Renesas X5043M8I

Overview

X5043M8I from Intersil is a CPU supervisor IC integrating power-on reset control, watchdog timer, supply voltage supervision, and 4K-bit SPI EEPROM in an 8-lead MSOP package. It features 4.63V reset threshold (±2.5%), 200ms reset timeout, 1.4s/600ms/200ms selectable watchdog intervals, <50µA standby current with watchdog enabled, and 3.3MHz SPI interface - deployed in industrial process controllers requiring reliable brownout protection and nonvolatile configuration storage.

For engineers reviewing the X5043M8I datasheet, X5043M8I pinout, X5043M8I application, or X5043M8I equivalent, this page delivers verified functional identity, exact VTRIP mapping (-4.5A suffix), MSOP-8 package validation, confirmed 512×8 EEPROM organization, and two validated alternative parts with documented technical and application differences.

Technical Context

The X5043M8I implements a dual-function reset architecture: POR circuitry asserts RESET/RESET for ≥200ms after VCC exceeds 4.63V, while low-VCC detection holds RESET/RESET active until VCC rises above 4.63V and stabilizes for 200ms. Its watchdog timer monitors CS/WDI transitions and triggers reset if no high-to-low edge occurs within the selected timeout interval (200ms/600ms/1.4s).

EEPROM operation uses standard SPI protocol with WREN/WRDI latch control, RDSR/WRSR status register access, and 16-byte page writes completing in 5ms typical. Block lock protection (BL0/BL1 bits) enables selective write-protection of 0%, 25%, 50%, or 100% of the 512×8 array, enforced alongside hardware WP pin and volatile write-enable latch.

Key Specifications

Pinout & Package

Package: 8-lead MSOP (3.0mm × 3.0mm × 1.0mm height), RoHS-compliant Pb-free plus anneal finish, rated for -40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with X5043M8I, MAX6361KA29+T offers lower unit cost but sacrifices VTRIP programmability and EEPROM endurance, while MCP9701-E/P omits EEPROM and watchdog entirely - making X5043M8I the sole option supporting integrated, field-tunable reset, robust watchdog, and high-endurance configuration storage in one MSOP-8 device.

Availability

X5043M8I is available at Aetrix Electronics and suitable for industrial process control, network infrastructure equipment, and battery-powered data loggers requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for X5043M8I 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 (now part of Renesas Electronics) designs high-reliability analog and mixed-signal ICs for industrial, communications, and computing markets, emphasizing precision voltage monitoring and system-level reliability.

The X5043 family targets embedded systems needing consolidated power management, fault detection, and nonvolatile storage - specifically engineered to replace discrete reset ICs, watchdog timers, and serial EEPROMs with a single-pin-compatible solution.

FAQ

What is the factory-set VTRIP voltage for X5043M8I?

The X5043M8I ships with a factory-programmed VTRIP of 4.63V ±2.5%, indicated by the "-4.5A" suffix in its full ordering code X5043M8IZ-4.5A. This threshold is laser-trimmed during production and remains stable over temperature and time unless reprogrammed using the 15–18V VP sequence described in the FN8126 datasheet.

Does X5043M8I support both active-low and active-high reset outputs?

No - the X5043M8I provides only an active-low open-drain RESET/RESET output. The "X5045" variant in the same family offers active-high reset, but X5043M8I is strictly active-low. External pull-up is required, and the output remains asserted until VCC exceeds 4.63V and stabilizes for 200ms.

How is the watchdog timeout period selected on X5043M8I?

The watchdog timeout on X5043M8I is set via nonvolatile WD0/WD1 bits in the status register, programmed using the WRSR instruction. Factory default is WD1=1, WD0=1 (watchdog disabled). Valid combinations yield 200ms (WD1=1, WD0=0), 600ms (WD1=0, WD0=1), or 1.4s (WD1=0, WD0=0) - all persist across power cycles.

Can X5043M8I's EEPROM be written in byte mode or only page mode?

X5043M8I supports both byte and page writes. While page writes (up to 16 bytes within the same 16-byte boundary) improve efficiency, individual byte writes are fully supported. Each write operation - whether byte or page - requires prior WREN instruction, correct address, and CS going HIGH after final data bit to initiate the 5ms typical internal write cycle.

What is the maximum junction temperature rating for X5043M8I in MSOP-8 package?

The X5043M8I is rated for operation from -40°C to +85°C ambient temperature. Its absolute maximum junction temperature is +135°C, with thermal resistance θ_JA ≈ 180°C/W for the MSOP-8 package. At 5.5V VCC and 3.3MHz SCK, typical power dissipation remains below 15mW, ensuring safe operation within industrial temperature limits without heatsinking.