Renesas X5045S8-2.7T1

Overview

X5045S8-2.7T1 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 features 2.93V reset threshold, 200ms reset timeout, 3.3MHz SPI interface, and operates across 2.7–5.5V supply. It is used in industrial process controllers to ensure reliable microcontroller startup and brownout recovery.

For engineers reviewing the X5045S8-2.7T1 datasheet, X5045S8-2.7T1 pinout, X5045S8-2.7T1 application, or X5045S8-2.7T1 equivalent, key selection criteria include VTRIP reprogrammability, 1M write-cycle EEPROM endurance, active-low RESET output timing, and watchdog timeout configurability via status register bits WD0/WD1.

Technical Context

The X5045S8-2.7T1 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 2.93V ±2.5%, holding it active until VCC exceeds the trip point for 200ms and stabilizes.

EEPROM operation uses SPI protocol with MSB-first 8-bit instructions (e.g., READ=0000 A8011, WREN=0000 0110), 16-byte page writes, and nonvolatile status register control of both block lock (BL0/BL1) and watchdog timeout (WD0/WD1). The Direct Write™ cell enables 1M write cycles and 100-year data retention.

Key Specifications

Pinout & Package

Package: 8-pin SOIC (Small Outline Integrated Circuit), RoHS-compliant Pb-free plus anneal finish, 150°C MSL rating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6361KA29+T and MCP809T-290I/SN, the X5045S8-2.7T1 uniquely integrates supervisory logic, reprogrammable reset threshold, and 4K-bit EEPROM in one SOIC-8 package-eliminating three discrete components while enabling field-updatable configuration and fault history storage.

Availability

X5045S8-2.7T1 is available at Aetrix Electronics and suitable for industrial process control, network infrastructure, consumer set-top boxes, and battery-powered data loggers requiring stable component supply across extended product lifecycles.

Supply support for X5045S8-2.7T1 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

Intersil Corporation (acquired by Renesas Electronics in 2017) is a semiconductor design house specializing in precision analog, power management, and interface ICs for industrial and communications markets.

The X5045 family was designed to consolidate reset, watchdog, voltage monitoring, and nonvolatile storage into a single SPI-accessible device-targeting space-constrained, reliability-critical embedded systems where firmware robustness and field serviceability matter.

FAQ

What is the exact VTRIP voltage for X5045S8-2.7T1, and can it be changed?

The X5045S8-2.7T1 ships with a factory-programmed VTRIP of 2.93V ±2.5%. Yes, it can be reprogrammed to a higher value using a 15–18V pulse on the WP pin while applying the desired VTRIP voltage to VCC and issuing a specific WREN + write-to-address-01h sequence. This allows field calibration for tighter system tolerances.

Does X5045S8-2.7T1 support both active-high and active-low reset outputs?

No. The X5045S8-2.7T1 provides only an active-low RESET output (open-drain). The "X5045" designation indicates active-low reset; the "X5043" variant offers active-high. Pin 8 is labeled RESET and asserts LOW during power-up, brownout, or watchdog timeout-requiring an external pull-up resistor.

How many write cycles does the EEPROM in X5045S8-2.7T1 support, and what is its data retention?

The EEPROM in X5045S8-2.7T1 supports a minimum of 1,000,000 write cycles and guarantees data retention for at least 100 years at +25°C. This is enabled by Intersil's proprietary Direct Write™ cell technology, making it suitable for applications requiring frequent parameter updates or long-term archival storage.

What watchdog timeout options are available on X5045S8-2.7T1, and how are they configured?

The X5045S8-2.7T1 offers four watchdog timeout options: disabled (factory default), 200ms, 600ms, or 1.4 seconds. These are selected by writing to the nonvolatile WD0 and WD1 bits in the status register using the WRSR instruction. Once set, the timeout persists across power cycles and does not require reconfiguration.

Is X5045S8-2.7T1 compatible with standard SPI interfaces, and what is its maximum clock rate?

Yes, the X5045S8-2.7T1 is fully compatible with standard SPI master interfaces. It supports a maximum SCK frequency of 3.3MHz, uses MSB-first transmission, and follows standard SPI timing with data latched on SCK rising edge (SI) and output on falling edge (SO). No special protocol extensions are required beyond the documented instruction set.