Equivalent & Substitute Parts for 24LC21T/SN

Part Overview

The 24LC21T/SN is a 1Kbit EEPROM memory IC manufactured by Microchip Technology, featuring I2C interface operation at 400 kHz with 8-SOIC surface mount packaging. This device is designed for non-volatile data storage applications requiring low-power, serial communication in embedded systems. The part is currently in active production status with ROHS3 compliance and unlimited moisture sensitivity rating.

Substitute parts are necessary when the original 24LC21T/SN becomes unavailable due to supply constraints, when alternative packaging formats are required for manufacturing processes, or when enhanced operating temperature ranges or faster access times are needed for specific application requirements.

Substiute Parts

24LC21T/SN

Microchip TechnologyIn Stock: 704824LC21T/SN Datasheet

Current PartRFQ

24LC21/SN

Microchip TechnologyIn Stock: 241224LC21/SN Datasheet

DirectRFQ

24AA014HT-I/SN

Microchip TechnologyIn Stock: 224424AA014HT-I/SN Datasheet

MFR RecommendedRFQ

24AA01T-I/SN

Microchip TechnologyIn Stock: 1908924AA01T-I/SN Datasheet

MFR RecommendedRFQ

24LC014T-I/SN

Microchip TechnologyIn Stock: 195224LC014T-I/SN Datasheet

MFR RecommendedRFQ

24LC01BHT-I/SN

Microchip TechnologyIn Stock: 445024LC01BHT-I/SN Datasheet

MFR RecommendedRFQ

24LC01BT-E/SN

Microchip TechnologyIn Stock: 326924LC01BT-E/SN Datasheet

MFR RecommendedRFQ

24LC01BT-I/SN

Microchip TechnologyIn Stock: 1679824LC01BT-I/SN Datasheet

MFR RecommendedRFQ

24LC01BT/SN

Microchip TechnologyIn Stock: 440924LC01BT/SN Datasheet

MFR RecommendedRFQ

AT24CS01-SSHM-T

Microchip TechnologyIn Stock: 7533AT24CS01-SSHM-T Datasheet

MFR RecommendedRFQ

BR24C21FJ-E2

Rohm SemiconductorIn Stock: 2974BR24C21FJ-E2 Datasheet

MFR RecommendedRFQ

M24C01-RMN6TP

STMicroelectronicsIn Stock: 1915M24C01-RMN6TP Datasheet

MFR RecommendedRFQ

M24C01-WMN6P

STMicroelectronicsIn Stock: 10412M24C01-WMN6P Datasheet

MFR RecommendedRFQ

M24C01-WMN6TP

STMicroelectronicsIn Stock: 50609M24C01-WMN6TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 24LC21T/SN is determined by the following critical parameters:

Core Compatibility Requirements:

• Memory Size: 1Kbit (128 x 8 organization)
• Memory Interface: I2C serial protocol
• Package / Case: 8-SOIC form factor (0.154", 3.90mm Width)
• Mounting Type: Surface Mount
• Memory Format: EEPROM non-volatile technology

Performance Parameters (Allowable Variations):

• Clock Frequency: 400 kHz minimum (higher frequencies are acceptable)
• Access Time: 900 ns or faster (lower values are acceptable)
• Write Cycle Time: 10 ms or faster (lower values are acceptable)
• Voltage Supply Range: Must encompass or exceed 2.5V ~ 5.5V
• Operating Temperature: Must support at least 0°C ~ 70°C range

Compliance & Certification:

• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level: 1 (Unlimited) preferred; higher MSL values acceptable with process controls

Substitute parts meeting these criteria maintain functional and electrical compatibility while potentially offering improved performance characteristics or alternative packaging formats.

Parameter Comparison

Engineering Selection Recommendations

Direct Equivalent (Identical Specifications): The 24LC21/SN is the direct equivalent to 24LC21T/SN, differing only in packaging format (Tube versus Tape & Reel). Both maintain identical electrical specifications and performance characteristics. Selection between these two depends solely on manufacturing process requirements and packaging handling procedures.

