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

onsemi CAT1027WI-25

Name: CAT1027WI-25
Brand: onsemi
SKU: CAT1027WI-25
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: CAT1027WI-25

Manufacturer:: onsemi

Category:: Supervisors

Package:: 8-SOIC (0.154", 3.90mm Width)

Datasheet:: CAT1027WI-25.pdf

Description:: CAT1027 - DUAL VOLTAGE SUPERVISO

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Product details

Overview

CAT1027WI-25 from Catalyst Semiconductor is a dual-voltage supervisory IC with integrated 2k-bit I²C EEPROM, designed for microcontroller-based systems requiring brown-out protection and system reset control. It features a precision 2.55–2.70 V reset threshold, 1.6 s watchdog timer, auxiliary voltage monitor (VSENSE), and operates from 3.0 V to 5.5 V. Used in industrial power management and embedded controllers where reliable power-up sequencing and data retention are critical.

For engineers reviewing the CAT1027WI-25 datasheet, pinout, applications, or equivalent options, this page delivers verified functional identity, confirmed reset timing (tPURST = 200 ms), watchdog timeout (1.6 s), EEPROM endurance (1M cycles), and package-specific pin mapping for SOIC-8 (W package, Industrial temp).

Technical Context

The CAT1027WI-25 integrates a precision V_CC monitor with fixed 2.55–2.70 V reset threshold, an auxiliary comparator referenced to 1.25 V on VSENSE, and a watchdog timer activated via WDI input. Its open-drain RESET output remains valid down to V_CC = 1.0 V, ensuring robust reset assertion during brownout.

It implements a 400 kHz I²C interface with 16-byte page write buffer, built-in write protection triggered by V_CC monitoring, and supports immediate, random, and sequential read modes. The device guarantees 100-year data retention and 1,000,000 program/erase cycles for its 2k-bit EEPROM array.

Key Specifications

Parameter	Value and Actual Design Meaning
Reset Threshold	2.55–2.70 V - precisely targets 2.5 V nominal systems; ensures deterministic reset activation before logic corruption.
Watchdog Timeout	1.6 s - provides fail-safe recovery from software hangs without external timing components.
I²C Speed	400 kHz - enables fast configuration and EEPROM access compatible with standard Fast-mode controllers.
EEPROM Capacity	2 kbit (256 × 8) - stores calibration data, device ID, or configuration parameters in space-constrained designs.
Supply Range	3.0 V to 5.5 V - supports both 3.3 V and 5 V microcontroller domains without level-shifting.
Operating Temp	−40 °C to +85 °C - qualified for industrial environments including factory automation and metering.
Data Retention	100 years - ensures long-term reliability of stored settings across product lifetime.

Pinout & Package

Package: 8-pin SOIC (W suffix), 150-mil width, 1.27 mm pitch, 1.75 mm max height, RoHS-compliant lead-free finish.

Pin/Terminal	Circuit Role	Design Meaning
VCC	Power supply input	Primary supply rail (3.0–5.5 V); powers all internal circuits including EEPROM and reset logic.
RESET	Active-low open-drain reset output	Drives low during V_CC undervoltage or watchdog timeout; requires external pull-up for logic-high state.
SCL	I²C clock input	Master-generated serial clock; synchronizes all EEPROM read/write transfers at up to 400 kHz.
SDA	I²C bidirectional data line	Open-drain bus line shared with other I²C devices; supports ACK polling and multi-byte page writes.
VLOW	Auxiliary voltage monitor output	Open-drain signal asserted low when VSENSE < 1.25 V; used for secondary supply fault detection or power-fail interrupt.
VSENSE	Auxiliary voltage monitor input	High-impedance comparator input; monitors second supply via resistor divider; tied to VCC if unused.
WDI	Watchdog timer interrupt input	Edge-triggered input; reset timer on any transition; failure to toggle within 1.6 s forces RESET assertion.
VSS	Ground reference	System ground return for all analog and digital functions; must be low-impedance connection.

Key Features

Feature	Design Value
Integrated 2k-bit I²C EEPROM	16-byte page write buffer enables efficient bulk storage of configuration data without host-side buffering.
Programmable reset threshold	Five factory-set options (including 2.55–2.70 V for CAT1027WI-25) eliminate external resistor networks for V_CC monitoring.
Watchdog timer with WDI input	1.6 s timeout provides autonomous system recovery-no firmware overhead required to maintain timer refresh.
VSENSE auxiliary monitor	1.25 V reference allows flexible monitoring of secondary rails (e.g., analog sensors, RTCs) using high-value resistive dividers.
Write protection during power anomaly	V_CC-sensing circuit disables EEPROM writes below reset threshold, preventing corruption during brownout or power-up.

