Renesas X5043S8IZ-2.7

Overview

X5043S8IZ-2.7 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 a 2.85V–3.0V reset threshold, -40°C to +85°C industrial temperature range, and supports 3.3MHz SPI communication. It is used in embedded systems requiring reliable power sequencing and nonvolatile configuration storage.

For engineers reviewing the X5043S8IZ-2.7 datasheet, X5043S8IZ-2.7 pinout, X5043S8IZ-2.7 application, or X5043S8IZ-2.7 equivalent, this page delivers verified technical context, exact pin functions, real-world use cases, and validated alternative parts for industrial microcontroller supervision and EEPROM-backed system state retention.

Technical Context

The X5043S8IZ-2.7 implements a dual-function supervisory architecture: its analog voltage monitor asserts RESET/RESET when VCC drops below 2.85V (±2.5%), with reset hold time of 200ms after VCC recovery; simultaneously, its programmable watchdog timer monitors CS/WDI transitions and triggers reset if no high-to-low edge occurs within 200ms, 600ms, or 1.4s-configurable via nonvolatile status register bits WD0/WD1.

Its SPI EEPROM block is organized as 512 × 8 bits with Block Lock™ protection (BL0/BL1 bits), supporting 16-byte page writes and 1M write-cycle endurance. The device uses Direct Write™ memory cells, enabling 100-year data retention and operation down to VCC = 1V while maintaining valid reset signaling.

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 MCP809T-290I/SN, the X5043S8IZ-2.7 uniquely combines field-reprogrammable VTRIP, 4Kbit EEPROM with Block Lock™, and 3.3MHz SPI - delivering higher integration, tighter voltage tolerance, and longer data retention for industrial and medical edge devices.

Availability

X5043S8IZ-2.7 is available at Aetrix Electronics and suitable for industrial process controllers, network infrastructure equipment, medical diagnostic devices, and battery-powered IoT sensors requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for X5043S8IZ-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

Renesas Electronics (formerly Intersil) is a global semiconductor leader specializing in microcontrollers, analog, power, and trusted secure solutions for industrial, automotive, and infrastructure markets.

The X5043 family was designed to consolidate power supervision, watchdog, and nonvolatile memory into a single chip - reducing system cost and PCB area while improving reliability in mission-critical embedded applications.

FAQ

What is the exact reset voltage threshold for X5043S8IZ-2.7?

The X5043S8IZ-2.7 has a factory-set VTRIP of 2.85V ±2.5%, corresponding to the "-2.7A" suffix per the ordering table. This threshold is reprogrammable in-system using a 15–18V programming voltage applied to the WP pin and a specific SPI command sequence. The device retains the new threshold value across power cycles due to nonvolatile configuration storage.

Does X5043S8IZ-2.7 support both active-low and active-high reset outputs?

No - the X5043S8IZ-2.7 provides only an active-low open-drain RESET output (pin 8). The datasheet confirms RESET/RESET is active-low; there is no active-high variant in the X5043 series. For active-high reset functionality, designers must use an external inverter or select the pin-compatible X5045S8IZ-2.7, which offers active-high RESET.

How does the watchdog timer in X5043S8IZ-2.7 get reset during normal operation?

The watchdog timer in X5043S8IZ-2.7 is reset by a high-to-low transition on the CS/WDI pin (pin 1). This dual-function pin serves as chip select during SPI communication and as the watchdog input. The timer period - 200ms, 600ms, or 1.4s - is set nonvolatily via WD0/WD1 bits in the status register and persists through power cycles.

Can X5043S8IZ-2.7's EEPROM be written to while the watchdog is enabled?

Yes - the EEPROM and watchdog functions operate independently. Writing to EEPROM (via WRITE instruction) does not interfere with watchdog timing, and enabling the watchdog does not restrict EEPROM access. However, both require the Write Enable Latch (WEL) to be set first, and the WP pin must be HIGH to allow writes. Block Lock™ protection settings also apply regardless of watchdog state.

What is the minimum VCC required for X5043S8IZ-2.7 to assert a valid RESET signal?

The X5043S8IZ-2.7 guarantees valid RESET assertion down to VCC = 1V, as specified in the "Reset signal valid to VCC = 1V" feature list. Below 1V, the internal circuitry cannot maintain proper biasing, and RESET behavior is undefined. This ultra-low-voltage operation ensures fail-safe shutdown even during severe brownout conditions before complete power collapse.