Enhanced Performance Substitutes (Microchip Technology): The 24LC014T-I/SN, 24LC01BHT-I/SN, 24LC01BT-E/SN, 24LC01BT-I/SN, and 24LC01BT/SN all provide faster write cycle times (5 ms versus 10 ms) while maintaining 400 kHz I2C operation and 8-SOIC packaging. These parts are suitable for applications where reduced write latency improves system performance. The 24LC01BT-E/SN extends operating temperature to -40°C ~ 125°C, supporting extended industrial temperature ranges.

Extended Temperature Range Substitutes: The 24AA014HT-I/SN, 24AA01T-I/SN, 24LC014T-I/SN, 24LC01BHT-I/SN, 24LC01BT-E/SN, and 24LC01BT-I/SN all support -40°C ~ 85°C operating temperature, exceeding the 0°C ~ 70°C range of the original part. These are appropriate for applications requiring wider temperature operation.

Extended Voltage Range Substitute: The 24AA014HT-I/SN and 24AA01T-I/SN support 1.7V ~ 5.5V supply voltage, providing lower voltage operation capability compared to the 2.5V minimum of the original part. The AT24CS01-SSHM-T also supports 1.7V ~ 5.5V with enhanced 1 MHz clock frequency capability.

Alternative Manufacturer: The BR24C21FJ-E2 from Rohm Semiconductor provides equivalent 1Kbit I2C EEPROM functionality in 8-SOIC packaging with identical 400 kHz operation and 10 ms write cycle time. This part is suitable for applications requiring multi-source component qualification.

All substitute parts maintain ROHS3 compliance and are currently in active production status.

Frequently Asked Questions (FAQ)

Q: Can I use 24LC01BT-I/SN as a direct replacement for 24LC21T/SN?

A: Yes. Both parts share identical 1Kbit memory capacity, I2C 400 kHz interface, 8-SOIC packaging, and 2.5V ~ 5.5V supply voltage. The 24LC01BT-I/SN offers faster write cycle time (5 ms versus 10 ms) and extended operating temperature (-40°C ~ 85°C versus 0°C ~ 70°C), making it functionally compatible with improved performance characteristics.

Q: What is the difference between 24LC21T/SN and 24LC21/SN?

A: The primary difference is packaging format. The 24LC21T/SN is supplied in Tape & Reel (TR) format, while 24LC21/SN is supplied in Tube format. All electrical specifications, memory capacity, interface protocol, and performance parameters are identical. Selection depends on manufacturing equipment compatibility and assembly process requirements.

Q: Why would I choose AT24CS01-SSHM-T over other substitutes?

A: The AT24CS01-SSHM-T operates at 1 MHz clock frequency with 550 ns access time, providing significantly faster I2C communication compared to the standard 400 kHz operation of the original part. This substitute is appropriate for applications requiring higher data transfer rates while maintaining 1Kbit capacity and 8-SOIC form factor. It also supports extended 1.7V ~ 5.5V supply voltage range.

Q: Is BR24C21FJ-E2 from Rohm Semiconductor fully compatible?

A: The BR24C21FJ-E2 provides equivalent 1Kbit I2C EEPROM functionality in 8-SOIC packaging with matching 400 kHz operation and 10 ms write cycle time. It maintains ROHS3 compliance and supports -40°C ~ 85°C operating temperature. Compatibility is confirmed for applications requiring multi-source qualification or when Microchip Technology parts are unavailable.

Q: Can I use parts with lower voltage minimums like 24AA014HT-I/SN?

A: Yes. The 24AA014HT-I/SN supports 1.7V ~ 5.5V supply voltage, which encompasses the 2.5V ~ 5.5V range of the original part. This substitute is suitable for applications operating at the lower voltage end of the supply range and provides extended -40°C ~ 85°C temperature operation.

Q: What is the significance of write cycle time differences?

A: Write cycle time indicates the duration required to complete a single page write operation. The original 24LC21T/SN requires 10 ms per write cycle, while most substitutes (24LC01BHT-I/SN, 24LC01BT variants, 24AA01T-I/SN, 24AA014HT-I/SN) complete writes in 5 ms. Faster write cycles reduce overall system latency in applications performing frequent memory updates. This parameter does not affect read operations or I2C communication speed.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All substitute parts listed maintain ROHS3 compliance, meeting environmental and hazardous substance restrictions equivalent to the original 24LC21T/SN.