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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Supervisors

Renesas X40431S14-B

Name: X40431S14-B
Brand: Renesas
SKU: X40431S14-B
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: X40431S14-B

Manufacturer:: Renesas

Category:: Supervisors

Package:: 14-SOIC (0.154", 3.90mm Width)

Datasheet:: X40431S14-B.pdf

Description:: IC SUPERVISOR 3 CHANNEL 14SOIC

Quantity:: RFQ Add To RFQ list

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Product details

Overview

X40431S14-B from Xicor (now part of Renesas) is a triple-voltage CPU supervisor IC with integrated 4Kbit EEPROM, watchdog timer, and manual reset input. It monitors V_CC (V1), V2MON, and V3MON at factory-programmed thresholds (4.55–4.65 V, 2.85–2.95 V, 1.65–1.75 V), asserts active-low RESET and open-drain WDO/V2FAIL/V3FAIL outputs, and operates from 2.7 V to 5.5 V with 25 µA standby current (watchdog on). It is used in network storage controllers requiring coordinated power-fail warning and nonvolatile configuration retention.

For engineers reviewing the X40431S14-B datasheet, X40431S14-B pinout, X40431S14-B application, or X40431S14-B equivalent, key selection criteria include triple independent voltage monitoring capability, programmable reset timeout (50/200/400/800 ms), selectable watchdog intervals (25 ms/200 ms/1.4 s/off), 400 kHz I²C interface, and Block Lock™ EEPROM protection - all in a 14-pin SOIC/TSSOP package.

Technical Context

The X40431S14-B implements three independent comparator-based voltage monitors with dedicated fail outputs (LOWLINE, V2FAIL, V3FAIL), each capable of detecting undervoltage conditions without dependency on V_CC (V2MON/V3MON comparators are self-powered). Its reset generation logic combines power-on reset, brownout detection, and debounced manual reset into a single active-low RESET output with configurable t_PURST.

Watchdog functionality is triggered by SDA/SCL activity; a valid I²C start-stop sequence resets the timer, while absence within the selected interval activates WDO. The 4Kbit EEPROM uses Xicor's Direct Write™ cell architecture (100,000 write cycles, 100-year data retention) and supports 16-byte page writes with 5 ms typical cycle time.

Key Specifications

Parameter	Value and Actual Design Meaning
V_TRIP1	4.55–4.65 V: Factory-set primary supply monitor threshold for 5 V systems; ensures reliable reset assertion before microcontroller instability.
V_TRIP2	2.85–2.95 V: Factory-set secondary monitor threshold for 3 V rails; enables early power-fail warning on unregulated supplies.
V_TRIP3	1.65–1.75 V: Factory-set tertiary monitor threshold for 1.8 V cores; supports independent low-voltage domain supervision.
t_PURST	200 ms (factory default): Configurable power-on reset timeout; prevents premature processor execution during supply ramp-up.
Watchdog Interval	25 ms / 200 ms / 1.4 s / off: Selectable via nonvolatile control bits; provides flexible firmware liveliness checking without external components.
I²C Speed	400 kHz: Full-speed I²C compatibility; enables fast EEPROM read/write and real-time status register access.
Standby Current	25 µA (watchdog on): Ultra-low quiescent current during system idle; minimizes impact on battery-backed or energy-constrained designs.

Pinout & Package

Package: 14-lead SOIC (width 3.9 mm) and TSSOP (width 4.4 mm), both RoHS-compliant and lead-free.

Pin/Terminal	Circuit Role	Design Meaning
1 V2FAIL	Open-drain voltage fail indicator	Asserts LOW when V2MON < V_TRIP2; requires external pull-up; usable as interrupt or OR'd reset source.
2 V2MON	Secondary voltage monitor input	Self-powered analog input; monitors 3 V rail directly or via resistor divider; functional even if V_CC = 0.
3 LOWLINE	Early V_CC undervoltage flag	CMOS output asserting LOW at V_TRIP1 with no t_PURST delay; enables preemptive system shutdown.
4 NC	No connect	Not internally bonded; must remain unconnected per design.
5 MR	Debounced manual reset input	Active-low push-button interface; internal RC debounce eliminates external components.
6 RESET	Active-low reset output	Open-drain output asserted during V_CC brownout, manual reset, or power-on; holds for t_PURST.
7 V_SS	Ground reference	Primary return path for all analog and digital circuitry; must be low-impedance connection.
8 SDA	I²C bidirectional data line	Open-drain interface with always-active input buffer; supports standard and fast-mode I²C up to 400 kHz.
9 SCL	I²C clock input	Master-generated clock controlling EEPROM and register access timing; tolerant of slow edges.
10 WP	Hardware write protect	High-level lock disabling all EEPROM and register writes; internal 10 MΩ pull-down ensures safe default state.
11 V3MON	Tertiary voltage monitor input	Self-powered analog input for 1.8 V domain; monitors third rail independently of V_CC status.
12 V3FAIL	Open-drain tertiary fail indicator	Asserts LOW when V3MON < V_TRIP3; identical timing behavior to V2FAIL.
13 WDO	Watchdog timeout output	Active-low open-drain signal indicating firmware hang; may drive system reset or alert logic.
14 V_CC	Primary supply input	2.7–5.5 V operating range; powers internal logic, V_CC monitor, and I²C interface circuitry.

