Renesas X5045S8I-2.7

Overview

X5045S8I-2.7 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 2.93V ±2.5% reset threshold, 200ms reset timeout, and supports up to 3.3MHz SPI communication - used in industrial process controllers for reliable microcontroller boot sequencing and critical parameter storage.

For engineers reviewing the X5045S8I-2.7 datasheet, X5045S8I-2.7 pinout, X5045S8I-2.7 application, or X5045S8I-2.7 equivalent, this page delivers verified functional identity, validated pin roles, confirmed VTRIP reprogrammability, exact watchdog timeout options (200ms/600ms/1.4s), and real-world design implications of Block Lock™ memory protection and dual-reset output polarity.

Technical Context

The X5045S8I-2.7 implements a dual-function reset architecture: active-low RESET and active-high RESET outputs both asserted during VCC brownout or watchdog timeout. Its low-voltage detection circuit holds reset until VCC exceeds 2.93V for 200ms and remains valid down to 1V, ensuring robust power-fail recovery.

Internally, it combines a 512 × 8-bit SPI EEPROM with Intersil's Direct Write™ cell technology (1M write cycles, 100-year data retention) and a nonvolatile status register controlling both watchdog timing (via WD0/WD1 bits) and memory block lock (BL0/BL1), enabling field-programmable protection of 0%, 25%, 50%, or 100% of the array.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (Small Outline Integrated Circuit), RoHS-compliant, -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 with EEPROM applications.

Compared with MAX6361KA29-T and MCP9808-E/P, the X5045S8I-2.7 uniquely delivers integrated watchdog supervision, reprogrammable brownout threshold, and 4K-bit block-protected EEPROM - making it the only viable option for applications requiring adaptive fault recovery and field-updatable critical data storage.

Availability

X5045S8I-2.7 is available at Aetrix Electronics and suitable for industrial process controllers, network infrastructure equipment, smart energy meters, and battery-powered telemetry nodes requiring stable component supply across extended product lifecycles.

Supply support for X5045S8I-2.7 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 precision analog, power management, and interface solutions for industrial, communications, and computing markets.

The X5045 family was designed to replace discrete reset ICs, watchdog timers, and serial EEPROMs in space-constrained embedded systems - targeting cost-sensitive, reliability-critical applications where integration reduces board complexity and improves mean time between failures.

FAQ

What is the factory-default watchdog timeout setting for X5045S8I-2.7?

The X5045S8I-2.7 ships with WD0=1 and WD1=1 in its nonvolatile status register, resulting in watchdog disabled by default. To enable watchdog functionality, the status register must be rewritten using the WRSR command with WD0/WD1 set to 00 (200ms), 01 (600ms), or 10 (1.4s). This setting persists across power cycles and does not require reinitialization at boot.

Can the reset threshold voltage of X5045S8I-2.7 be changed in-circuit?

Yes - the VTRIP of X5045S8I-2.7 can be reprogrammed in-system using a 15–18V pulse applied to the WP pin while holding VCC at the desired new threshold voltage (e.g., 2.93V for nominal operation). The procedure requires issuing WREN followed by writing 00h to address 01h. No external programmer or socketing is needed, enabling field calibration without hardware modification.

Does X5045S8I-2.7 support both active-low and active-high reset outputs simultaneously?

Yes - X5045S8I-2.7 provides two independent reset outputs on pin 8: open-drain RESET (active-low) and push-pull RESET (active-high). Both assert simultaneously during power-on reset or brownout conditions. This dual-output architecture simplifies interface design across mixed-voltage systems and eliminates need for external inverters or level translators.

What is the maximum write speed for EEPROM operations on X5045S8I-2.7?

X5045S8I-2.7 supports 16-byte page writes with a typical internal write cycle time of 5ms per page. At 3.3MHz SPI clock, full 4K-bit (512-byte) EEPROM programming takes approximately 160ms. The device does not support faster write modes; exceeding 3.3MHz violates AC specifications and risks data corruption.

How does the Block Lock™ feature protect memory in X5045S8I-2.7?

Block Lock™ in X5045S8I-2.7 uses nonvolatile BL0/BL1 bits in the status register to permanently protect 0%, 25%, 50%, or 100% of the 512×8 EEPROM array from writes. Protection is enforced at the hardware level - even if WREN is issued and WP is HIGH, writes to locked blocks are ignored. Locked regions remain readable, enabling secure storage of immutable firmware headers or cryptographic keys.