Microchip 24LC21A/P EEPROM 1Kbit I2C Memory IC Equivalent & Substitute Parts

Part Overview

The Microchip 24LC21A/P is a 1Kbit EEPROM memory IC utilizing I2C serial interface protocol with 400 kHz clock frequency. This non-volatile memory device is designed for applications requiring persistent data storage in embedded systems, industrial controllers, and consumer electronics. The part is currently in active production status with verified programmability and full RoHS3 compliance. Equivalent and substitute parts are identified when component availability is limited, supply chain disruptions occur, or design flexibility permits alternative device selection within specified electrical and mechanical parameters.

Substiute Parts

24LC21A/P

Microchip TechnologyIn Stock: 2355124LC21A/P Datasheet

Current PartRFQ

24AA01-I/P

Microchip TechnologyIn Stock: 251224AA01-I/P Datasheet

MFR RecommendedRFQ

24LC01B-I/P

Microchip TechnologyIn Stock: 1031124LC01B-I/P Datasheet

MFR RecommendedRFQ

24LC01B/P

Microchip TechnologyIn Stock: 400224LC01B/P Datasheet

MFR RecommendedRFQ

24LC21/P

Microchip TechnologyIn Stock: 388424LC21/P Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 24LC21A/P is determined by strict alignment of core electrical and mechanical parameters. All substitute parts must maintain identical memory capacity (1Kbit), memory organization (128 x 8), interface protocol (I2C), and clock frequency (400 kHz). Package compatibility requires 8-DIP through-hole mounting in 0.300" (7.62mm) form factor. Voltage supply range and operating temperature specifications define the operational envelope; substitutes with expanded or equivalent ranges are acceptable. Access time and write cycle time variations do not preclude substitution provided the substitute meets or exceeds performance requirements for the application. All identified substitutes are manufactured by Microchip Technology and maintain active product status with RoHS3 compliance.

Parameter Comparison

Engineering Selection Recommendations

All identified substitute parts maintain active product status and full RoHS3 compliance, ensuring regulatory alignment with the original 24LC21A/P specification. The 24LC21/P represents a parametric equivalent with identical electrical performance characteristics, including 900 ns access time and 10 ms write cycle time, differing only in packaging designation (tube vs. standard). The 24LC01B-I/P and 24LC01B/P variants offer extended operating temperature ranges (-40°C to 85°C) and faster write cycle times (5 ms), suitable for applications requiring enhanced thermal performance. The 24AA01-I/P provides the widest voltage supply range (1.7V to 5.5V) and extended temperature specification, accommodating low-power and industrial environments. Selection between substitutes depends on application-specific requirements for operating temperature range, supply voltage constraints, and write cycle performance. All parts maintain identical I2C interface protocol, memory capacity, and physical package dimensions, ensuring direct functional compatibility in circuit board designs.

Frequently Asked Questions (FAQ)

Q: Can the 24LC01B-I/P replace the 24LC21A/P in all applications?

A: The 24LC01B-I/P is functionally compatible for I2C EEPROM applications requiring 1Kbit storage capacity. Both devices share identical memory organization (128 x 8), interface protocol (I2C 400 kHz), and 8-DIP package form factor. The 24LC01B-I/P offers faster write cycle time (5 ms vs. 10 ms) and extended operating temperature range (-40°C to 85°C vs. 0°C to 70°C). Substitution is valid when application operating temperature and write cycle performance requirements align with the substitute device specifications.

Q: What is the difference between 24LC01B/P and 24LC01B-I/P?

A: Both devices are electrically and functionally identical 1Kbit I2C EEPROM memory ICs with 400 kHz clock frequency, 8-DIP package, and identical electrical parameters. The designation difference reflects packaging and supplier classification. Both maintain RoHS3 compliance and active product status. Selection between these variants depends on packaging availability and supply chain considerations rather than electrical performance.

Q: Is the 24AA01-I/P suitable for low-voltage applications?

A: The 24AA01-I/P supports voltage supply range of 1.7V to 5.5V, compared to the 24LC21A/P specification of 2.5V to 5.5V. This extended lower voltage limit makes the 24AA01-I/P suitable for low-power applications operating below 2.5V. All other electrical parameters, including 1Kbit memory capacity, I2C interface, and 400 kHz clock frequency, remain identical to the main part.

Q: Do all substitute parts use the same 8-DIP package?

A: All identified substitute parts utilize the 8-DIP (0.300", 7.62mm) through-hole package, ensuring mechanical compatibility with circuit board designs specified for the 24LC21A/P. No package conversion or board redesign is required for substitution.

Q: Are there temperature-related constraints when selecting a substitute?

A: The 24LC21A/P operates within 0°C to 70°C temperature range. Substitutes 24LC01B-I/P and 24AA01-I/P extend this range to -40°C to 85°C, providing broader thermal capability. The 24LC01B/P and 24LC21/P maintain the original 0°C to 70°C specification. Selection should align with the application's actual operating temperature requirements.