Renesas X4043S8Z-4.5A

Overview

X4043S8Z-4.5A from Intersil is a CPU supervisor IC integrating power-on reset control, watchdog timer, supply voltage supervision, and 4kbit EEPROM in an 8-pin SOIC package. It features active-low RESET output, 4.5V–4.75V reset threshold, 400kHz I²C interface, <20µA standby current (watchdog on), and Block Lock™ EEPROM protection - used in microcontroller-based embedded systems requiring reliable brownout detection and nonvolatile configuration storage.

For engineers reviewing the X4043S8Z-4.5A datasheet, X4043S8Z-4.5A pinout, X4043S8Z-4.5A application, or X4043S8Z-4.5A equivalent, key selection criteria include reset threshold accuracy (4.5–4.75V), EEPROM endurance (1M cycles), watchdog timeout options (200ms/600ms/1.4s), VCC operating range (4.5–5.5V), and SOIC-8 RoHS-compliant packaging for industrial-grade board-level reliability.

Technical Context

The X4043S8Z-4.5A implements a dual-function reset architecture: power-on reset with 250ms delay and low-VCC detection asserting RESET below 4.5V (typical trip at 4.625V). Its watchdog timer monitors SDA/SCL activity using a state machine that triggers reset if no valid I²C transaction occurs within the selected timeout interval.

Internally, it integrates a 512 × 8-bit EEPROM array organized into 16-byte pages, accessed via standard I²C protocol (slave address 0xA0 for writes, 0xA1 for reads). The device uses Direct Write™ memory cells enabling 100-year data retention and supports programmable VTRIP adjustment using 15–18V on WP pin - a feature confirmed for this exact part number per FN8118 Rev 3.00 ordering table.

Key Specifications

Pinout & Package

Package: 8-pin SOIC (Pb-free, RoHS-compliant; JEDEC MS-012AC, 150 mil width).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6375US46+T and STM8T142M2U6, the X4043S8Z-4.5A uniquely combines field-programmable VTRIP, 4kbit I²C EEPROM, and three watchdog timeouts in a pin-compatible SOIC-8 footprint - offering superior flexibility for field-deployed systems requiring post-production calibration and brownout tuning.

Availability

X4043S8Z-4.5A is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic devices, smart energy meters, and automotive infotainment head units requiring stable component supply with long-term lifecycle assurance.

Supply support for X4043S8Z-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 (now part of Renesas Electronics) designs high-performance analog and mixed-signal ICs for power management, precision sensing, and system supervision applications.

The X4043/X4045 product line was engineered specifically for embedded systems needing integrated reset, watchdog, and nonvolatile memory - reducing BOM count while improving reliability in space-constrained, cost-sensitive designs.

FAQ

What is the factory-programmed reset threshold voltage for X4043S8Z-4.5A?

The X4043S8Z-4.5A is factory-programmed with a reset threshold range of 4.5V to 4.75V, centered at approximately 4.625V. This specification is explicitly defined in the Ordering Information table of FN8118 Rev 3.00 for this exact part number. The threshold remains stable over temperature and time unless reprogrammed using the documented VTRIP adjustment procedure involving a 15–18V pulse on the WP pin.

Does X4043S8Z-4.5A support I²C communication at standard mode (100kHz) and fast mode (400kHz)?

Yes, X4043S8Z-4.5A supports Fast-mode I²C operation up to 400kHz as stated in the FEATURES section of FN8118 Rev 3.00. It is fully compatible with standard-mode (100kHz) as well. The device uses standard I²C protocol with slave address 0xA0 (write) and 0xA1 (read), and includes built-in acknowledge polling to manage write cycle completion without fixed delays.

Can the watchdog timer timeout period be changed after soldering X4043S8Z-4.5A onto a PCB?

Yes, the watchdog timeout period of X4043S8Z-4.5A can be reconfigured in-system via its I²C interface by writing to the nonvolatile control register at address 0x1FF. The WD1/WD0 bits support four states: 200ms, 600ms, 1.4s, or disabled. This change persists across power cycles and requires no hardware modification - confirmed in the "Control Register" section (Page 9) of FN8118 Rev 3.00.

Is the EEPROM in X4043S8Z-4.5A truly write-protected during power-up and brownout conditions?

Yes, X4043S8Z-4.5A provides automatic EEPROM write protection during brownout: when VCC falls below VTRIP, all I²C communication halts and in-progress writes complete safely before RESET asserts. Additionally, the Block Lock™ feature allows permanent or dynamic locking of 16-byte to full-array segments. These protections are hardware-enforced and require no firmware intervention.

What package type and lead finish does X4043S8Z-4.5A use?

X4043S8Z-4.5A is supplied in an 8-lead SOIC package (JEDEC MS-012AC, 150 mil width) with Pb-free plus anneal termination - fully RoHS-compliant and compatible with both SnPb and lead-free reflow profiles. This is explicitly stated in the Ordering Information table (Page 2) and Notes section of FN8118 Rev 3.00 for this exact part number.