93LC66C-E/ST EEPROM Memory IC Equivalent & Substitute Parts

Part Overview

The 93LC66C-E/ST is a 4Kbit non-volatile EEPROM memory IC manufactured by Microchip Technology, featuring Microwire serial interface protocol. This component is designed for applications requiring persistent data storage with low power consumption and high reliability across industrial and commercial temperature ranges. The part is currently in active production status with verified programmability and full RoHS3 compliance.

Substitute parts are necessary to address supply chain availability, specific packaging requirements, temperature grade specifications, or automotive qualification needs while maintaining functional and electrical compatibility.

Substiute Parts

93LC66C-E/ST

Microchip TechnologyIn Stock: 119093LC66C-E/ST Datasheet

Current PartRFQ

M93C66-RDW3TP/K

STMicroelectronicsIn Stock: 2020M93C66-RDW3TP/K Datasheet

MFR RecommendedRFQ

M93C66-WDW6TP

STMicroelectronicsIn Stock: 105244M93C66-WDW6TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 93LC66C-E/ST is determined by the following critical parameters:

Mandatory Compatibility Parameters:

• Memory Size: 4Kbit (exact match required)
• Memory Format: EEPROM (exact match required)
• Memory Interface: Microwire (exact match required)
• Package / Case: 8-TSSOP (exact match required)
• Mounting Type: Surface Mount (exact match required)

Allowable Variation Parameters:

• Clock Frequency: 2 MHz to 3 MHz (lower frequency acceptable for timing-non-critical applications)
• Write Cycle Time: 5ms to 6ms (functional equivalence maintained)
• Voltage Supply Range: Minimum 1.8V acceptable if application operates within 2.5V ~ 5.5V envelope
• Operating Temperature: Extended range (-40°C ~ 125°C) or reduced range (-40°C ~ 85°C) depending on application requirements
• Packaging Format: Tube, Tape & Reel (TR), or Cut Tape (CT) & Digi-Reel® (logistics variation only)
• Certifications: Automotive qualification (AEC-Q100) adds capability without removing compatibility

Both identified substitute parts meet all mandatory compatibility parameters and are functionally equivalent to the 93LC66C-E/ST.

Parameter Comparison

Engineering Selection Recommendations

M93C66-RDW3TP/K Selection Criteria:

• Required for automotive applications demanding AEC-Q100 qualification
• Supports extended operating temperature range (-40°C ~ 125°C) matching the main part
• Lower clock frequency (2 MHz) acceptable for non-time-critical data access operations
• Extended voltage supply range (1.8V ~ 5.5V) provides additional design flexibility
• Tape & Reel packaging suitable for high-volume production environments

M93C66-WDW6TP Selection Criteria:

• Preferred for high-volume applications with standard commercial temperature requirements (-40°C ~ 85°C)
• Highest inventory availability (105,200 Pcs) ensures supply chain continuity
• Verified programmability status matches main part capability
• Cut Tape & Digi-Reel® packaging accommodates both manual and automated assembly workflows
• Voltage supply range (2.5V ~ 5.5V) matches main part specification exactly

Selection Constraints:

• M93C66-WDW6TP operating temperature maximum of 85°C is unsuitable for applications requiring full -40°C ~ 125°C range
• M93C66-RDW3TP/K programmability status is not verified; confirm compatibility with programming equipment before deployment
• Both substitutes operate at 2 MHz versus 3 MHz main part specification; verify timing margins in serial communication protocols

Frequently Asked Questions (FAQ)

Q: Can M93C66-WDW6TP replace 93LC66C-E/ST in all applications? A: No. M93C66-WDW6TP has a reduced operating temperature range (-40°C ~ 85°C) compared to the main part (-40°C ~ 125°C). Use this substitute only in applications operating within the 85°C maximum temperature limit.

Q: What is the functional difference between 2 MHz and 3 MHz clock frequency? A: The 2 MHz clock frequency in substitute parts reduces maximum serial data transfer rate. This is functionally equivalent for applications not requiring the higher 3 MHz throughput. Verify timing requirements in your Microwire protocol implementation before substitution.

Q: Are the substitute parts pin-compatible with 93LC66C-E/ST? A: Yes. Both substitute parts use identical 8-TSSOP package with matching pinout and electrical interface. Direct PCB footprint compatibility is confirmed.

Q: What does AEC-Q100 qualification mean for M93C66-RDW3TP/K? A: AEC-Q100 is an automotive industry standard qualification ensuring the component meets reliability, temperature cycling, and stress testing requirements for automotive applications. This qualification is not required for non-automotive use but does not restrict general-purpose applications.

Q: Why does M93C66-RDW3TP/K have "Not Verified" programmability status? A: Programmability verification status indicates whether DiGi-Electronics has tested the component with standard programming equipment. "Not Verified" does not indicate functional deficiency; it reflects testing scope. Confirm compatibility with your specific programming tools before production deployment.

Q: Can I use M93C66-RDW3TP/K in applications requiring -40°C ~ 125°C operation? A: Yes. M93C66-RDW3TP/K supports the full -40°C ~ 125°C temperature range, matching the main part specification and exceeding M93C66-WDW6TP capability.

Q: What packaging format should I select for my application? A: Tube packaging (main part) suits low-volume or manual assembly. Tape & Reel (M93C66-RDW3TP/K) and Cut Tape & Digi-Reel® (M93C66-WDW6TP) are optimized for automated pick-and-place assembly in production environments. Select based on assembly process requirements, not electrical performance.

Q: Are all three parts RoHS3 compliant? A: Yes. The main part 93LC66C-E/ST and both substitute parts M93C66-RDW3TP/K and M93C66-WDW6TP are ROHS3 compliant with unlimited moisture sensitivity level (MSL 1).