Renesas X5043M8IZ

Overview

X5043M8IZ from Intersil (now Renesas) is a CPU supervisor IC integrating power-on reset, watchdog timer, supply voltage supervision, and 4K-bit SPI EEPROM in an 8-lead MSOP package. It features 4.63V ±2.5% reset threshold, 200ms reset timeout, and 3.3MHz SPI interface - used for reliable microcontroller boot sequencing and nonvolatile configuration storage in industrial controllers.

For engineers reviewing the X5043M8IZ datasheet, X5043M8IZ pinout, X5043M8IZ application, or X5043M8IZ equivalent, key selection criteria include VTRIP reprogrammability, block-lock EEPROM protection, watchdog timeout configurability, and -40°C to +85°C industrial temperature operation.

Technical Context

The X5043M8IZ implements a dual-function CS/WDI pin that serves as both chip select and watchdog input, with falling-edge-triggered watchdog reset. Its internal power-on reset circuit asserts RESET/RESET until VCC exceeds 4.63V and remains stable for 200ms.

Voltage supervision uses a precision comparator with factory-trimmed 4.63V trip point (±2.5%), extendable via high-voltage programming sequence to custom thresholds. The 4K-bit EEPROM array (512 × 8) supports 16-byte page writes with 5ms typical write cycle time and 1M endurance using Direct Write™ technology.

Key Specifications

Pinout & Package

8-lead MSOP (Mini Small Outline Package), 3.0mm × 3.0mm body, 0.65mm lead pitch, RoHS-compliant Pb-free plus anneal finish.

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 MCP9800T-E/MS, X5043M8IZ uniquely combines reprogrammable VTRIP, 1M-endurance EEPROM, and configurable watchdog in a single 8-pin MSOP - making it irreplaceable for industrial systems requiring field-adjustable reset thresholds and long-term configuration integrity.

Availability

X5043M8IZ is available at Aetrix Electronics and suitable for industrial process controllers, network infrastructure equipment, and battery-powered remote sensors requiring stable component supply across extended product lifecycles.

Supply support for X5043M8IZ 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 management, and timing solutions for industrial, automotive, and communications markets.

The X5043 family was designed to consolidate power monitoring, reset generation, watchdog supervision, and nonvolatile storage into one IC - targeting space- and reliability-constrained embedded systems where discrete solutions increase failure risk and board cost.

FAQ

What is the factory-default VTRIP voltage for X5043M8IZ?

The X5043M8IZ ships with a factory-trimmed VTRIP voltage of 4.63V ±2.5%, corresponding to the "-4.5A" suffix in its ordering code. This threshold is laser-trimmed during production and remains stable over temperature and time unless reprogrammed using the high-voltage VTRIP adjustment procedure defined in the FN8126 datasheet. The X5043M8IZ maintains this setting across power cycles and retains it after reprogramming.

Can X5043M8IZ operate with a 3.3V supply?

No, X5043M8IZ is specified for 4.5V to 5.5V operation only, as indicated by its "-4.5A" suffix and confirmed in the Recommended Operating Conditions table (Page 13). Attempting to power the X5043M8IZ from 3.3V will result in improper reset assertion, unreliable EEPROM writes, and undefined watchdog behavior. For 3.3V systems, consider the X5043S8IZ-2.7A variant, which supports 2.7V–5.5V operation and 2.93V VTRIP.

How does the CS/WDI pin function in X5043M8IZ?

The CS/WDI pin on X5043M8IZ serves dual roles: as chip select for SPI communication (active-low) and as watchdog input. A falling edge on CS/WDI resets the watchdog timer; if no edge occurs within the selected timeout period (200ms/600ms/1.4s), RESET/RESET is asserted. During SPI transactions, CS/WDI must remain low for the full duration - toggling mid-operation corrupts the command sequence. The X5043M8IZ requires this pin to be actively managed by the host MCU for both interface and supervision.

What EEPROM protection modes does X5043M8IZ support?

X5043M8IZ supports four block lock protection levels via nonvolatile BL0/BL1 bits: none (00), upper quarter ($180–$1FF), upper half ($100–$1FF), or full array ($000–$1FF) write-protection. Protection is enforced independently of the WP pin and WREN latch - even with WP HIGH and WREN set, block-locked regions remain unwritable. This enables hierarchical security: e.g., bootloader region locked permanently while application parameters remain modifiable. The X5043M8IZ retains these settings across power cycles.

Is X5043M8IZ pin-compatible with X5045M8IZ?

Yes, X5043M8IZ and X5045M8IZ share identical 8-lead MSOP packaging, pinout, and electrical interface. The sole functional difference is reset polarity: X5043M8IZ provides active-low RESET, while X5045M8IZ provides active-high RESET/RESET. All other specifications - VTRIP, watchdog, EEPROM, timing, and protection - are identical. System designers may substitute X5045M8IZ only if their MCU accepts active-high reset signaling and the schematic accommodates the inverted logic level.