Key Features

Feature	Design Value
Triple independent voltage monitoring	Simultaneous supervision of V_CC, V2MON, and V3MON with separate fail outputs - eliminates need for three discrete supervisors.
Reprogrammable trip thresholds	V_TRIP1/V_TRIP2/V_TRIP3 adjustable via I²C high-voltage programming sequence - enables fine-tuning without hardware changes.
Block Lock™ EEPROM protection	Hardware-selectable lock of upper 256 bytes or full array - prevents accidental overwrite of critical boot or calibration data.
Fault Detection Register (FDR)	Volatile register (0xFF) logging cause of last reset (LV1F/LV2F/LV3F/WDF/MRF) - accelerates root-cause analysis in field failures.
Configurable power-on reset timeout	Four t_PURST options (50/200/400/800 ms) set via nonvolatile PUP bits - matches diverse processor initialization requirements.

Applications

Network Storage Controller	Rack-Mount Server PSU
Use Scenario: Monitoring 5 V main, 3.3 V auxiliary, and 1.8 V FPGA core rails in a disk array controller board. IC Role / Device Role / Timing Role: Triple-voltage supervisor providing coordinated reset assertion, early low-V_CC warning (LOWLINE), and EEPROM-stored configuration parameters. Use Value: Prevents corrupted firmware execution during multi-rail brownout; retains RAID configuration across power cycles using integrated 4Kbit EEPROM.	Use Scenario: Supervising primary 12 V DC-DC output, isolated 3.3 V management rail, and 1.2 V microcontroller core in modular server power supply. IC Role / Device Role / Timing Role: Independent voltage fail detection (V2FAIL/V3FAIL) feeding OR-gate reset tree; EEPROM stores calibration coefficients and fault logs. Use Value: Enables predictive power-fail response via V2FAIL interrupt before main rail collapse; eliminates external EEPROM and supervisor ICs.
Industrial PLC Backplane	Telecom Line Card
Use Scenario: Ensuring deterministic startup and runtime supervision of 24 V backplane, 5 V I/O, and 3.3 V communication processor in programmable logic controller. IC Role / Device Role / Timing Role: Power-on reset generator with 400 ms t_PURST, manual reset input (MR), and watchdog timer guarding firmware execution. Use Value: Guarantees clean processor initialization after hot-swap insertion; detects firmware lockup and forces recovery without operator intervention.	Use Scenario: Monitoring 48 V phantom power, 3.3 V PHY, and 1.8 V SerDes supply in carrier-grade Ethernet line card. IC Role / Device Role / Timing Role: Triple-threshold supervisor asserting RESET on any rail failure; EEPROM stores port-specific SFP+ module parameters. Use Value: Maintains service continuity by isolating faults to single rail; preserves optical transceiver settings across maintenance reboots.

Network Storage Controller

Rack-Mount Server PSU

Use Scenario: Monitoring 5 V main, 3.3 V auxiliary, and 1.8 V FPGA core rails in a disk array controller board.

IC Role / Device Role / Timing Role: Triple-voltage supervisor providing coordinated reset assertion, early low-V_CC warning (LOWLINE), and EEPROM-stored configuration parameters.

Use Value: Prevents corrupted firmware execution during multi-rail brownout; retains RAID configuration across power cycles using integrated 4Kbit EEPROM.

Use Scenario: Supervising primary 12 V DC-DC output, isolated 3.3 V management rail, and 1.2 V microcontroller core in modular server power supply.

IC Role / Device Role / Timing Role: Independent voltage fail detection (V2FAIL/V3FAIL) feeding OR-gate reset tree; EEPROM stores calibration coefficients and fault logs.

Use Value: Enables predictive power-fail response via V2FAIL interrupt before main rail collapse; eliminates external EEPROM and supervisor ICs.

Industrial PLC Backplane

Telecom Line Card

Use Scenario: Ensuring deterministic startup and runtime supervision of 24 V backplane, 5 V I/O, and 3.3 V communication processor in programmable logic controller.

IC Role / Device Role / Timing Role: Power-on reset generator with 400 ms t_PURST, manual reset input (MR), and watchdog timer guarding firmware execution.

Use Value: Guarantees clean processor initialization after hot-swap insertion; detects firmware lockup and forces recovery without operator intervention.

Use Scenario: Monitoring 48 V phantom power, 3.3 V PHY, and 1.8 V SerDes supply in carrier-grade Ethernet line card.

IC Role / Device Role / Timing Role: Triple-threshold supervisor asserting RESET on any rail failure; EEPROM stores port-specific SFP+ module parameters.

Use Value: Maintains service continuity by isolating faults to single rail; preserves optical transceiver settings across maintenance reboots.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MAX6816ESE+	Single-voltage supervisor (5 V only); no EEPROM; no V2MON/V3MON inputs; 200 ms fixed POR delay.	Lacks multi-rail monitoring and nonvolatile storage; suitable only for basic 5 V reset generation.	Select only if triple monitoring and EEPROM are unnecessary and cost is primary constraint.
TPS3808G33DBVR	Dual-voltage supervisor (3.3 V + adjustable second rail); no EEPROM; no manual reset input; 200 ms fixed POR.	Supports two rails only; requires external EEPROM for configuration storage; no MR pin integration.	Choose when supervising exactly two supplies and external memory is already present on board.

