Renesas X5045S8Z

Overview

X5045S8Z from Intersil (now Renesas) is a 4K-bit CPU supervisor IC integrating power-on reset, watchdog timer, supply voltage supervision, and SPI EEPROM in an 8-lead SOIC package. It features a 4.63V ±2.5% reset threshold, 3.3MHz SPI interface, and 100,000 write-cycle EEPROM endurance. It is used in embedded systems requiring reliable power sequencing and nonvolatile configuration storage, such as network routers and industrial controllers.

For engineers reviewing the X5045S8Z datasheet, X5045S8Z pinout, X5045S8Z application, or X5045S8Z equivalent, key selection criteria include its active-low RESET output, factory-default 200ms power-up reset timeout, programmable VTRIP voltage, 4.5–5.5V operating range, and block-lock protected 512 × 8-bit EEPROM array accessible via standard SPI protocol.

Technical Context

The X5045S8Z implements a dual-function CS/WDI pin that serves both chip select and watchdog input, with falling-edge-triggered watchdog reset. Its internal voltage monitor asserts RESET when VCC drops below 4.63V and holds it active until VCC exceeds that threshold for 200ms.

The device uses a nonvolatile status register to configure watchdog timeout (1.4s, 600ms, 200ms, or disabled) and EEPROM block lock protection (none, 1/4, 1/2, or full array). All memory writes require explicit WREN instruction and are subject to WP pin control and write-enable latch state.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (Pb-free, RoHS compliant), 0°C to +70°C operating temperature range.

Key Features

Applications

Equivalent & Alternatives

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

Compared with X5045S8Z, MAX6361KA29+T offers higher EEPROM endurance but lacks VTRIP adjustability and watchdog configurability, while MCP9800-I/P provides no supervision functionality-making X5045S8Z uniquely suited for integrated reset + memory applications requiring field-programmable thresholds.

Availability

X5045S8Z is available at Aetrix Electronics and suitable for industrial process controllers, network infrastructure equipment, and battery-powered data loggers requiring stable component supply and long-term lifecycle support.

Supply support for X5045S8Z 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

Renesas Electronics (formerly Intersil) is a global semiconductor manufacturer specializing in microcontrollers, analog, and power management solutions for industrial, automotive, and communications markets.

The X5045S8Z belongs to the X5043/X5045 family of CPU supervisors, designed to consolidate reset generation, watchdog monitoring, voltage supervision, and nonvolatile storage into a single SPI-compatible device for space-constrained embedded systems.

FAQ

What is the reset threshold voltage for X5045S8Z?

The X5045S8Z has a factory-programmed reset threshold of 4.63V ±2.5%, corresponding to the "-4.5A" suffix in its ordering code. This value is guaranteed over temperature and can be reprogrammed in-system using a 15–18V programming voltage applied to the WP pin and a defined SPI command sequence per the FN8126 datasheet.

Does X5045S8Z support both active-high and active-low reset outputs?

No, the X5045S8Z provides only an active-low open-drain RESET output. The "X5045" designation indicates active-low reset; the "X5043" variant provides active-high reset. Both share identical supervision, watchdog, and EEPROM functionality, but reset polarity is fixed per part number and cannot be changed.

How is the watchdog timer configured on X5045S8Z?

The X5045S8Z watchdog timeout is configured via two nonvolatile bits (WD0, WD1) in the status register, set using the WRSR instruction. Factory default is disabled (WD1=WD0=1). Valid timeouts are 200ms, 600ms, or 1.4s. The watchdog is triggered by CS/WDI pin transitions and resets on each falling edge, independent of SPI bus activity.

Can X5045S8Z EEPROM be written without enabling the write latch?

No. Before any write operation-including memory array or status register writes-the X5045S8Z requires the Write Enable Latch (WEL) to be set via the WREN instruction. The WEL bit is volatile and automatically resets after power-up, write completion, or when the WP pin is pulled low, preventing accidental writes.

What package type and temperature grade does X5045S8Z use?

The X5045S8Z is supplied in an 8-lead SOIC package (Pb-free, RoHS compliant) rated for commercial temperature operation from 0°C to +70°C. This matches the "S8Z" prefix in the part number and is distinct from industrial-grade variants (e.g., X5045S8IZ-4.5A) which use "S8IZ" and operate from –40°C to +85°C.