Renesas X40415V8I-C

Overview

X40415V8I-C from Intersil is a dual-voltage supervisor IC with integrated 4kbit EEPROM, watchdog timer, and power-on reset circuitry - featuring programmable VTRIP1/VTRIP2 thresholds (2.55–2.65V / 1.25–1.35V), 0.4s power-on reset timeout, and 200ms watchdog interval. It serves as a system-level CPU supervisor in embedded controllers monitoring 3.3V/1.2V rails.

For engineers reviewing the X40415V8I-C datasheet, X40415V8I-C pinout, X40415V8I-C application, or X40415V8I-C equivalent, key selection criteria include dual-supply fault detection with independent V2MON sensing, I²C-compatible 400kHz serial interface, EEPROM block-lock security, and operation down to 1V VCC for brownout resilience.

Technical Context

The X40415V8I-C implements two independent voltage comparators: V1MON (VCC) with factory-set 2.55–2.65V trip point and V2MON with 1.25–1.35V threshold, both supporting user reprogramming via high-voltage sequence on WDO. Its watchdog timer monitors SDA/SCL activity and asserts open-drain WDO on timeout.

Reset logic delivers active-HIGH RESET output synchronized to VCC recovery and tPURST delay; V2FAIL provides open-drain power-fail warning. The device integrates a 512×8 EEPROM array with 16-byte page write, 5ms typical write cycle, and nonvolatile control register managing BP, WD1/WD0, and PUP1/PUP0 bits.

Key Specifications

Pinout & Package

Package: 8-pin SOIC (Small Outline Integrated Circuit), surface-mount, 150 mil width.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6361KA29D3+T and TPS3808G18DBVR, the X40415V8I-C uniquely integrates dual-voltage supervision, EEPROM, and watchdog in one SOIC-8 package - delivering system-level reliability where component count, diagnostic capability, and rail coordination matter.

Availability

X40415V8I-C is available at Aetrix Electronics and suitable for communication equipment, industrial process control, and embedded computer systems requiring stable component supply and long-term lifecycle support.

Supply support for X40415V8I-C 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 Corporation was a U.S.-based semiconductor company specializing in precision analog and power management ICs, acquired by Renesas Electronics in 2017.

The X404xx family was designed as integrated CPU supervisors targeting space-constrained embedded systems needing coordinated power monitoring, reset control, and secure nonvolatile storage - particularly in networking and industrial automation.

FAQ

What is the factory-default watchdog timeout setting for X40415V8I-C?

The X40415V8I-C ships with WD1/WD0 bits set to "11", disabling the watchdog timer by default. To enable 200ms timeout, the host must write "01" to WD1/WD0 in the nonvolatile control register using the three-step WEL/RWEL sequence. This setting persists across power cycles and requires no external components to activate.

Can X40415V8I-C monitor a 1.2V rail without external resistors?

Yes - X40415V8I-C directly monitors 1.2V on the V2MON pin with a factory-trimmed 1.25–1.35V threshold. Unlike many supervisors requiring resistor dividers for sub-3V rails, this device's V2MON input is designed for direct connection to low-voltage cores, eliminating component count and tolerance errors in precision applications.

How does the RESET output behave during VCC brownout on X40415V8I-C?

The X40415V8I-C asserts active-HIGH RESET whenever VCC falls below its VTRIP1 threshold (2.55–2.65V) and holds it active until VCC rises above that threshold plus tPURST (0.4s). Crucially, RESET remains valid down to VCC = 1V, ensuring deterministic microcontroller halt even during deep undervoltage conditions where most supervisors lose functionality.

Is the EEPROM in X40415V8I-C compatible with standard I²C protocols?

Yes - the X40415V8I-C EEPROM responds to standard I²C start/stop conditions and slave address 0xA0h (write) / 0xA1h (read). It supports byte and 16-byte page writes, random reads, and acknowledge polling. Its 400kHz maximum clock rate and open-drain SDA/SCL interfaces ensure interoperability with common microcontroller I²C peripherals without protocol translation.

What happens to the Fault Detection Register after a system reset on X40415V8I-C?

At power-up, the Fault Detection Register (FDR) initializes to all zeros. Before monitoring begins, the host must write 0xFF to address 0xFF to arm the register. When a fault occurs (e.g., LV1F due to VCC drop), the corresponding bit clears to "0". After reading the FDR, the host must rewrite 0xFF to re-arm it - making the X40415V8I-C's FDR a volatile, software-managed diagnostic latch rather than an auto-clearing status register.