CAT1021LI42

Supervisors Overview

The CAT1021LI42 is a voltage supervisory circuit manufactured by onsemi, designed for CPU systems. It integrates a 2k-bit serial EEPROM with manual reset and watchdog timer capabilities. The device operates within a supply voltage range of 2.7 V to 5.5 V. It features a threshold voltage of 4.2 V, with an under-voltage threshold of 4.25 V and an over-voltage threshold of 4.5 V. The component supports through-hole installation in an 8-pin PDIP package. It functions across a temperature range of -40°C to +85°C, drawing a typical operating current of 3 mA.

Supervisors Feature Summary

• Integrates a 2k-bit serial EEPROM memory with built-in inadvertent write protection via the WP pin.
• Provides system power supervision with manual reset functionality and a watchdog timer.
• Supports standard 5 V, 3.3 V, and 3 V system architectures with precise voltage monitoring.

Supervisors Applications

• Microcontroller-based system power management
• CPU voltage supervision and reset generation
• Data retention applications requiring non-volatile memory

Supervisors Procurement Notes

Verify end-of-life status before procurement as this component may be discontinued. Confirm RoHS compliance details directly with the manufacturer or authorized distributors. Ensure the specific suffix matches the required package type and temperature grade. Request official datasheets and PCN documents to validate current manufacturing specifications and any potential obsolescence notices prior to finalizing orders.

Supervisors Selection Notes

Select this part when a combined supervisory circuit and EEPROM solution is required for microcontroller systems. Choose based on the specific threshold voltage needed, such as 4.2 V for standard logic levels. Consider the through-hole PDIP package for prototyping or high-reliability assembly. Verify that the integrated watchdog timer and manual reset features align with the target system's fault recovery requirements.

Supervisors Part Context

This component belongs to the CAT1021 series of supervisory circuits from onsemi. The series provides complete memory and supervisory solutions for microcontroller-based systems. Other variants in the family include different threshold voltages, packages such as SOIC and TSSOP, and options without watchdog timers. The CAT1021LI42 specifically denotes the through-hole DIP package variant with a 4.2 V threshold.

Supervisors Replacement Considerations

Consult the official onsemi product selector guide for direct replacements. Potential substitutes include other CAT1021 variants with matching threshold voltages and package types. Cross-reference with CAT1022 or CAT1023 series parts if I2C interface compatibility is required instead of SPI. Verify electrical parameters and pinout compatibility before substitution.