Renesas X5043P

Overview

X5043P from Intersil (now Renesas) is a CPU supervisor IC integrating power-on reset control, watchdog timer, supply voltage supervision, and 4K-bit SPI EEPROM in a single 8-lead PDIP package. It features a 4.63V ±2.5% reset threshold, selectable 200ms/600ms/1.4s watchdog timeout, and 512 × 8-bit EEPROM with block lock protection - deployed in industrial process controllers to ensure deterministic microcontroller startup and brownout recovery.

For engineers reviewing the X5043P datasheet, X5043P pinout, X5043P application, or X5043P equivalent, key selection considerations include its active-low RESET output timing (200ms release delay), VTRIP reprogrammability via VP=15–18V sequence, SPI interface compliance at 3.3MHz, and dual write-protection layers (WP pin + status-register-controlled block lock).

Technical Context

The X5043P implements a dedicated low-voltage detection comparator with hysteresis, driving an open-drain RESET output that remains asserted until VCC exceeds 4.63V for 200ms. Its watchdog circuit monitors CS/WDI transitions and triggers reset if no high-to-low edge occurs within the selected timeout interval - independent of SPI bus activity.

EEPROM operation uses standard SPI protocol with MSB-first 8-bit instructions (WREN, READ, WRITE, WRSR), 16-byte page writes, and internal Direct Write™ cells enabling 1M write cycles and 100-year data retention. Block lock protection is controlled by nonvolatile BL0/BL1 bits in the status register, allowing selective write-disable of 0%, 25%, 50%, or 100% of the 512-byte array.

Key Specifications

Pinout & Package

Package: 8-lead PDIP (Plastic Dual In-line Package), Pb-free, RoHS compliant, 0°C to +70°C operating temperature.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6361LKA29+T and MCP809T-460I/P, the X5043P delivers integrated functionality (supervision + EEPROM + watchdog), field-adjustable reset voltage, and superior EEPROM endurance - making it optimal for space-constrained, long-life embedded systems requiring guaranteed data integrity.

Availability

X5043P is available at Aetrix Electronics and suitable for industrial process controllers, rack-mount network servers, and battery-powered data loggers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for X5043P 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 power management, precision analog, and mixed-signal ICs for industrial, communications, and computing markets.

The X5043P belongs to Intersil's CPU Supervisor family, designed to consolidate reset, watchdog, voltage monitoring, and nonvolatile storage into one device - targeting embedded systems where reliability, board space, and BOM simplification are critical.

FAQ

What is the factory-programmed reset threshold voltage for X5043P?

The X5043P is shipped with a factory-programmed VTRIP of 4.63V ±2.5%, corresponding to the "-4.5A" suffix in its full ordering part number X5043PZ-4.5A. This threshold is guaranteed over temperature and remains stable across normal operating conditions unless reprogrammed using the VP=15–18V sequence described in the datasheet.

Does X5043P support both active-low and active-high reset outputs?

No - the X5043P provides only an active-low open-drain RESET output. The datasheet distinguishes X5043 (active-low) from X5045 (active-high), and the part number X5043P explicitly identifies the active-low variant. An external pull-up resistor is required to generate a logic-high signal when RESET is inactive.

How does the watchdog timer in X5043P get reset during normal operation?

The X5043P watchdog timer is reset by a falling edge on the CS/WDI pin. The microcontroller must toggle CS from HIGH to LOW at least once per selected timeout interval (200ms/600ms/1.4s). This action clears the internal watchdog counter; failure to do so causes RESET assertion. The timeout setting is stored in nonvolatile status register bits WD0/WD1.

Can the EEPROM in X5043P be written to while the watchdog is enabled?

Yes - the EEPROM and watchdog functions operate independently. Enabling the watchdog timer has no effect on SPI EEPROM read/write operations. However, both require the Write Enable Latch (WEL) to be set via WREN instruction, and both remain blocked if the WP pin is held LOW.

What is the maximum clock frequency supported by the SPI interface of X5043P?

The X5043P supports a maximum SPI clock frequency of 3.3MHz under recommended operating conditions (VCC = 4.5V–5.5V). This allows high-speed configuration reads and firmware parameter updates while maintaining timing margins for robust communication with common microcontrollers.