FM93CS46N EEPROM 1Kbit Microwire Equivalent & Substitute Parts

Part Overview

The FM93CS46N is a 1Kbit EEPROM memory IC with Microwire interface manufactured by onsemi. This device is classified as obsolete, which necessitates identification of equivalent substitute components for ongoing system support and new designs. The FM93CS46N operates at 1 MHz clock frequency with a 10ms write cycle time and is packaged in an 8-DIP through-hole configuration. Due to its obsolete status, sourcing alternatives from active product lines is essential for procurement continuity.

Substiute Parts

FM93CS46N

onsemiIn Stock: 861FM93CS46N Datasheet

Current PartRFQ

93C46A-I/P

Microchip TechnologyIn Stock: 240293C46A-I/P Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the FM93CS46N are identified based on the following critical parameters that determine functional compatibility:

Core Compatibility Criteria:

• Memory Size: 1Kbit (mandatory match)
• Memory Format: EEPROM (mandatory match)
• Memory Interface: Microwire (mandatory match)
• Package Type: 8-DIP through-hole (mandatory match for PCB compatibility)
• Voltage Supply Range: 4.5V ~ 5.5V (mandatory match)

Secondary Considerations:

• Clock Frequency: The substitute may operate at equal or higher frequency
• Write Cycle Time: The substitute may have equal or faster write performance
• Operating Temperature Range: The substitute may support equal or extended temperature range
• Product Status: Active product status preferred for long-term availability
• RoHS Compliance: Modern substitutes should meet current regulatory requirements

The 93C46A-I/P from Microchip Technology meets all mandatory compatibility criteria while offering improved specifications in clock frequency, write cycle time, operating temperature range, and RoHS compliance status.

Parameter Comparison

Engineering Selection Recommendations

The 93C46A-I/P is a direct functional substitute for the FM93CS46N based on matching core electrical and mechanical specifications. Selection of the 93C46A-I/P provides the following advantages:

Product Availability: The 93C46A-I/P maintains active product status with Microchip Technology, ensuring long-term procurement availability compared to the obsolete FM93CS46N.

Regulatory Compliance: The 93C46A-I/P is ROHS3 compliant, meeting current environmental and regulatory requirements, whereas the FM93CS46N is non-compliant.

Performance Characteristics: The 93C46A-I/P operates at 2 MHz clock frequency with a 2ms write cycle time, providing improved performance margins over the FM93CS46N specifications of 1 MHz and 10ms respectively.

Temperature Range: The 93C46A-I/P supports an extended operating temperature range of -40°C to 85°C, compared to the FM93CS46N range of 0°C to 70°C, enabling use in broader environmental conditions.

Package Compatibility: Both devices utilize identical 8-DIP through-hole packaging, ensuring direct PCB layout compatibility without redesign requirements.

Frequently Asked Questions (FAQ)

Q: Can the 93C46A-I/P directly replace the FM93CS46N without PCB modifications?

A: Yes. Both devices use identical 8-DIP (0.300", 7.62mm) through-hole packaging with the same pin configuration for Microwire interface signals. Direct pin-for-pin substitution is possible without PCB layout changes.

Q: Are there any electrical compatibility concerns when substituting the 93C46A-I/P for the FM93CS46N?

A: No. Both devices operate within the same 4.5V to 5.5V supply voltage range and maintain Microwire interface protocol compatibility. The 93C46A-I/P's higher clock frequency and faster write cycle time are backward compatible with system designs specified for the FM93CS46N.

Q: What is the significance of the different memory organization between the two parts (64 x 16 versus 128 x 8)?

A: Both configurations represent 1Kbit total memory capacity. The memory organization difference reflects internal architecture variations between manufacturers but does not affect functional compatibility for Microwire interface operation. The Microwire protocol handles data access transparently regardless of internal organization.

Q: Why is RoHS compliance important for this substitution?

A: RoHS compliance indicates adherence to current environmental and hazardous substance restrictions. The 93C46A-I/P's ROHS3 compliance ensures compatibility with modern supply chain requirements and regulatory standards, whereas the FM93CS46N's non-compliance may create procurement and end-product certification issues.

Q: Does the extended temperature range of the 93C46A-I/P (-40°C to 85°C) affect system design?

A: The extended temperature range of the 93C46A-I/P provides additional operational margin and does not require system design modifications. Systems designed for the FM93CS46N's 0°C to 70°C range will operate within the 93C46A-I/P's specification envelope without changes.

Q: Is the improved write cycle time (2ms versus 10ms) of the 93C46A-I/P a concern for timing-critical applications?

A: No. The faster write cycle time of the 93C46A-I/P is a performance improvement that does not create compatibility issues. Systems designed with timing margins for the FM93CS46N's 10ms write cycle will experience improved performance with the 93C46A-I/P without requiring firmware or timing adjustments.