Renesas X5043S8IT1

Overview

X5043S8IT1 from Intersil is a CPU supervisor IC integrating power-on reset control, watchdog timer, supply voltage supervision, and 4Kbit SPI EEPROM in an 8-lead SOIC package. It provides active-low RESET output, supports 2.7–5.5V VCC, features four factory-programmable VTRIP thresholds (e.g., 2.63V, 2.93V), and delivers 1M write-cycle EEPROM endurance with block lock protection - used in industrial process controllers for brownout recovery and firmware parameter storage.

For engineers reviewing the X5043S8IT1 datasheet, X5043S8IT1 pinout, X5043S8IT1 application, or X5043S8IT1 equivalent, key selection criteria include its dual-function CS/WDI pin, reprogrammable reset threshold, 3.3MHz SPI interface timing, and support for 16-byte page writes with 5ms typical write cycle time.

Technical Context

The X5043S8IT1 implements a dedicated low-voltage detection circuit with hysteresis that asserts RESET/RESET until VCC exceeds the selected VTRIP by ≥200ms. Its watchdog timer uses nonvolatile WD0/WD1 bits to select fixed timeout intervals (200ms, 600ms, or 1.4s) and resets on CS/WDI toggling.

EEPROM operation follows standard SPI protocol with MSB-first 8-bit instructions (READ, WRITE, WREN, RDSR), requiring WREN latch activation and WP pin control. Block lock protection is configured via status register BL0/BL1 bits to secure 0%, 25%, 50%, or 100% of the 512×8 array.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (Pb-free, RoHS compliant), body size 4.9mm × 3.9mm × 1.75mm, standard JEDEC MS-012AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6816EUK+T and MCP9808-E/SN, the X5043S8IT1 uniquely integrates four essential functions - power-on reset, voltage supervision, watchdog timer, and 4Kbit SPI EEPROM - in one SOIC-8 device, enabling single-chip system-level reliability without compromising on configurability or endurance.

Availability

X5043S8IT1 is available at Aetrix Electronics and suitable for industrial process controllers, network infrastructure equipment, and battery-powered data loggers requiring stable component supply and long-term lifecycle support.

Supply support for X5043S8IT1 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 power management ICs for industrial, communications, and computing markets.

The X5043 family was developed to consolidate power supervision, watchdog safety, and nonvolatile memory into a single SPI-compatible device for space-constrained embedded systems.

FAQ

What is the default VTRIP threshold voltage for X5043S8IT1?

The X5043S8IT1 ships with a factory-programmed VTRIP threshold of 2.63V (±2.5%). This value is stored in nonvolatile circuitry and remains unchanged over temperature and time unless explicitly reprogrammed using the 15–18V VP sequence on the WP pin. The X5043S8IT1 datasheet confirms this as the standard -2.7 suffix variant's default trip point.

Does X5043S8IT1 support both active-low and active-high reset outputs?

No, the X5043S8IT1 provides only an active-low RESET/RESET output (open-drain). The X5045 variant offers active-high reset; X5043S8IT1 is strictly active-low. The datasheet specifies "X5043, RESET/RESET is an active low… open drain output" and shows no internal inversion logic - external pull-up is required for proper logic-level translation.

How many bytes can be written in a single page write operation for X5043S8IT1?

The X5043S8IT1 supports up to 16 bytes per page write operation. Each page spans addresses ending in 0000–1111 (e.g., 0x00–0x0F), and the device enforces page boundary alignment - writing beyond the 16-byte limit rolls the address counter back to the start of the page, overwriting prior data. This is documented in the "Write Memory Array" section of the X5043S8IT1 datasheet.

What is the maximum SPI clock frequency supported by X5043S8IT1?

The X5043S8IT1 supports a maximum SPI clock frequency of 3.3MHz under recommended operating conditions (VCC = 2.7–5.5V). AC Electrical Specifications table on page 14 of the X5043S8IT1 datasheet lists fSCK(MIN/MAX) as 0 to 3.3MHz, with timing parameters (tCYC, tSU, tH) validated at this rate.

Is the watchdog timer in X5043S8IT1 enabled by default after power-up?

No, the watchdog timer in X5043S8IT1 is disabled by default after power-up. The status register's WD0 and WD1 bits ship with value 11b, which corresponds to "watchdog disabled" per Table 2 in the X5043S8IT1 datasheet. Enabling requires issuing a WRSR command to set WD0/WD1 to 00b, 01b, or 10b - no timeout occurs unless explicitly configured.