Compared with MAX6816ESE+ and TPS3808G33DBVR, the X40431S14-B uniquely integrates triple independent voltage monitoring, programmable thresholds, 4Kbit EEPROM, and manual reset in one 14-pin package - reducing BOM count and PCB area while enabling advanced power-fail diagnostics and configuration persistence.

Availability

X40431S14-B is available at Aetrix Electronics and suitable for network storage, industrial PLC, and telecom line card applications requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for X40431S14-B 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 was a fabless semiconductor company specializing in nonvolatile memory and power management ICs, acquired by Renesas Electronics in 2008. Its legacy products emphasize reliability, low power, and system integration.

The X4043x family was designed to consolidate power-on reset, watchdog, multi-rail voltage supervision, and EEPROM into a single chip for space-constrained embedded systems - targeting communications infrastructure and industrial control where board area and component count are critical.

FAQ

What voltage thresholds are factory-programmed in the X40431S14-B?

The X40431S14-B ships with V_TRIP1 = 4.55–4.65 V (for 5 V systems), V_TRIP2 = 2.85–2.95 V (for 3 V rails), and V_TRIP3 = 1.65–1.75 V (for 1.8 V domains). These values are laser-trimmed during production and remain stable over temperature and time unless reprogrammed via the I²C high-voltage sequence. The X40431S14-B datasheet specifies these ranges on page 2 under the "-B" variant row.

Can the X40431S14-B monitor voltages below 1 V?

No. The X40431S14-B minimum operational V_CC is 2.7 V, and its voltage monitors require input voltages above their respective V_TRIP thresholds to function correctly. While RESET remains valid down to V_CC = 1 V, the V2MON and V3MON comparators require their input voltages to exceed V_TRIP2 or V_TRIP3 (≥1.65 V) to produce valid outputs. The X40431S14-B cannot supervise sub-1 V rails such as 0.9 V CPU cores.

How does the X40431S14-B handle EEPROM write protection?

The X40431S14-B implements dual-layer EEPROM protection: hardware WP pin (pin 10) disables all writes when HIGH, and software-configurable Block Protect (BP) bit locks the upper 256 bytes (100h–1FFh) or entire array. Both mechanisms must be satisfied for a write to succeed. The X40431S14-B also includes power-up/power-down write inhibit circuitry that blocks writes during supply transients, preventing corruption during power cycling.

Is the X40431S14-B pin-compatible with other devices in the X4043x family?

Yes - all X4043x variants (X40430/X40431/X40434/X40435) share identical 14-pin SOIC/TSSOP pinouts and I²C command structure. The X40431S14-B differs only in factory-programmed V_TRIP values and RESET polarity (active-low), but pin functions, electrical characteristics, and register maps are fully compatible across the family. This allows direct substitution when voltage thresholds match system requirements.

What is the maximum I²C clock frequency supported by the X40431S14-B?

The X40431S14-B supports standard and fast-mode I²C operation up to 400 kHz, as confirmed in the "Serial Interface" section (page 10) of its datasheet. It meets I²C bus timing specifications including t_LOW, t_HIGH, and setup/hold times at this rate. The X40431S14-B does not support high-speed mode (3.4 MHz) and requires external pull-up resistors sized for 400 kHz operation on SDA/SCL lines.

X40431S14-B Specifications

Product attributes: Attribute value

Manufacturer:: Renesas

Series:: -

Package/Case:: 14-SOIC (0.154", 3.90mm Width)

Packaging:: Bulk

Product Status:: Obsolete

Programmable:: Not Verified

Type:: Multi-Voltage Supervisor

Number of Voltages Monitored:: 3

Voltage - Threshold:: 1.7V, 2.6V, 4.4V

Output:: Open Drain or Open Collector

Reset:: Active Low

Reset Timeout:: Adjustable/Selectable

Operating Temperature:: 0°C ~ 70°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 14-SOIC

X40431S14-B FAQ

1.How can I place an order for X40431S14-B through Aetrix?

Please submit a Request for Quotation (RFQ) for X40431S14-B on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for X40431S14-B reliable?

The price and inventory of X40431S14-B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for X40431S14-B is usually 5 days.

3.What payment methods are accepted for X40431S14-B?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for X40431S14-B transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for X40431S14-B?

X40431S14-B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your X40431S14-B order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for X40431S14-B?

For technical support, including X40431S14-B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your X40431S14-B requirements.

6.How does Aetrix verify that X40431S14-B is sourced from the original manufacturer or authorized distributors?

All X40431S14-B products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that X40431S14-B meets industry standards.

7.What is the process for return or replacement of X40431S14-B?

All X40431S14-B units undergo pre-shipment inspection (PSI). If there is an issue with X40431S14-B, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The X40431S14-B part is unused and in its original packaging.

Return procedure for X40431S14-B:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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