Renesas X40420V14-A

Overview

X40420V14-A from Xicor is a dual-voltage supervisor IC with integrated CPU reset controller, watchdog timer, battery backup switch, and 4kbit EEPROM. It provides 4.6V/2.9V dual threshold detection, programmable V_TRIP2 down to 0.9V, 200ms power-on reset timeout (factory default), and 5mA–50mA V_OUT switching capability - used in network server power management to maintain SRAM data during AC loss.

For engineers reviewing the X40420V14-A datasheet, X40420V14-A pinout, X40420V14-A application, or X40420V14-A equivalent, key selection considerations include its active-HIGH RESET output, 14-pin SOIC/TSSOP package, dual-supply monitoring architecture, and nonvolatile watchdog and reset timeout configuration via I²C.

Technical Context

The X40420V14-A implements two independent voltage monitors: V_TRIP1 fixed at 4.6V ±1% and V_TRIP2 fixed at 2.9V ±1.7%, both with valid reset assertion down to V_CC = 1V. Its reset logic asserts active-HIGH RESET for t_PURST = 200ms on power-up and during brownout.

It integrates a 2-wire (I²C-compatible) interface operating up to 400kHz, supporting EEPROM read/write, control register access (WD1/WD0, PUP1/PUP0, BP), and fault detection register (FDR) reads - all using slave address A0h and special preambles (1011) for register space.

Key Specifications

Pinout & Package

Package: 14-lead SOIC (width 3.9mm) and TSSOP (width 4.4mm), both RoHS-compliant and rated for –40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6361KA29+T and TPS3823-33DBVR, the X40420V14-A uniquely integrates dual-voltage monitoring, active-HIGH reset, battery-backed V_OUT, and 4kbit EEPROM in one 14-pin package - eliminating four discrete components and enabling compact, high-reliability power management in space-constrained embedded systems.

Availability

X40420V14-A is available at Aetrix Electronics and suitable for network servers, industrial PLCs, and disk array controllers requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for X40420V14-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 X40420/X40421 product line was designed for embedded systems requiring consolidated power supervision, reliable reset generation, and on-chip data storage - targeting telecom infrastructure, industrial automation, and computing platforms where board space and BOM count are critical.

FAQ

What is the reset polarity and output type of the X40420V14-A?

The X40420V14-A features an active-HIGH RESET output implemented as an open-drain driver. This allows direct interfacing with processors requiring high-asserted reset signals and supports wired-OR configurations with other reset sources. The output remains HIGH during V_CC brownout, power-up delay, or manual reset assertion - ensuring robust system initialization. Unlike the X40421 variant, the X40420V14-A does not provide active-LOW reset functionality.

How is the V_TRIP2 threshold configured on the X40420V14-A?

The X40420V14-A ships with factory-programmed V_TRIP2 = 2.9V ±1.7%, and this value is fixed for the -A suffix variant. While the datasheet describes a high-voltage programming procedure for custom V_TRIP2 adjustment, that method applies only to blank or uncommitted devices - not to the pre-configured X40420V14-A. Therefore, the V_TRIP2 threshold on X40420V14-A is non-adjustable in-circuit and must be used as specified: 2.9V nominal with ±1.7% tolerance.

Does the X40420V14-A support I²C communication at standard speeds?

Yes, the X40420V14-A supports standard-mode I²C communication up to 400kHz on its SDA and SCL pins. It uses slave address A0h and implements full protocol compliance including START/STOP conditions, ACK/NACK handshaking, and 9-bit addressing for EEPROM and register access. The interface enables reading the Fault Detection Register, configuring watchdog timeout and power-up delay, and performing byte/page writes to the 4kbit EEPROM - all without requiring additional level-shifting or protocol translation.

What is the function of the BATT-ON pin on the X40420V14-A?

The BATT-ON pin on the X40420V14-A is a CMOS output that goes HIGH when V_OUT is sourced from V_BATT (i.e., during main power failure), and LOW when V_OUT is sourced from V_CC. Its primary purpose is to drive an external PNP pass transistor, allowing higher current delivery (>50mA) to system loads during normal operation while automatically disabling that path during battery backup mode. This ensures efficient power delivery without compromising SRAM retention during outages.

Can the EEPROM in the X40420V14-A be protected against accidental writes?

Yes, the X40420V14-A includes multiple hardware and software write protection mechanisms for its 4kbit EEPROM. Hardware protection is provided by the WP pin: when pulled HIGH, it disables all writes to EEPROM and registers. Software protection is implemented via the Block Protect (BP) bit in the control register, which locks the upper 256 bytes (addresses 100h–1FFh) against modification. Additionally, power-up/power-down circuitry prevents writes during unstable supply conditions - collectively ensuring data integrity in mission-critical applications.