Renesas X5043S8-4.5A

Overview

X5043S8-4.5A 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-lead SOIC package. It features a 4.63V ±2.5% reset threshold, 1.4s/600ms/200ms selectable watchdog timeout, and 512 × 8-bit EEPROM with 1M write endurance. It serves as a system-level reliability enhancer in network routers and industrial controllers requiring deterministic reset behavior and nonvolatile configuration storage.

For engineers reviewing the X5043S8-4.5A datasheet, X5043S8-4.5A pinout, X5043S8-4.5A application, or X5043S8-4.5A equivalent, this page delivers verified functional identity, validated pin roles, confirmed VTRIP and watchdog timing, real-world application context, and two technically documented alternative parts - all extracted from FN8126 Rev 3.00 and manufacturer ordering data.

Technical Context

The X5043S8-4.5A implements a dual-function supervisory architecture: analog voltage monitoring with programmable 4.63V trip point and digital watchdog logic tied to CS/WDI pin toggling. Its reset assertion remains valid down to VCC = 1V and holds for 200ms after VCC recovery.

Internally, it combines a serial EEPROM array organized as 512 × 8 bits with SPI interface (3.3MHz max), Direct Write™ memory cells (1M endurance, 100-year retention), and status register-controlled block lock protection (1/4, 1/2, full, or none of EEPROM). The WREN/WRDI instruction set and WP pin provide layered write protection.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (Pb-free, RoHS compliant), 0°C to +70°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 MAX6816EPA+ and MCP9808-E/P, the X5043S8-4.5A uniquely integrates four functions in one die - eliminating interconnect delays, reducing layout complexity, and enabling atomic write-protect sequences that discrete solutions cannot replicate.

Availability

X5043S8-4.5A is available at Aetrix Electronics and suitable for network infrastructure, industrial control, and consumer electronics applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for X5043S8-4.5A 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 high-performance analog and mixed-signal ICs for power management, precision analog, and interface applications.

The X5043 family was designed as an integrated reliability solution for microcontroller-based systems needing coordinated reset, watchdog supervision, voltage monitoring, and nonvolatile storage - targeting cost-sensitive, space-constrained embedded designs.

FAQ

What is the exact reset threshold voltage for X5043S8-4.5A?

The X5043S8-4.5A has a factory-programmed VTRIP threshold of 4.63V ±2.5%, validated per FN8126 Rev 3.00 Table on Page 2. This value applies specifically to the -4.5A suffix variant and is guaranteed over 0°C to +70°C. The threshold can be reprogrammed using the VP=15–18V sequence described on Page 6, but default shipment is 4.63V.

Does X5043S8-4.5A support both active-low and active-high reset outputs?

No - the X5043S8-4.5A provides only an active-low open-drain RESET output, as confirmed by its part number suffix (-4.5A denotes active-low reset) and Pin Descriptions on Page 5. The X5045 variant offers active-high reset; X5043S8-4.5A does not include that option.

How many watchdog timeout options does X5043S8-4.5A offer, and how are they selected?

The X5043S8-4.5A offers three watchdog timeout periods: 1.4s (factory default), 600ms, and 200ms. Selection is performed by writing nonvolatile WD0/WD1 bits in the Status Register using the WRSR instruction, as defined in Table 2 on Page 9. These bits retain their state across power cycles.

What is the maximum SPI clock frequency supported by X5043S8-4.5A?

The X5043S8-4.5A supports a maximum SPI clock frequency of 3.3MHz, specified in the AC Electrical Specifications table on Page 14. This limit applies across the full 4.5–5.5V VCC range and 0°C to +70°C temperature range, with timing parameters including tCYC ≥300ns and tSU/tH ≥30ns.

Can the EEPROM in X5043S8-4.5A be fully protected against writes?

Yes - the X5043S8-4.5A supports full EEPROM block lock protection via BL0/BL1 bits in the Status Register. When BL1=BL0=1, the entire 512×8 array ($000–$1FF) is write-protected while remaining readable, as shown in Table 2 on Page 9. This setting persists through power cycles and requires explicit WRSR command to modify.