24LC21A-I/P EEPROM Memory IC Equivalent & Substitute Parts

Part Overview

The 24LC21A-I/P is a 1Kbit EEPROM memory integrated circuit manufactured by Microchip Technology, designed for I2C serial communication applications operating at 400 kHz. This non-volatile memory device is housed in an 8-DIP through-hole package and operates across a supply voltage range of 2.5V to 5.5V with an operating temperature range of -40°C to 85°C. The device is ROHS3 compliant and carries an active product status. Equivalent and substitute parts are identified based on matching memory capacity, interface protocol, package type, and electrical operating parameters to ensure functional interchangeability in circuit designs.

Substiute Parts

24LC21A-I/P

Microchip TechnologyIn Stock: 114724LC21A-I/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

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 24LC21A-I/P are qualified based on the following critical parameters that determine functional interchangeability:

Core Matching Criteria:

• Memory capacity: 1Kbit
• Memory organization: 128 x 8 bit structure
• Serial interface: I2C protocol
• Clock frequency: 400 kHz operation
• Package format: 8-DIP through-hole configuration
• Mounting compatibility: Through-hole PCB assembly
• Operating temperature range: -40°C to 85°C
• RoHS compliance: ROHS3 Compliant status

The 24AA01-I/P and 24LC01B-I/P meet all core matching criteria. Variations in access time and write cycle time do not prevent substitution, as these parameters represent performance characteristics rather than functional compatibility requirements. Both substitute parts maintain identical memory capacity, interface protocol, package type, and thermal operating range as the primary part.

Parameter Comparison

Engineering Selection Recommendations

All three parts—24LC21A-I/P, 24AA01-I/P, and 24LC01B-I/P—carry active product status and maintain ROHS3 compliance. Selection between these parts is determined by specific application requirements:

24LC21A-I/P is the primary reference part with the fastest access time of 900 ns and operates within a supply voltage range of 2.5V to 5.5V.

24AA01-I/P offers the widest supply voltage range (1.7V to 5.5V), making it suitable for low-power applications. Access time is 3500 ns with a 5 ms write cycle time.

24LC01B-I/P maintains the same supply voltage range as the primary part (2.5V to 5.5V) with an access time of 4.6 µs and a 5 ms write cycle time.

All parts are verified as programmable by DiGi-Electronics and carry identical REACH and ECCN classifications. Selection should be based on the specific voltage supply requirements and access time performance needed for the target application.

Frequently Asked Questions (FAQ)

Q: Can 24AA01-I/P replace 24LC21A-I/P in all applications?

A: The 24AA01-I/P is functionally compatible as a substitute. However, it has a slower access time (3500 ns versus 900 ns) and a lower minimum supply voltage (1.7V versus 2.5V). Verify that your circuit design accommodates the slower access time and operates within the 1.7V to 5.5V supply range if using this substitute.

Q: What is the difference between 24LC01B-I/P and 24LC21A-I/P?

A: Both parts share identical memory capacity, interface protocol, package type, and supply voltage range (2.5V to 5.5V). The primary difference is access time: 24LC21A-I/P operates at 900 ns while 24LC01B-I/P operates at 4.6 µs. Both are suitable substitutes where access time performance is not a critical constraint.

Q: Are all substitute parts available in the same 8-DIP package?

A: Yes. All three parts—24LC21A-I/P, 24AA01-I/P, and 24LC01B-I/P—are packaged in 8-DIP (0.300", 7.62mm) through-hole configuration, ensuring identical PCB footprint and mounting compatibility.

Q: Do these parts require different circuit design considerations?

A: All parts operate on the same I2C protocol at 400 kHz and share the same operating temperature range (-40°C to 85°C). The primary design consideration is supply voltage: if your circuit operates below 2.5V, only 24AA01-I/P is suitable. For standard 2.5V to 5.5V applications, all three parts are interchangeable.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All three parts carry ROHS3 compliance certification and are suitable for applications requiring RoHS compliance.