Renesas X40435V14I-A

Overview

X40435V14I-A from Xicor is a triple-voltage CPU supervisor IC with integrated 4Kbit EEPROM, watchdog timer, and fault detection register. It monitors V_CC (V1), V2MON, and V3MON at factory-programmed thresholds (4.55–4.65V, 1.25–1.35V, 3.05–3.15V), asserts active-low RESET and WDO outputs, and supports I²C-compatible 2-wire interface up to 400kHz - deployed in network storage controllers for power-fail warning and secure configuration retention.

For engineers reviewing the X40435V14I-A datasheet, X40435V14I-A pinout, X40435V14I-A application, or X40435V14I-A equivalent, key selection criteria include triple independent voltage monitoring range (0.9V to 5V), programmable reset timeout (50/200/400/800ms), nonvolatile watchdog interval selection (25ms/200ms/1.4s/off), EEPROM block-lock protection, and 14-pin SOIC/TSSOP package compatibility.

Technical Context

The X40435V14I-A implements three independent voltage comparators - V1 (V_CC) monitored with reset assertion down to 1V, V2 (V2MON) and V3 (V3MON) powered independently of V_CC for unregulated supply tracking - each feeding dedicated open-drain fail outputs (V2FAIL, V3FAIL) and contributing to fault detection register status. Its watchdog logic responds to SDA/SCL activity using a four-instruction restart sequence (START–SCL LOW–SCL HIGH–STOP).

Power-on reset timing is controlled by nonvolatile PUP1/PUP0 bits (factory default: 200ms), while VTRIP thresholds are reprogrammable via high-voltage pulse on WDO pin and I²C command sequence - enabling field calibration without hardware changes. The 4Kbit EEPROM uses Direct Write™ cells (100k write cycles, 100-year data retention) with 16-byte page write and software write protection (WP pin + Block Lock™).

Key Specifications

Pinout & Package

Package: 14-lead SOIC (width 3.9mm) and TSSOP (width 4.4mm), RoHS-compliant, moisture sensitivity level 3.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6361KA29+T and TPS3808G33DBVR, the X40435V14I-A uniquely integrates triple independent voltage monitoring, EEPROM-based fault logging, and field-reprogrammable thresholds - making it the only option for systems requiring coordinated multi-rail power sequencing with persistent event history.

Availability

X40435V14I-A is available at Aetrix Electronics and suitable for network storage, industrial PLC backplanes, and telecom line cards requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for X40435V14I-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 2001 and later integrated into Renesas Electronics.

The X4043x family was designed to consolidate power-on reset, watchdog, multi-rail voltage monitoring, and secure EEPROM into a single chip - targeting cost-sensitive, space-constrained embedded systems in communications and industrial automation.

FAQ

What voltage thresholds are factory-programmed in the X40435V14I-A?

The X40435V14I-A ships with VTRIP1 = 4.55–4.65V (V_CC), VTRIP2 = 1.25–1.35V (V2MON), and VTRIP3 = 3.05–3.15V (V3MON). These values are stored in nonvolatile trim cells and remain stable over temperature and time unless reprogrammed using the high-voltage WDO pulse sequence specified in the datasheet. The X40435V14I-A supports field adjustment of any threshold to meet custom system requirements.

Does the X40435V14I-A support I²C communication at 400kHz?

Yes, the X40435V14I-A supports standard- and fast-mode I²C up to 400kHz on its SDA/SCL pins. It uses a 7-bit slave address (A0h) with software-addressable registers including EEPROM array, Control Register (1FFh), and Fault Detection Register (0FFh). The X40435V14I-A implements full acknowledge protocol and supports both byte and 16-byte page writes with internal address incrementing.

How does the watchdog timer in the X40435V14I-A get reset?

The X40435V14I-A watchdog timer is reset by a specific four-step I²C sequence: START condition, SCL toggled LOW then HIGH, followed by STOP - executed on the SDA/SCL bus. This sequence must occur within the selected timeout interval (25ms/200ms/1.4s/off). The X40435V14I-A does not respond to generic I²C traffic; only this exact pattern restarts the timer and prevents WDO assertion.

Can the EEPROM in the X40435V14I-A be protected against accidental writes?

Yes, the X40435V14I-A provides three layers of EEPROM write protection: hardware WP pin (HIGH disables all writes), volatile Write Enable Latch (WEL), and nonvolatile Block Protect (BP) bit that locks the upper 256 bytes (100h–1FFh). The X40435V14I-A requires sequential WEL and RWEL bit setting before modifying BP or watchdog settings - preventing unintended configuration changes during normal operation.

What is the function of the LOWLINE pin on the X40435V14I-A?

The LOWLINE pin on the X40435V14I-A is a CMOS output that goes LOW earlier than the RESET signal when V_CC falls below VTRIP1 - providing an early warning of impending brownout. Unlike RESET, LOWLINE has no power-up delay (t_PURST) and transitions immediately, enabling host firmware to initiate graceful shutdown, save state, or throttle peripherals before full reset occurs. The X40435V14I-A uses this pin for predictive power management in mission-critical systems.