FT24C64A-USR-B EEPROM 64Kbit I2C Equivalent & Substitute Parts

Part Overview

The FT24C64A-USR-B is a 64Kbit EEPROM memory IC with I2C interface manufactured by Fremont Micro Devices Ltd. This device operates at 800 kHz clock frequency with 700 ns access time and supports supply voltages from 1.8V to 5.5V across the industrial temperature range of -40°C to 85°C. The part is discontinued at DiGi Electronics, making equivalent and substitute parts necessary for ongoing design support and production continuity.

Key Parameters

Parameter	FT24C64A-USR-B
Memory Size	64Kbit
Memory Organization	8K x 8
Memory Interface	I2C
Clock Frequency	800 kHz
Access Time	700 ns
Write Cycle Time	5 ms
Voltage Supply Range	1.8V ~ 5.5V
Operating Temperature	-40°C ~ 85°C
Package / Case	8-SOIC (0.154", 3.90mm Width)
Mounting Type	Surface Mount
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution eligibility for the FT24C64A-USR-B is determined by the following critical parameters:

Memory capacity: 64Kbit
Memory organization: 8K x 8
Interface protocol: I2C
Package type: 8-SOIC (0.154", 3.90mm Width)
Supply voltage compatibility: minimum 1.8V support
Operating temperature range: minimum -40°C to 85°C coverage

Substitute parts must maintain identical memory capacity, organization, and I2C interface. Package compatibility requires 8-SOIC form factor. Voltage supply range and operating temperature must equal or exceed the original specification. Clock frequency and access time variations are permissible provided the I2C protocol remains compatible.

Parameter Comparison

Part Number	Manufacturer	Memory Size	Clock Frequency	Access Time	Voltage Supply	Operating Temperature	Package	Product Status
FT24C64A-USR-B	Fremont Micro Devices Ltd	64Kbit	800 kHz	700 ns	1.8V ~ 5.5V	-40°C ~ 85°C	8-SOIC	Discontinued
FT24C64A-ESR-B	Fremont Micro Devices Ltd	64Kbit	1 MHz	500 ns	1.8V ~ 5.5V	-40°C ~ 85°C	8-SOIC	Active
24AA64-E/SN	Microchip Technology	64Kbit	400 kHz	900 ns	1.7V ~ 5.5V	-40°C ~ 125°C	8-SOIC	Active
24AA64-I/SN	Microchip Technology	64Kbit	400 kHz	900 ns	1.7V ~ 5.5V	-40°C ~ 85°C	8-SOIC	Active
24AA64F-I/SN	Microchip Technology	64Kbit	400 kHz	900 ns	1.7V ~ 5.5V	-40°C ~ 85°C	8-SOIC	Active
24AA64T-I/SNG	Microchip Technology	64Kbit	400 kHz	900 ns	1.7V ~ 5.5V	-40°C ~ 85°C	8-SOIC	Active
24FC64-I/SN	Microchip Technology	64Kbit	1 MHz	400 ns	1.7V ~ 5.5V	-40°C ~ 85°C	8-SOIC	Active
24FC64F-I/SN	Microchip Technology	64Kbit	1 MHz	400 ns	1.7V ~ 5.5V	-40°C ~ 85°C	8-SOIC	Active
24LC64F-I/SN	Microchip Technology	64Kbit	400 kHz	900 ns	2.5V ~ 5.5V	-40°C ~ 85°C	8-SOIC	Active
AT24C64D-SSHM-B	Microchip Technology	64Kbit	1 MHz	550 ns	1.7V ~ 5.5V	-40°C ~ 85°C	8-SOIC	Active
AT24CS64-SSHM-B	Microchip Technology	64Kbit	1 MHz	550 ns	1.7V ~ 5.5V	-40°C ~ 85°C	8-SOIC	Active

Engineering Selection Recommendations

Direct Replacement (Same Manufacturer): FT24C64A-ESR-B is the primary substitute from Fremont Micro Devices Ltd. This part maintains identical supply voltage range (1.8V ~ 5.5V) and operating temperature (-40°C ~ 85°C), with improved performance characteristics (1 MHz clock frequency, 500 ns access time). Product status is Active, ensuring long-term availability.

Cross-Manufacturer Substitutes (Microchip Technology): The 24FC64-I/SN and 24FC64F-I/SN devices provide 1 MHz operation with 400 ns access time, matching the performance tier of FT24C64A-ESR-B. Both are ROHS3 compliant and Active products. The 24FC64F-I/SN offers superior moisture sensitivity (MSL 1 vs. MSL 3), making it suitable for demanding environmental conditions.

Standard-Speed Alternatives: The 24AA64 series (24AA64-E/SN, 24AA64-I/SN, 24AA64F-I/SN, 24AA64T-I/SNG) operates at 400 kHz with 900 ns access time. These parts are suitable for applications where reduced clock frequency is acceptable. The 24AA64-E/SN supports extended operating temperature to 125°C.

Voltage-Constrained Applications: The 24LC64F-I/SN operates within 2.5V ~ 5.5V range and is not suitable for applications requiring 1.8V minimum supply voltage support.

All recommended substitutes maintain ROHS3 compliance and are currently Active products with established supply chains.

Frequently Asked Questions (FAQ)

Q: Can FT24C64A-USR-B be directly replaced with FT24C64A-ESR-B? A: Yes. Both parts share identical memory capacity (64Kbit), organization (8K x 8), I2C interface, package (8-SOIC), supply voltage range (1.8V ~ 5.5V), and operating temperature (-40°C ~ 85°C). FT24C64A-ESR-B offers improved performance with 1 MHz clock frequency and 500 ns access time.

Q: What is the difference between 24AA64 and 24FC64 series? A: The 24AA64 series operates at 400 kHz with 900 ns access time. The 24FC64 series operates at 1 MHz with 400 ns access time. Both maintain 64Kbit capacity and I2C interface. Selection depends on application timing requirements.

Q: Is 24LC64F-I/SN compatible with FT24C64A-USR-B? A: No. The 24LC64F-I/SN has a minimum supply voltage of 2.5V, whereas FT24C64A-USR-B supports 1.8V minimum. This part is unsuitable for low-voltage applications.

Q: Do all substitute parts use the same 8-SOIC package? A: Yes. All listed substitute parts use 8-SOIC (0.154", 3.90mm Width) package, ensuring mechanical and electrical compatibility on existing PCBs.

Q: Which substitute offers the best performance? A: The 24FC64-I/SN and 24FC64F-I/SN provide the fastest access time (400 ns) at 1 MHz clock frequency. The 24FC64F-I/SN additionally offers MSL 1 (Unlimited) moisture sensitivity.

Q: Are all substitutes ROHS3 compliant? A: Yes. All listed substitute parts carry ROHS3 compliance certification.

Q: What is the difference between tube and tape & reel packaging? A: Tube packaging is suitable for manual assembly and small-volume production. Tape & Reel (TR) packaging is optimized for automated pick-and-place assembly in high-volume manufacturing. Electrical and functional specifications remain identical.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message