AT93C66W-10SC Equivalent & Substitute Parts

Part Overview

The AT93C66W-10SC is a 4Kbit EEPROM memory IC manufactured by Microchip Technology, featuring 3-Wire Serial interface operation at 2 MHz. This device is classified as obsolete, which necessitates identification of active equivalent components for new designs and production continuity. The part is packaged in 8-SOIC surface mount configuration with supply voltage range of 4.5V to 5.5V and operating temperature range of 0°C to 70°C.

Key Parameters

Parameter	Value
Memory Type	Non-Volatile EEPROM
Memory Size	4Kbit
Memory Organization	512 x 8, 256 x 16
Memory Interface	3-Wire Serial / Microwire
Clock Frequency	2 MHz
Write Cycle Time	10ms (AT93C66W-10SC)
Voltage Supply Range	4.5V ~ 5.5V (AT93C66W-10SC)
Operating Temperature	0°C ~ 70°C (AT93C66W-10SC)
Package / Case	8-SOIC (0.154", 3.90mm Width)
Mounting Type	Surface Mount
RoHS Status	RoHS non-compliant (AT93C66W-10SC)

Substitute Part Grouping Explanation

Substitution of the AT93C66W-10SC is based on the following critical parameters:

Memory Capacity: 4Kbit EEPROM
Memory Organization: 512 x 8 or 256 x 16 configuration
Serial Interface Compatibility: 3-Wire Serial (Microwire protocol compatible)
Clock Frequency: 2 MHz operation
Package Compatibility: 8-SOIC surface mount form factor
Electrical Compatibility: Pin-compatible interface and signal levels

The substitute parts M93C66-WMN6P and M93C66-WMN6TP, both manufactured by STMicroelectronics, meet these substitution criteria. Both devices implement the Microwire protocol, which is compatible with 3-Wire Serial interface requirements. The identical memory capacity, organization, clock frequency, and package ensure functional equivalence at the circuit level.

Parameter Comparison

Parameter	AT93C66W-10SC (Microchip)	M93C66-WMN6P (STMicroelectronics)	M93C66-WMN6TP (STMicroelectronics)
Memory Size	4Kbit	4Kbit	4Kbit
Memory Organization	512 x 8, 256 x 16	512 x 8, 256 x 16	512 x 8, 256 x 16
Memory Interface	3-Wire Serial	Microwire	Microwire
Clock Frequency	2 MHz	2 MHz	2 MHz
Write Cycle Time	10ms	5ms	5ms
Voltage Supply Range	4.5V ~ 5.5V	2.5V ~ 5.5V	2.5V ~ 5.5V
Operating Temperature	0°C ~ 70°C	-40°C ~ 85°C	-40°C ~ 85°C
Package / Case	8-SOIC	8-SOIC	8-SOIC
Product Status	Obsolete	Active	Active
RoHS Status	RoHS non-compliant	ROHS3 Compliant	ROHS3 Compliant
Packaging Option	Not specified	Tube	Cut Tape (CT) & Digi-Reel®

Engineering Selection Recommendations

The M93C66-WMN6P and M93C66-WMN6TP are functionally equivalent substitutes for the obsolete AT93C66W-10SC. Both STMicroelectronics parts offer active product status, ensuring long-term availability and supply chain continuity.

Key advantages of the substitute parts include:

Extended Operating Temperature Range: -40°C to 85°C versus 0°C to 70°C, providing broader environmental compatibility
Expanded Supply Voltage Range: 2.5V to 5.5V versus 4.5V to 5.5V, enabling operation in lower-voltage applications
Improved Write Performance: 5ms write cycle time versus 10ms, reducing programming duration
Regulatory Compliance: ROHS3 compliant status versus RoHS non-compliant, meeting modern environmental standards
Verified Programmability: Both parts are verified as programmable through DiGi-Electronics

Selection between M93C66-WMN6P (Tube packaging) and M93C66-WMN6TP (Cut Tape & Digi-Reel® packaging) depends on procurement and assembly requirements. M93C66-WMN6TP offers significantly higher inventory availability (35,100 pcs versus 1,543 pcs).

Frequently Asked Questions (FAQ)

Q: Are the M93C66-WMN6P and M93C66-WMN6TP truly interchangeable with the AT93C66W-10SC?

A: Yes. Both substitute parts share identical memory capacity (4Kbit), organization (512 x 8, 256 x 16), clock frequency (2 MHz), and 8-SOIC package. The Microwire interface is compatible with 3-Wire Serial protocol requirements. Pin configuration and signal levels are compatible for direct substitution.

Q: What is the difference between Microwire and 3-Wire Serial interface?

A: Microwire is a specific implementation of 3-Wire Serial communication protocol. The substitute parts use Microwire, which is functionally compatible with the original 3-Wire Serial interface of the AT93C66W-10SC.

Q: Why do the substitute parts have different voltage supply ranges?

A: The M93C66-WMN6P and M93C66-WMN6TP support a lower minimum supply voltage (2.5V) compared to the AT93C66W-10SC (4.5V minimum). This expanded range provides greater design flexibility and is not a limitation for applications requiring 4.5V to 5.5V operation.

Q: What is the significance of the extended operating temperature range in the substitute parts?

A: The substitute parts operate from -40°C to 85°C, compared to 0°C to 70°C for the original part. This extended range accommodates industrial and automotive applications requiring broader temperature performance without design modification.

Q: What does ROHS3 compliance mean for the substitute parts?

A: ROHS3 compliance indicates conformance to the Restriction of Hazardous Substances Directive, restricting use of specific hazardous materials. This certification is required for many modern applications and regulatory environments.

Q: Should I choose M93C66-WMN6P or M93C66-WMN6TP?

A: Both parts are electrically and functionally identical. Selection depends on packaging preference and availability. M93C66-WMN6TP in Cut Tape & Digi-Reel® format offers higher inventory availability (35,100 pcs) and is suitable for automated assembly. M93C66-WMN6P in Tube packaging may be preferred for manual assembly or lower-volume applications.

Q: Is the faster write cycle time (5ms vs 10ms) of the substitute parts a concern?

A: No. Faster write cycle time is an improvement that does not create compatibility issues. Applications designed for 10ms write cycles will function correctly with 5ms write cycles.

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