Renesas X40431V14I-A

Overview

X40431V14I-A from Xicor is a triple-voltage CPU supervisor IC with integrated 4Kbit EEPROM, active-HIGH reset output, and 2-wire I²C interface. It monitors V_CC (V1), V2MON, and V3MON at factory-programmed thresholds (4.55–4.65V, 2.95–3.05V, 1.65–1.75V), provides selectable power-on reset timeout (200ms default), and supports watchdog timer intervals of 25ms/200ms/1.4s or disabled. It is used in network servers to ensure reliable boot sequencing and voltage fault detection during power-up and brownout conditions.

For engineers reviewing the X40431V14I-A datasheet, X40431V14I-A pinout, X40431V14I-A application, or X40431V14I-A equivalent, key selection considerations include its active-HIGH RESET output (X40431 variant), triple independent voltage monitoring capability, Block Lock™ EEPROM protection, 400kHz I²C interface, and programmable V_TRIP thresholds via high-voltage sequence on WDO.

Technical Context

The X40431V14I-A implements three independent voltage comparators - one for V_CC (V1MON), one for V2MON (supplied by V2MON itself), and one for V3MON (supplied by V3MON) - enabling true independent monitoring of three system rails even when V_CC fails. Its reset generation logic asserts RESET (active-HIGH CMOS) upon V_CC drop below V_TRIP1, manual reset assertion, or watchdog timeout.

Watchdog functionality is triggered by SDA/SCL activity: a valid I²C START–SCL toggle–STOP sequence resets the timer; absence within the selected interval activates WDO (open-drain active-LOW). The Fault Detection Register (FDR) at address 0FFh provides volatile status bits (LV1F/LV2F/LV3F/WDF/MRF) to identify the exact cause of reset.

Key Specifications

Pinout & Package

Package: 14-lead SOIC (Small Outline Integrated Circuit) and TSSOP (Thin Shrink Small Outline Package), both RoHS-compliant and surface-mount compatible.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triple-voltage supervisor with EEPROM applications.

Compared with MAX6361KA29D3+ and TPS3808G33DBVR, the X40431V14I-A uniquely delivers three independent voltage monitors, field-programmable thresholds, and 4Kbit EEPROM in one 14-pin package - reducing component count by ≥3 and eliminating inter-rail dependency in multi-power-domain systems.

Availability

X40431V14I-A is available at Aetrix Electronics and suitable for network servers, disk arrays, industrial PLCs, and telecom routers requiring stable component supply across extended temperature and long product lifecycles.

Supply support for X40431V14I-A 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

Xicor Inc. was a fabless semiconductor company specializing in nonvolatile memory and power management ICs, acquired by Intersil in 2004 and later integrated into Renesas Electronics.

The X4043x family was designed specifically for embedded systems requiring consolidated voltage supervision, watchdog protection, and secure configuration storage - targeting communication infrastructure and industrial control where reliability and integration are critical.

FAQ

What is the reset output polarity of X40431V14I-A?

The X40431V14I-A features an active-HIGH CMOS RESET output, as confirmed by the datasheet's PIN DESCRIPTION section for X40431/35 variants. This means the RESET pin drives HIGH during reset assertion and returns LOW when all monitored voltages stabilize above their V_TRIP thresholds for the programmed t_PURST period. This differs from the X40430/34 variants which provide active-LOW reset.

Can X40431V14I-A monitor three voltages simultaneously while V_CC is absent?

Yes - the X40431V14I-A's V2MON and V3MON comparators are powered directly from their respective input pins, not from V_CC. As stated in the PIN DESCRIPTION and PRINCIPLES OF OPERATION sections, V2FAIL and V3FAIL remain functional even when V_CC = 0, enabling true independent monitoring of secondary and tertiary rails during main supply failure.

How is the watchdog timer reset on X40431V14I-A?

The watchdog timer on X40431V14I-A is reset by issuing a specific I²C sequence: START condition, SCL toggle from HIGH to LOW, then STOP condition - all while SDA is held HIGH. This four-instruction pattern (Start, Clock Low, Clock High, Stop) must occur within the selected timeout interval (25ms/200ms/1.4s) to prevent WDO activation. No register write is required.

What EEPROM protection mechanisms does X40431V14I-A provide?

X40431V14I-A implements three-tier EEPROM protection: (1) hardware WP pin (HIGH disables all writes), (2) power-up/power-down voltage detection that blocks writes during transients, and (3) Block Lock™ - a nonvolatile BP bit that permanently protects the upper 256 bytes (addresses 100h–1FFh) from overwrite, safeguarding critical configuration data.

Is the V_TRIP threshold of X40431V14I-A field-programmable?

Yes - the V_TRIP1, V_TRIP2, and V_TRIP3 thresholds of X40431V14I-A can be reprogrammed in-system using a high-voltage sequence applied to the WDO pin. The procedure requires applying the target voltage to the corresponding monitor pin (V_CC, V2MON, or V3MON), then pulsing WDO to V_P > 10V before issuing a specific I²C write command - enabling precision calibration without replacing the component.