. It features 4.63V ±2.5% reset threshold, 200ms reset timeout, 3.3MHz SPI interface, and block-lock EEPROM protection. It serves as a system-level reliability manager in industrial microcontroller applications requiring brownout detection and nonvolatile configuration storage.

For engineers reviewing the X5045S8IZ-4.5AT1 datasheet, X5045S8IZ-4.5AT1 pinout, X5045S8IZ-4.5AT1 application, or X5045S8IZ-4.5AT1 equivalent, key selection criteria include VTRIP reprogrammability, watchdog timeout configurability (200ms/600ms/1.4s), 16-byte page write mode, active-low RESET output with 1V valid operation, and -40°C to +85°C industrial temperature range.

Technical Context

The X5045S8IZ-4.5AT1 implements a dual-function CS/WDI pin for chip select and watchdog input, with falling-edge-triggered watchdog reset. Its internal voltage monitor asserts RESET when VCC drops below 4.63V ±2.5%, holding it active until VCC exceeds the trip point for 200ms and stabilizes above 1V.

EEPROM operations use standard SPI protocol with MSB-first 8-bit instructions (WREN, READ, WRITE, RDSR, WRSR), supporting 1–16 byte page writes and status register control of block lock (BL0/BL1) and watchdog timing (WD0/WD1). The Direct Write™ cell ensures 1M write cycles and 100-year data retention.

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 integrated EEPROM applications.

Compared with MAX6361KA29+T and STM802LSD-46F, the X5045S8IZ-4.5AT1 uniquely combines field-reprogrammable VTRIP, 1M-cycle EEPROM, and dual-function CS/WDI in a single 8-pin SOIC-reducing component count, enabling adaptive brownout response, and eliminating external memory layout complexity.

Availability

X5045S8IZ-4.5AT1 is available at Aetrix Electronics and suitable for industrial process control, network infrastructure, and battery-powered telemetry applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for X5045S8IZ-4.5AT1 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 mixed-signal ICs for industrial, communications, and computing markets.

The X5045 family was designed as an integrated CPU supervisor solution targeting microcontroller-based systems needing coordinated reset, watchdog, voltage monitoring, and nonvolatile storage-all in one compact, reliable package.

FAQ

What is the factory-set VTRIP voltage for X5045S8IZ-4.5AT1?

The X5045S8IZ-4.5AT1 ships with a factory-programmed VTRIP of 4.63V ±2.5%, indicated by the "-4.5A" suffix. This threshold is optimized for 5V systems and remains stable over temperature and time unless reprogrammed using the VP = 15–18V procedure defined in the datasheet. The reset signal remains valid down to VCC = 1V, ensuring robust operation during deep brownouts.

How does the watchdog timer function on X5045S8IZ-4.5AT1?

The X5045S8IZ-4.5AT1 watchdog uses the CS/WDI pin: a falling edge resets the timer, and failure to toggle within the selected timeout (200ms/600ms/1.4s) asserts RESET. Timeout is set via nonvolatile WD0/WD1 bits in the status register and persists across power cycles. Unlike simple timers, it requires active MCU intervention-no automatic periodic refresh-and remains enabled even after power cycling unless explicitly disabled.

Can X5045S8IZ-4.5AT1's EEPROM be partially protected against writes?

Yes, X5045S8IZ-4.5AT1 supports four levels of block lock protection via BL0/BL1 bits: none, lower quarter (0x180–0x1FF), lower half (0x100–0x1FF), or full array (0x000–0x1FF). Protection is nonvolatile and enforced in hardware-write attempts to locked regions are ignored regardless of WREN state or WP pin level. This enables safe storage of immutable calibration data alongside user-modifiable configuration bytes.

What is the maximum SPI clock frequency supported by X5045S8IZ-4.5AT1?

X5045S8IZ-4.5AT1 supports a maximum SPI clock frequency of 3.3MHz under recommended operating conditions (VCC = 4.5–5.5V). This allows efficient data transfer-e.g., reading 512 bytes in under 2.5ms-while maintaining timing margins for noise immunity. All SPI operations (READ, WRITE, RDSR, WRSR) follow MSB-first protocol with setup/hold times specified at 30ns minimum.

Does X5045S8IZ-4.5AT1 require external components for basic reset functionality?

No, X5045S8IZ-4.5AT1 operates autonomously with no external components required for power-on reset, brownout detection, or watchdog supervision. Its internal POR circuit, voltage reference, and oscillator-free watchdog timer eliminate the need for RC networks or external crystals. Only pull-up resistors on RESET (if open-drain termination is needed) and optional decoupling capacitors are recommended for noise immunity and power stability.