Renesas X5045S8I-2.7T1

Overview

X5045S8I-2.7T1 from Intersil (now Renesas) is a 4K-bit SPI CPU supervisor IC integrating power-on reset, watchdog timer, supply voltage supervision, and block-lock protected EEPROM in an 8-pin SOIC package. It operates from 2.7V to 5.5V, features a factory-default 2.63V reset threshold (±2.5%), 200ms reset timeout, and supports 3.3MHz SPI communication for embedded microcontroller systems requiring reliable boot integrity and nonvolatile configuration storage.

For engineers reviewing the X5045S8I-2.7T1 datasheet, X5045S8I-2.7T1 pinout, X5045S8I-2.7T1 application, or X5045S8I-2.7T1 equivalent, this page delivers verified technical context, exact pin functions, real-world use cases in industrial control and communications equipment, and two validated alternative parts with documented functional and parametric differences.

Technical Context

The X5045S8I-2.7T1 implements a dual-function supervisory architecture: its POR circuit asserts RESET/RESET for ≥200ms after VCC exceeds 2.63V, while its independent watchdog timer monitors CS/WDI transitions and triggers reset if no toggle occurs within 200ms, 600ms, or 1.4s (configurable via nonvolatile status register bits WD1/WD0). The device uses a dedicated low-voltage detection comparator with hysteresis to maintain reset assertion until VCC rises above 2.63V and stabilizes.

Its 4K-bit (512 × 8) SPI EEPROM employs Intersil's Direct Write™ cell technology, enabling 1M write cycles and 100-year data retention. Block lock protection (BL0/BL1 bits) allows selective write-protection of 0%, 25%, 50%, or 100% of the array, enforced by both software (WRSR command) and hardware (WP pin).

Key Specifications

Pinout & Package

Package: 8-pin SOIC (Small Outline Integrated Circuit), RoHS-compliant, Pb-free plus anneal finish, -40°C to +85°C operating temperature range.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6361KA29+T and MCP809T-270I/SN, the X5045S8I-2.7T1 uniquely integrates reset, watchdog, voltage monitoring, and 4K-bit EEPROM in one SOIC-8 package-reducing BOM count, PCB area, and qualification effort for systems requiring coordinated boot integrity and persistent parameter storage.

Availability

X5045S8I-2.7T1 is available at Aetrix Electronics and suitable for industrial process control, network infrastructure, smart metering, and battery-powered IoT applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for X5045S8I-2.7T1 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 Corporation (formerly Intersil) is a global semiconductor leader specializing in microcontrollers, analog, power management, and timing solutions for industrial, automotive, and communications markets.

The X5045 family was designed to consolidate critical system supervision functions-power-on reset, watchdog, voltage monitoring, and nonvolatile storage-into a single, space-efficient IC for resource-constrained embedded systems.

FAQ

What is the reset polarity and output type of the X5045S8I-2.7T1?

The X5045S8I-2.7T1 features an active-high RESET output with open-drain configuration. This matches the "X5045" designation in the part number (versus X5043's active-low RESET). External pull-up is required for proper logic level translation and noise immunity in the host system. The X5045S8I-2.7T1 asserts RESET during power-up, brownout below 2.63V, or watchdog timeout.

How is the watchdog timeout period configured on the X5045S8I-2.7T1?

The watchdog timeout on the X5045S8I-2.7T1 is set via two nonvolatile bits (WD1 and WD0) in the status register, programmed using the WRSR instruction. Factory default is WD1=1, WD0=1 (watchdog disabled), but users may select 200ms, 600ms, or 1.4s. The setting persists across power cycles and does not require reconfiguration at boot.

Can the reset threshold voltage of the X5045S8I-2.7T1 be changed after soldering?

Yes-the X5045S8I-2.7T1 supports in-system VTRIP reprogramming. Applying the target voltage (e.g., 2.85V) to VCC, pulling WP to 15–18V, issuing WREN, then writing 00h to address 01h reprograms the threshold. This is performed in-circuit without removing the device, enabling field calibration for precision brownout detection.

What EEPROM protection mechanisms does the X5045S8I-2.7T1 provide?

The X5045S8I-2.7T1 implements three-tiered EEPROM protection: (1) hardware WP pin disable, (2) volatile write-enable latch (set via WREN), and (3) nonvolatile block lock bits (BL0/BL1) that protect 0%, 25%, 50%, or 100% of the 512×8 array. All layers must be satisfied for a write to succeed-ensuring robust data integrity in mission-critical systems.

Is the X5045S8I-2.7T1 compatible with standard SPI interfaces?

Yes-the X5045S8I-2.7T1 uses a standard four-wire SPI interface (CS/WDI, SO, SI, SCK) with MSB-first transmission, 3.3MHz max clock rate, and full compatibility with common microcontroller SPI peripherals. It supports read, write, status register access, and page writes without proprietary protocol extensions-enabling drop-in integration into existing SPI-based firmware stacks.