AT49F001NT-55PI Equivalent & Substitute Parts

Part Overview

The AT49F001NT-55PI is a 1Mbit parallel FLASH memory IC manufactured by Microchip Technology, housed in a 32-PDIP package with 55 ns access time. This device is classified as obsolete and is no longer in active production. Due to its obsolete status and limited availability for new designs, identifying functionally compatible substitute parts is essential for system maintenance, legacy product support, and component sourcing continuity.

Substiute Parts

AT49F001NT-55PI

Microchip TechnologyIn Stock: 1066AT49F001NT-55PI Datasheet

Current PartRFQ

SST39SF020A-70-4C-PHE

Microchip TechnologyIn Stock: 1837SST39SF020A-70-4C-PHE Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT49F001NT-55PI is determined by the following critical parameters:

• Memory Interface: Must be parallel to maintain pin-level compatibility
• Package Type: Must be 32-DIP (0.600", 15.24mm) for direct socket compatibility
• Supply Voltage Range: Must support 4.5V ~ 5.5V operation
• Memory Format: Must be FLASH technology, non-volatile
• Mounting Type: Must be Through Hole for PCB compatibility

The SST39SF020A-70-4C-PHE meets these substitution criteria. While it offers increased memory capacity (2Mbit vs. 1Mbit) and different access timing (70 ns vs. 55 ns), these differences do not prevent functional substitution in applications where the AT49F001NT-55PI is used, provided the system design accommodates the higher memory density and slightly slower access time.

Parameter Comparison

Engineering Selection Recommendations

The SST39SF020A-70-4C-PHE is the designated substitute for the AT49F001NT-55PI based on the following factors:

• Product Status: The AT49F001NT-55PI is obsolete, while the SST39SF020A-70-4C-PHE is active and maintains ongoing manufacturing support
• Compliance: The SST39SF020A-70-4C-PHE is ROHS3 compliant, whereas the AT49F001NT-55PI is non-compliant, making the substitute preferable for new designs and regulatory adherence
• Package Compatibility: Both devices use identical 32-DIP packaging, enabling direct socket replacement without PCB modifications
• Electrical Compatibility: Both operate within the same 4.5V ~ 5.5V supply voltage range and maintain parallel memory interface architecture
• Availability: The SST39SF020A-70-4C-PHE has confirmed inventory (1764 pcs) versus the AT49F001NT-55PI's limited stock (993 pcs)

Frequently Asked Questions (FAQ)

Q: Can the SST39SF020A-70-4C-PHE be used as a direct replacement for the AT49F001NT-55PI?

A: Yes, the SST39SF020A-70-4C-PHE is pin-compatible and functionally compatible. Both devices use 32-DIP packaging and parallel memory interface. The substitute operates within the same supply voltage range (4.5V ~ 5.5V) and maintains through-hole mounting compatibility.

Q: What are the differences in memory capacity between these parts?

A: The AT49F001NT-55PI provides 1Mbit (128K x 8) of storage, while the SST39SF020A-70-4C-PHE provides 2Mbit (256K x 8). The increased capacity of the substitute does not prevent substitution; however, system firmware or address decoding may require verification to ensure proper operation with the larger memory space.

Q: How do access times differ between these parts?

A: The AT49F001NT-55PI has a 55 ns access time, while the SST39SF020A-70-4C-PHE has a 70 ns access time. The substitute is 15 ns slower. For most legacy applications, this difference is not critical; however, timing-sensitive designs should verify that system timing margins accommodate the slower access time.

Q: What is the operating temperature range difference?

A: The AT49F001NT-55PI operates from -40°C to 85°C, while the SST39SF020A-70-4C-PHE operates from 0°C to 70°C. Applications requiring extended low-temperature operation below 0°C must verify that the substitute meets environmental requirements.

Q: Are there compliance differences between these parts?

A: Yes. The AT49F001NT-55PI is RoHS non-compliant, while the SST39SF020A-70-4C-PHE is ROHS3 compliant. For applications subject to RoHS regulations or environmental compliance requirements, the substitute is the appropriate choice.

Q: Can both parts be used interchangeably in the same PCB design?

A: Yes, both parts use identical 32-DIP (0.600", 15.24mm) packaging and through-hole mounting. No PCB modifications are required for physical substitution. Functional verification should confirm that firmware or system design accommodates the memory capacity and timing differences.