Renesas X5045M8

Overview

X5045M8 from Intersil is a CPU supervisor IC integrating power-on reset control, watchdog timer, supply voltage supervision, and 4K-bit SPI EEPROM in an 8-lead MSOP package. It provides active-low RESET output, 4.63V ±2.5% VTRIP threshold, 1.4s/600ms/200ms selectable watchdog timeout, and 3.3MHz SPI interface - used in industrial process controllers to ensure deterministic microcontroller startup and brownout recovery.

For engineers reviewing the X5045M8 datasheet, X5045M8 pinout, X5045M8 application, or X5045M8 equivalent, key selection criteria include confirmed VTRIP reprogrammability, block-lock EEPROM protection granularity (1/4–full array), standby current under watchdog-on condition (<50µA), and compatibility with 2.7–5.5V supply rails in space-constrained embedded systems.

Technical Context

The X5045M8 implements a dual-function CS/WDI pin for chip select and watchdog input, with internal reset timing controlled by a 200ms delay after VCC exceeds VTRIP. Its status register contains nonvolatile WD0/WD1 bits that persist across power cycles and determine watchdog timeout without external configuration.

EEPROM operation uses Intersil's Direct Write™ cell architecture, enabling 1M write endurance and 100-year data retention. Block lock protection is enforced via BL0/BL1 bits in the status register, allowing selective write-protection of memory regions independent of WP pin state.

Key Specifications

Pinout & Package

Package: 8-lead MSOP (3.0mm × 3.0mm × 1.0mm height), Pb-free plus anneal RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6361KA29+T and MCP9808-E/MS, X5045M8 uniquely delivers reprogrammable VTRIP, 1M-cycle EEPROM, and triple watchdog timeout options in a single 8-pin MSOP - eliminating board space and BOM count penalties of multi-chip solutions in industrial control designs.

Availability

X5045M8 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 obsolescence management.

Supply support for X5045M8 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-reliability analog and mixed-signal ICs for industrial, communications, and computing markets.

The X5045M8 belongs to Intersil's CPU Supervisor family, engineered to consolidate reset, watchdog, voltage monitoring, and nonvolatile storage into one die - targeting space-constrained embedded systems needing deterministic power sequencing and data integrity.

FAQ

What is the factory-default VTRIP voltage for X5045M8?

The X5045M8 ships with a factory-programmed VTRIP of 4.63V ±2.5%, corresponding to the "-4.5A" suffix in its ordering code. This threshold is nonvolatile and persists across power cycles unless reprogrammed using the VP=15–18V method described in the FN8126 datasheet. The X5045M8 maintains this setting even after complete power loss, ensuring consistent brownout response in deployed systems.

Does X5045M8 support both active-low and active-high reset outputs?

No, the X5045M8 provides only an active-low open-drain RESET output. The "X5045" designation indicates active-low reset; the "X5043" variant offers active-high. The X5045M8 does not include an active-high option - design must accommodate pull-up resistor and logic-level inversion if active-high signaling is required. This is fixed per device variant and cannot be configured in-circuit.

How is the watchdog timeout period selected on X5045M8?

The watchdog timeout on X5045M8 is set via two nonvolatile bits (WD0 and WD1) in the status register, programmed using the WRSR instruction. Valid combinations yield 200ms (WD1=0, WD0=0), 600ms (WD1=0, WD0=1), 1.4s (WD1=1, WD0=0), or disabled (WD1=WD0=1, factory default). These bits retain their state across power cycles, eliminating need for MCU reinitialization at boot.

Can X5045M8's EEPROM be written to while the watchdog is active?

Yes, X5045M8 allows EEPROM writes during watchdog operation. The watchdog timer monitors only the CS/WDI pin state - toggling CS low periodically resets the timer without interrupting ongoing EEPROM read/write sequences. However, WP pin must be high and WREN command issued before any write, and block lock bits must permit access to target memory addresses.

What is the maximum SPI clock frequency supported by X5045M8?

The X5045M8 supports a maximum SPI clock frequency of 3.3MHz under recommended operating conditions (VCC = 4.5–5.5V, TA = 0°C to +70°C). This limit is specified in the AC Electrical Specifications table of FN8126 Rev 3.00 and applies to all operations including READ, WRITE, and RDSR. Exceeding 3.3MHz may cause timing violations and data corruption.