25LC640XT-I/ST EEPROM Memory IC Equivalent & Substitute Parts

Part Overview

The 25LC640XT-I/ST is a 64Kbit Serial Peripheral Interface (SPI) EEPROM memory IC manufactured by Microchip Technology. This non-volatile memory device operates at 2 MHz clock frequency with a supply voltage range of 2.5V to 5.5V and is housed in an 8-TSSOP surface mount package. The part is currently active in production and ROHS3 compliant. Equivalent and substitute parts are identified based on matching memory capacity, interface protocol, package type, and electrical operating parameters to ensure functional interchangeability in circuit applications.

Key Parameters

Parameter	Value
Memory Size	64Kbit
Memory Organization	8K x 8
Memory Interface	SPI
Clock Frequency	2 MHz
Write Cycle Time	5ms
Voltage Supply Range	2.5V ~ 5.5V
Operating Temperature	-40°C ~ 85°C
Package Type	8-TSSOP (0.173", 4.40mm Width)
Mounting Type	Surface Mount
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitution eligibility for the 25LC640XT-I/ST is determined by the following critical parameters:

Memory Capacity: 64Kbit (8K x 8 organization) is mandatory for functional equivalence
Interface Protocol: SPI interface is required for circuit compatibility
Package Configuration: 8-TSSOP surface mount package with 0.173" width (4.40mm) ensures mechanical and electrical pin compatibility
Supply Voltage Range: Minimum 2.5V support is required; parts with extended lower voltage ranges (1.8V or 1.7V) are compatible but not required
Clock Frequency: The 25LC640XT-I/ST operates at 2 MHz; substitute parts with equal or higher clock frequencies (10 MHz, 16 MHz, 20 MHz) are functionally compatible
Write Cycle Time: 5ms or faster write cycles ensure compatibility
Operating Temperature Range: Parts rated for -40°C to 85°C or extended ranges (-40°C to 105°C, 125°C, or 145°C) are compatible
Product Status: Active production status ensures availability and supply chain reliability

Substitute parts are grouped by manufacturer and performance tier while maintaining these core compatibility parameters.

Parameter Comparison

Part Number	Manufacturer	Memory Size	Clock Frequency (MHz)	Voltage Supply (V)	Operating Temp (°C)	Write Cycle (ms)	Package	Packaging Type	Product Status
25LC640XT-I/ST	Microchip Technology	64Kbit	2	2.5 ~ 5.5	-40 ~ 85	5	8-TSSOP	Tape & Reel	Active
25LC640X-I/ST	Microchip Technology	64Kbit	2	2.5 ~ 5.5	-40 ~ 85	5	8-TSSOP	Tube	Active
25AA640AT-I/ST	Microchip Technology	64Kbit	10	1.8 ~ 5.5	-40 ~ 85	5	8-TSSOP	Tape & Reel	Active
25LC640AT-E/ST	Microchip Technology	64Kbit	10	2.5 ~ 5.5	-40 ~ 125	5	8-TSSOP	Cut Tape & Digi-Reel	Active
25LC640AT-I/ST	Microchip Technology	64Kbit	10	2.5 ~ 5.5	-40 ~ 85	5	8-TSSOP	Cut Tape & Digi-Reel	Active
AT25640B-XHL-T	Microchip Technology	64Kbit	20	1.8 ~ 5.5	-40 ~ 85	5	8-TSSOP	Cut Tape & Digi-Reel	Active
CAV25640YE-GT3	onsemi	64Kbit	10	2.5 ~ 5.5	-40 ~ 125	5	8-TSSOP	Tape & Reel	Active
M95640-DFDW6TP	STMicroelectronics	64Kbit	20	1.7 ~ 5.5	-40 ~ 85	5	8-TSSOP	Cut Tape & Digi-Reel	Active
M95640-DRDW3TP/K	STMicroelectronics	64Kbit	20	1.8 ~ 5.5	-40 ~ 125	4	8-TSSOP	Cut Tape & Digi-Reel	Active
M95640-DRDW8TP/K	STMicroelectronics	64Kbit	16	1.8 ~ 5.5	-40 ~ 105	4	8-TSSOP	Tape & Reel	Active
M95640-DWDW4TP/K	STMicroelectronics	64Kbit	20	2.5 ~ 5.5	-40 ~ 145	4	8-TSSOP	Cut Tape & Digi-Reel	Active

Engineering Selection Recommendations

Microchip Technology 25LC640 Series: The 25LC640X-I/ST provides direct substitution with identical electrical specifications and differs only in packaging format (Tube vs. Tape & Reel). The 25AA640AT-I/ST and 25LC640AT variants offer higher clock frequencies (10 MHz) while maintaining backward compatibility. The 25LC640AT-E/ST extends operating temperature to 125°C for elevated temperature applications. The AT25640B-XHL-T provides the highest clock frequency (20 MHz) with extended low-voltage support (1.8V minimum).

onsemi CAV25640YE-GT3: This part meets automotive qualification (AEC-Q100) and extends operating temperature to 125°C, suitable for automotive and industrial applications requiring enhanced temperature performance.

STMicroelectronics M95640 Series: The M95640-DRDW3TP/K and M95640-DRDW8TP/K variants include automotive qualification (AEC-Q100) with extended temperature ranges and faster write cycles (4ms). The M95640-DWDW4TP/K offers the widest operating temperature range (-40°C to 145°C) for extreme temperature environments. All M95640 variants support lower minimum supply voltages (1.7V to 1.8V) compared to the primary part.

All substitute parts maintain ROHS3 compliance and active production status. Selection should be based on specific application requirements for clock frequency, temperature range, voltage supply constraints, and automotive qualification needs.

Frequently Asked Questions (FAQ)

Q: Can I use a substitute part with a higher clock frequency than the 25LC640XT-I/ST?

A: Yes. The 25LC640XT-I/ST operates at 2 MHz. Substitute parts with 10 MHz, 16 MHz, or 20 MHz clock frequencies are functionally compatible because higher clock speeds are backward compatible with lower-speed circuit designs. The substitute part will operate correctly in applications designed for 2 MHz operation.

Q: What is the difference between Tape & Reel and Cut Tape & Digi-Reel packaging?

A: Both packaging types contain the same 8-TSSOP component. Tape & Reel packaging is continuous reel format suitable for high-volume automated assembly. Cut Tape & Digi-Reel packaging provides smaller quantities on cut tape segments. Selection depends on production volume and assembly equipment compatibility, not electrical performance.

Q: Are automotive-qualified parts (AEC-Q100) compatible with non-automotive applications?

A: Yes. Automotive-qualified parts such as CAV25640YE-GT3 and M95640-DRDW3TP/K meet stricter reliability and temperature testing standards. These parts are fully compatible with non-automotive applications and provide enhanced reliability margins.

Q: Can I substitute a part with a lower minimum supply voltage?

A: Yes. Parts with lower minimum supply voltages (1.7V or 1.8V) are compatible with applications designed for 2.5V minimum. The substitute part will operate across the full voltage range of the original design and beyond.

Q: What is the significance of write cycle time differences (5ms vs. 4ms)?

A: Write cycle time specifies the duration required to complete a single page write operation. Faster write cycles (4ms) are compatible with applications designed for 5ms cycles. The substitute part will complete write operations faster than specified, providing performance improvement without compatibility issues.

Q: Are all substitute parts in active production?

A: Yes. All listed substitute parts maintain active production status, ensuring supply chain availability and long-term support equivalent to the primary 25LC640XT-I/ST part.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message