93C66AT-I/MC EEPROM Memory IC Equivalent & Substitute Parts

Part Overview

The 93C66AT-I/MC is a 4Kbit non-volatile EEPROM memory IC manufactured by Microchip Technology, featuring Microwire serial interface protocol and operating at 2 MHz clock frequency. This component is designed for applications requiring persistent data storage in embedded systems, industrial controllers, and consumer electronics. The part is currently in active production status with verified programmability through DiGi-Electronics. Substitute parts may be required due to inventory constraints, packaging format preferences, or specific application voltage and timing requirements.

Substiute Parts

93C66AT-I/MC

Microchip TechnologyIn Stock: 108193C66AT-I/MC Datasheet

Current PartRFQ

93AA66AT-I/MC

Microchip TechnologyIn Stock: 171893AA66AT-I/MC Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The 93AA66AT-I/MC qualifies as a functional substitute for the 93C66AT-I/MC based on the following substitution criteria:

Matching Parameters:

• Memory capacity: 4Kbit
• Memory organization: 512 x 8
• Memory interface protocol: Microwire
• Clock frequency: 2 MHz
• Package type: 8-VFDFN Exposed Pad (8-DFN 2x3)
• Mounting type: Surface Mount
• Operating temperature range: -40°C to 85°C
• RoHS3 compliance
• Manufacturer: Microchip Technology

Differing Parameters:

• Supply voltage range: 93AA66AT-I/MC operates at 1.8V to 5.5V (wider range than 93C66AT-I/MC at 4.5V to 5.5V)
• Write cycle time: 93AA66AT-I/MC requires 6ms versus 2ms for 93C66AT-I/MC
• MSL rating: 93AA66AT-I/MC rated at MSL 1 (Unlimited) versus MSL 3 (168 Hours)
• Packaging format: 93AA66AT-I/MC available in Cut Tape (CT) & Digi-Reel® format

The 93AA66AT-I/MC is suitable as a substitute when the application can tolerate the extended write cycle time and does not require the faster 2ms write performance of the original part. The wider supply voltage range provides additional design flexibility for systems operating below 4.5V.

Parameter Comparison

Engineering Selection Recommendations

Both the 93C66AT-I/MC and 93AA66AT-I/MC are active production components from Microchip Technology with ROHS3 compliance and verified programmability. Selection between these parts depends on application-specific timing and voltage requirements:

Select 93C66AT-I/MC when:

• Write cycle time of 2ms is required for time-critical data storage operations
• Supply voltage is constrained to the 4.5V to 5.5V range
• Moisture sensitivity level 3 rating is acceptable for the application environment

Select 93AA66AT-I/MC when:

• Extended write cycle time of 6ms is acceptable
• Supply voltage flexibility below 4.5V is required (down to 1.8V minimum)
• Lower moisture sensitivity (MSL 1) is beneficial for storage or high-humidity environments
• Cut Tape or Digi-Reel® packaging format is preferred over standard Tape & Reel

Both parts maintain identical memory capacity, organization, interface protocol, clock frequency, package geometry, and operating temperature range, ensuring functional compatibility at the circuit board level when timing and voltage constraints are satisfied.

Frequently Asked Questions (FAQ)

Q: Can the 93AA66AT-I/MC directly replace the 93C66AT-I/MC in existing designs?

A: Direct replacement is possible if the application can accommodate the 6ms write cycle time instead of 2ms and if the supply voltage remains within the 4.5V to 5.5V range. The 93AA66AT-I/MC's wider voltage range (1.8V to 5.5V) provides additional flexibility for new designs but does not restrict operation at higher voltages.

Q: What is the impact of the different write cycle times?

A: The 93C66AT-I/MC completes write operations in 2ms, while the 93AA66AT-I/MC requires 6ms. Applications performing frequent sequential writes or requiring rapid data logging may experience timing differences. Applications with write operations spaced more than 6ms apart will not be affected.

Q: Are the package dimensions identical?

A: Yes. Both parts use the 8-VFDFN Exposed Pad package with 2x3mm dimensions. PCB footprints and reflow profiles are identical, allowing direct board-level substitution without layout modifications.

Q: What does MSL rating difference mean for component handling?

A: The 93C66AT-I/MC has MSL 3 rating, requiring storage at controlled humidity for up to 168 hours before soldering. The 93AA66AT-I/MC has MSL 1 rating with unlimited shelf life under standard conditions. This affects component storage and handling procedures but not electrical performance.

Q: Are both parts RoHS compliant?

A: Yes. Both the 93C66AT-I/MC and 93AA66AT-I/MC are ROHS3 compliant and REACH unaffected, meeting environmental regulatory requirements for industrial and consumer applications.