FT93C66A-USR-T EEPROM Memory IC Equivalent & Substitute Parts

Part Overview

The FT93C66A-USR-T is a 4Kbit non-volatile EEPROM memory IC manufactured by Fremont Micro Devices Ltd. It operates as a 3-wire serial interface device with a 2 MHz clock frequency, designed for applications requiring persistent data storage in compact form factors. The device is currently in active production status with 10,300 units in stock.

Substitute parts are identified when equivalent electrical specifications and mechanical compatibility are maintained across the critical parameters that define functional interchangeability within this EEPROM category.

Substiute Parts

FT93C66A-USR-T

Fremont Micro Devices LtdIn Stock: 10403FT93C66A-USR-T Datasheet

Current PartRFQ

AT93C66B-SSHM-T

Microchip TechnologyIn Stock: 22760AT93C66B-SSHM-T Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the FT93C66A-USR-T is determined by strict alignment of the following parameters:

• Memory capacity: 4Kbit
• Memory interface protocol: 3-Wire Serial
• Clock frequency: 2 MHz
• Package footprint: 8-SOIC (0.154", 3.90mm Width)
• Supply voltage compatibility: Overlapping operational range
• Operating temperature range: -40°C ~ 85°C
• Non-volatile EEPROM technology

The AT93C66B-SSHM-T from Microchip Technology meets all substitution criteria. Both devices share identical memory capacity, interface type, clock frequency, and package dimensions. The voltage supply range of the substitute (1.7V ~ 5.5V) encompasses the main part's range (1.8V ~ 5.5V), ensuring compatibility in standard applications.

Parameter Comparison

Engineering Selection Recommendations

The AT93C66B-SSHM-T is a direct functional equivalent to the FT93C66A-USR-T. Both devices are active production parts with ROHS3 compliance and identical regulatory status under REACH and ECCN classifications.

The substitute part offers performance advantages: a 5ms write cycle time compared to the main part's 10ms, and a marginally extended lower voltage limit (1.7V versus 1.8V). These characteristics make the AT93C66B-SSHM-T suitable for applications where faster write operations or lower voltage operation may be beneficial, while maintaining full compatibility with existing designs.

Packaging differences exist only in supplier designation: the main part is supplied in Tape & Reel (TR) format, while the substitute is available in Cut Tape (CT) and Digi-Reel® formats. Both use identical 8-SOIC package geometry.

Frequently Asked Questions (FAQ)

Q: Can the AT93C66B-SSHM-T replace the FT93C66A-USR-T in existing designs?

A: Yes. Both devices share identical memory capacity (4Kbit), interface protocol (3-Wire Serial), clock frequency (2 MHz), package footprint (8-SOIC), and operating temperature range (-40°C ~ 85°C). The substitute's voltage range (1.7V ~ 5.5V) is compatible with applications designed for the main part (1.8V ~ 5.5V).

Q: What are the key differences between these parts?

A: The primary differences are write cycle time (5ms for the substitute versus 10ms for the main part) and minimum supply voltage (1.7V versus 1.8V). The substitute offers faster write performance and broader voltage compatibility. Packaging format differs in supplier designation only.

Q: Are both parts RoHS compliant?

A: Yes. Both the FT93C66A-USR-T and AT93C66B-SSHM-T are ROHS3 compliant and REACH unaffected.

Q: Does the faster write cycle time of the substitute affect compatibility?

A: No. Faster write cycle time is a performance enhancement that does not affect functional compatibility. Designs specified for 10ms write cycles will operate correctly with the 5ms write cycle of the substitute.

Q: What packaging options are available for each part?

A: The FT93C66A-USR-T is supplied in Tape & Reel (TR) format. The AT93C66B-SSHM-T is available in Cut Tape (CT) and Digi-Reel® formats. Both use the same 8-SOIC package geometry.