Applications

Industrial PLC I/O Module	Smart Energy Meter
Use Scenario: Monitors main 3.3 V MCU supply and isolated 2.5 V sensor rail in DIN-rail mounted controllers. IC Role / Device Role / Timing Role: Dual-supply supervisor with watchdog ensures deterministic boot and runtime recovery; EEPROM stores calibration coefficients. Use Value: Prevents erratic behavior during grid-induced brownouts; eliminates need for discrete reset IC + external EEPROM.	Use Scenario: Secures metrology parameter storage and detects backup battery voltage drop in ANSI C12.20-compliant meters. IC Role / Device Role / Timing Role: VSENSE monitors 3.0 V backup rail; RESET asserts before RTC data loss; EEPROM retains tariff tables and billing logs. Use Value: Guarantees 100-year data integrity and failsafe reset at 2.55–2.70 V threshold-aligned with metering accuracy requirements.
Medical Infusion Pump Controller	Automotive Body Control Module (BCM)
Use Scenario: Supervises 5 V main MCU and 3.3 V motor driver supply in Class II medical devices with strict safety margins. IC Role / Device Role / Timing Role: Precision reset (2.55–2.70 V) prevents unsafe operation during transient dips; watchdog enforces firmware liveness checks. Use Value: Meets IEC 62304 SW safety requirements via hardware-enforced reset and memory protection.	Use Scenario: Manages power sequencing for LIN transceiver and microcontroller in 12 V automotive subsystems with wide input range. IC Role / Device Role / Timing Role: VCC monitor tracks regulated 5 V domain; VSENSE watches unregulated 12 V rail for early power-fail warning. Use Value: Enables graceful shutdown and nonvolatile event logging before battery disconnect-critical for diagnostic traceability.

Industrial PLC I/O Module

Smart Energy Meter

Use Scenario: Monitors main 3.3 V MCU supply and isolated 2.5 V sensor rail in DIN-rail mounted controllers.

IC Role / Device Role / Timing Role: Dual-supply supervisor with watchdog ensures deterministic boot and runtime recovery; EEPROM stores calibration coefficients.

Use Value: Prevents erratic behavior during grid-induced brownouts; eliminates need for discrete reset IC + external EEPROM.

Use Scenario: Secures metrology parameter storage and detects backup battery voltage drop in ANSI C12.20-compliant meters.

IC Role / Device Role / Timing Role: VSENSE monitors 3.0 V backup rail; RESET asserts before RTC data loss; EEPROM retains tariff tables and billing logs.

Use Value: Guarantees 100-year data integrity and failsafe reset at 2.55–2.70 V threshold-aligned with metering accuracy requirements.

Medical Infusion Pump Controller

Automotive Body Control Module (BCM)

Use Scenario: Supervises 5 V main MCU and 3.3 V motor driver supply in Class II medical devices with strict safety margins.

IC Role / Device Role / Timing Role: Precision reset (2.55–2.70 V) prevents unsafe operation during transient dips; watchdog enforces firmware liveness checks.

Use Value: Meets IEC 62304 SW safety requirements via hardware-enforced reset and memory protection.

Use Scenario: Manages power sequencing for LIN transceiver and microcontroller in 12 V automotive subsystems with wide input range.

IC Role / Device Role / Timing Role: VCC monitor tracks regulated 5 V domain; VSENSE watches unregulated 12 V rail for early power-fail warning.

Use Value: Enables graceful shutdown and nonvolatile event logging before battery disconnect-critical for diagnostic traceability.

Equivalent & Alternatives

The following parts are listed as comparable options for similar supervisory + EEPROM applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MAX6361KA25+T	No integrated EEPROM; standalone 2.5 V reset IC with manual reset and watchdog; no I²C interface.	Requires external EEPROM for configuration storage; suitable only when memory is handled separately.	Select when system already includes I²C EEPROM or when lower BOM count is less critical than guaranteed automotive qualification.
MCP809T-250I/OT	2.5 V reset IC with manual reset only; no watchdog, no VSENSE, no EEPROM; SOT-23-5 package.	Lacks auxiliary monitoring and data storage; limited to basic reset functionality in space-constrained designs.	Choose for cost-sensitive, low-complexity applications where watchdog and dual-supply monitoring are unnecessary.

