Renesas X4045S8IZ

Overview

X4045S8IZ from Intersil is a CPU supervisor IC integrating power-on reset control, watchdog timer, supply voltage supervision, and 4kbit EEPROM in a single 8-pin SOIC package. It provides active-high RESET output, operates from 2.7V to 5.5V, features five selectable V_TRIP thresholds (including factory-set 4.5V), supports 400kHz I²C interface, and delivers <1µA standby current with watchdog disabled - used in industrial microcontroller systems requiring reliable brownout protection and nonvolatile configuration storage.

For engineers reviewing the X4045S8IZ datasheet, X4045S8IZ pinout, X4045S8IZ application, or X4045S8IZ equivalent, key selection considerations include its -40°C to +85°C industrial temperature range, programmable V_TRIP capability, Block Lock™ EEPROM protection, open-drain RESET output requiring external pull-up, and compatibility with standard I²C bus timing and addressing protocols.

Technical Context

The X4045S8IZ implements a dual-function reset architecture: power-on reset asserts RESET for ≥250ms after V_CC stabilization, while low-V_CC detection holds RESET active until V_CC exceeds V_TRIP for ≥200ms and remains valid down to 1V. Its watchdog timer monitors SDA/SCL activity using four-instruction minimum restart sequences (START–SCL LOW–SCL HIGH–STOP) and offers three timeout options (200ms/600ms/1.4s) via nonvolatile WD1/WD0 bits.

EEPROM operation uses Intersil's Direct Write™ cell technology (1M write cycles, 100-year data retention), organized as 512 × 8-bit array with 16-byte page write mode and self-timed 5ms typical write cycle. Block Lock™ protection is controlled by BP2/BP1/BP0 bits, enabling selective write lock of 16–128 bytes or full array, while WP pin enables hardware-level write disable.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (Pb-free, RoHS compliant), JEDEC MS-012AC, 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 EEPROM applications.

Compared with MAX6361KA29+T and STM809SWX6F, the X4045S8IZ uniquely combines field-programmable V_TRIP, 400kHz I²C, and 4kbit Block Lock™ EEPROM in one industrial-grade package - eliminating BOM count and interconnect risk while enabling adaptive brownout response.

Availability

X4045S8IZ is available at Aetrix Electronics and suitable for industrial automation, medical device, smart metering, and automotive body electronics requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for X4045S8IZ 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 analog, and interface applications.

The X4045S8IZ belongs to Intersil's CPU Supervisor family, engineered to consolidate reset, watchdog, voltage monitoring, and EEPROM functions into single-chip solutions for space-constrained, reliability-critical embedded systems.

FAQ

What is the factory-set V_TRIP voltage for the X4045S8IZ?

The X4045S8IZ ships with a factory-programmed V_TRIP of 4.5V to 4.75V, optimized for 5V industrial systems. This threshold is stored in nonvolatile memory and can be reprogrammed using a 15–18V pulse on the WP pin followed by specific I²C commands. The device guarantees V_TRIP accuracy across its -40°C to +85°C operating range, and the reset signal remains valid down to V_CC = 1V.

Does the X4045S8IZ support I²C Fast-mode operation?

Yes, the X4045S8IZ supports standard I²C Fast-mode operation at up to 400kHz. Its SDA and SCL pins comply with I²C bus electrical specifications, including open-drain outputs with internal current-limited drivers and noise-immune timing margins. The device acknowledges slave address bytes and data words within standard setup/hold time windows, enabling seamless integration with microcontrollers such as STM32, PIC, and NXP Kinetis families.

How does the watchdog timer on the X4045S8IZ get reset?

The X4045S8IZ watchdog timer resets upon detection of a valid I²C START–SCL LOW–SCL HIGH–STOP sequence on the SDA/SCL bus - requiring exactly four microcontroller instructions. This sequence must occur within the selected timeout interval (200ms/600ms/1.4s). If missed, the device asserts the active-high RESET output. The timeout value is stored in nonvolatile WD1/WD0 bits and persists across power cycles unless rewritten via the control register.

Can the EEPROM in the X4045S8IZ be partially protected against writes?

Yes, the X4045S8IZ implements Block Lock™ protection controlled by BP2/BP1/BP0 bits in the nonvolatile control register. These bits enable selective write protection of 16, 32, 64, or 128 bytes, or the entire 512-byte EEPROM array. Protection is enforced at the hardware level - writes to locked regions are ignored and generate no acknowledge. The WP pin provides additional hardware-level disable of all writes when held HIGH.

What is the maximum write endurance and data retention of the X4045S8IZ EEPROM?

The X4045S8IZ EEPROM uses Intersil's Direct Write™ cell technology, guaranteeing a minimum of 1,000,000 write cycles and 100 years of data retention at +25°C. Retention is specified over the full -40°C to +85°C operating range, with accelerated testing confirming robustness against data corruption from thermal cycling and voltage stress. Page write mode (16-byte bursts) reduces wear compared to byte-by-byte writes.