93LC66A/ST EEPROM Memory IC Equivalent & Substitute Parts

Part Overview

The 93LC66A/ST is a 4Kbit EEPROM memory integrated circuit manufactured by Microchip Technology, utilizing Microwire serial interface protocol. This non-volatile memory device operates at 2 MHz clock frequency with a 512 x 8 memory organization and is housed in an 8-TSSOP surface mount package. The part is currently in active production status and ROHS3 compliant. Substitute parts are identified when equivalent electrical specifications and mechanical compatibility are maintained across the allowed parameter range for this EEPROM category.

Substiute Parts

93LC66A/ST

Microchip TechnologyIn Stock: 103493LC66A/ST Datasheet

Current PartRFQ

93AA66A-I/ST

Microchip TechnologyIn Stock: 173593AA66A-I/ST Datasheet

MFR RecommendedRFQ

93LC66A-I/ST

Microchip TechnologyIn Stock: 225693LC66A-I/ST Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 93LC66A/ST are qualified based on the following criteria:

Core Electrical Compatibility:

• Memory size: 4Kbit (512 x 8 organization)
• Memory interface: Microwire protocol
• Clock frequency: 2 MHz
• Write cycle time: 6ms
• Package type: 8-TSSOP with identical physical dimensions

Allowed Parameter Variations:

• Voltage supply range: Substitutes must support the main part's 2.5V ~ 5.5V range as a minimum
• Operating temperature: Substitutes may extend the temperature range beyond the main part's 0°C ~ 70°C specification
• Programmable verification status: Substitutes may differ in DiGi-Electronics programmable verification

Non-Substitutable Parameters:

• Memory capacity, organization, and interface protocol
• Package form factor and pin configuration
• RoHS and REACH compliance status

Parameter Comparison

Engineering Selection Recommendations

93LC66A/ST (Main Part):

• Specified for 0°C ~ 70°C operating temperature range
• DiGi-Electronics programmable verification confirmed
• 1024 pcs inventory available
• Suitable for standard industrial temperature applications

93AA66A-I/ST:

• Extended operating temperature range: -40°C ~ 85°C
• Extended voltage supply range: 1.8V ~ 5.5V (supports lower voltage operation)
• DiGi-Electronics programmable verification not verified
• 1662 pcs inventory available
• Suitable for extended temperature and lower voltage applications

93LC66A-I/ST:

• Extended operating temperature range: -40°C ~ 85°C
• Voltage supply range matches main part: 2.5V ~ 5.5V
• DiGi-Electronics programmable verification confirmed
• 2200 pcs inventory available
• Suitable for extended temperature applications with verified programmability

All substitute parts maintain ROHS3 compliance and REACH unaffected status consistent with the main part.

Frequently Asked Questions (FAQ)

Q: Can 93AA66A-I/ST replace 93LC66A/ST in all applications?

A: 93AA66A-I/ST is electrically compatible with identical memory capacity, organization, interface, and clock frequency. The extended operating temperature range (-40°C ~ 85°C) and lower voltage floor (1.8V) provide broader operational capability. However, DiGi-Electronics programmable verification is not confirmed for this part. Verify programmability requirements for your specific application.

Q: What is the difference between 93LC66A/ST and 93LC66A-I/ST?

A: Both parts share identical electrical specifications including voltage supply range (2.5V ~ 5.5V) and memory parameters. The primary difference is operating temperature range: 93LC66A/ST operates 0°C ~ 70°C, while 93LC66A-I/ST operates -40°C ~ 85°C. Both have confirmed DiGi-Electronics programmable verification and ROHS3 compliance.

Q: Are all substitute parts pin-compatible?

A: Yes. All listed substitute parts use the 8-TSSOP package with identical physical dimensions (0.173", 4.40mm width) and surface mount configuration, ensuring direct pin-for-pin compatibility.

Q: Which substitute part offers the broadest operating range?

A: 93AA66A-I/ST provides the broadest operating envelope with voltage supply range of 1.8V ~ 5.5V and operating temperature range of -40°C ~ 85°C.

Q: Are all parts RoHS compliant?

A: Yes. The main part and all substitute parts are ROHS3 compliant and REACH unaffected.