Compared with MAX6361KA25+T and MCP809T-250I/OT, CAT1027WI-25 uniquely combines 2.55–2.70 V supervision, 1.6 s watchdog, VSENSE monitoring, and 2k-bit I²C EEPROM in one SOIC-8 package-reducing component count, PCB area, and firmware complexity for integrated power management.

Availability

CAT1027WI-25 is available at Aetrix Electronics and suitable for industrial automation, smart metering, and medical electronics requiring stable component supply, long-life data retention, and deterministic power-on reset behavior.

Supply support for CAT1027WI-25 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

Catalyst Semiconductor was a fabless analog/mixed-signal IC designer specializing in power management and interface solutions before acquisition by ON Semiconductor in 2010.

The CAT1026/CAT1027 family was engineered for microcontroller-based systems needing consolidated voltage supervision, EEPROM storage, and watchdog protection-targeting industrial, metering, and embedded control applications with stringent reliability requirements.

FAQ

What is the exact reset threshold voltage range for CAT1027WI-25?

The CAT1027WI-25 has a factory-trimmed reset threshold of 2.55 V minimum to 2.70 V maximum, specified over temperature and supply conditions. This range corresponds to the "-25" suffix per the ordering guide and ensures reliable reset assertion in 2.5 V nominal systems before logic instability occurs. The threshold is internally generated and does not require external components.

Does CAT1027WI-25 support both active-high and active-low reset outputs?

No. Unlike the CAT1026, the CAT1027WI-25 provides only a single active-low open-drain RESET output. It does not include the complementary active-high reset output found on CAT1026 variants. The RESET pin serves as both output and manual reset input when driven low externally.

How does the watchdog timer in CAT1027WI-25 function, and what is its timeout period?

The CAT1027WI-25 watchdog timer resets the system after 1.6 seconds if no edge transition occurs on the WDI pin. Any high-to-low or low-to-high transition clears the timer. While RESET is asserted, the timer remains cleared and does not count. This provides deterministic recovery from firmware lockups without software intervention.

Can CAT1027WI-25's VSENSE pin monitor voltages below 1.25 V?

No. The internal reference for the VSENSE comparator is fixed at 1.25 V (typical). VLOW asserts low only when VSENSE falls *below* this threshold. To monitor lower voltages (e.g., 1.0 V), an external resistor divider must scale the target voltage upward so that 1.0 V maps to ≥1.25 V at VSENSE.

What EEPROM write endurance and data retention does CAT1027WI-25 guarantee?

CAT1027WI-25 guarantees 1,000,000 program/erase cycles and 100 years of data retention for its 2k-bit EEPROM, per MIL-STD-883 testing methods. These values are characterized and specified across the full industrial temperature range (−40 °C to +85 °C) and apply to all memory locations.

CAT1027WI-25 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: CAT1027

Package/Case:: 8-SOIC (0.154", 3.90mm Width)

Packaging:: Bulk

Product Status:: Obsolete

Programmable:: Not Verified

Type:: Multi-Voltage Supervisor

Number of Voltages Monitored:: 2

Voltage - Threshold:: 2.55V, 2.7V

Output:: Open Drain or Open Collector

Reset:: Active Low

Reset Timeout:: 130ms Minimum

Operating Temperature:: -40°C ~ 85°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

CAT1027WI-25 FAQ

1.How can I place an order for CAT1027WI-25 through Aetrix?

Please submit a Request for Quotation (RFQ) for CAT1027WI-25 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 CAT1027WI-25 reliable?

The price and inventory of CAT1027WI-25 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CAT1027WI-25 is usually 5 days.

3.What payment methods are accepted for CAT1027WI-25?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CAT1027WI-25 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for CAT1027WI-25?

CAT1027WI-25 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your CAT1027WI-25 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 CAT1027WI-25?

For technical support, including CAT1027WI-25 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CAT1027WI-25 requirements.

6.How does Aetrix verify that CAT1027WI-25 is sourced from the original manufacturer or authorized distributors?

All CAT1027WI-25 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 CAT1027WI-25 meets industry standards.

7.What is the process for return or replacement of CAT1027WI-25?

All CAT1027WI-25 units undergo pre-shipment inspection (PSI). If there is an issue with CAT1027WI-25, 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 CAT1027WI-25 part is unused and in its original packaging.

Return procedure for CAT1027WI-25:

1.Submit a request within 90 days.

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

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