AT49F040-70PI Equivalent & Substitute Parts

Part Overview

The AT49F040-70PI is a 4Mbit parallel FLASH memory IC manufactured by Microchip Technology, housed in a 32-DIP package with 70 ns access time. This device is classified as obsolete, making equivalent substitute parts necessary for ongoing system support and new design implementations. The parallel interface and 512K x 8 memory organization define its functional role in legacy embedded systems and industrial applications.

Substiute Parts

AT49F040-70PI

Microchip TechnologyIn Stock: 2349AT49F040-70PI Datasheet

Current PartRFQ

SST39SF040-70-4C-PHE

Microchip TechnologyIn Stock: 1951SST39SF040-70-4C-PHE Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT49F040-70PI is determined by strict equivalence across the following parameters:

• Memory capacity: 4Mbit (512K x 8 organization)
• Interface type: Parallel
• Access time: 70 ns or faster
• Package: 32-DIP form factor
• Supply voltage: 4.5V ~ 5.5V compatibility
• Mounting: Through Hole

The SST39SF040-70-4C-PHE meets all substitution criteria. Both devices share identical memory capacity, organization, interface architecture, access time specification, package dimensions, voltage requirements, and mounting methodology. Functional compatibility is established through these electrical and mechanical parameters.

Parameter Comparison

Engineering Selection Recommendations

The SST39SF040-70-4C-PHE is a direct functional substitute for the AT49F040-70PI based on electrical and mechanical parameter equivalence. Selection between these devices depends on application requirements:

For legacy system maintenance and repair: The AT49F040-70PI remains suitable where existing inventory is available and operating temperature range (-40°C ~ 85°C) is required. Current inventory of 2260 units is available.

For new designs and long-term availability: The SST39SF040-70-4C-PHE is the recommended choice. This device is in active production status with 1847 units in stock, offers ROHS3 compliance for regulatory alignment, and provides faster write cycle time (20µs versus 50µs). The operating temperature range (0°C ~ 70°C) is suitable for standard industrial and commercial applications.

Both devices are manufactured by Microchip Technology, share identical ECCN (EAR99) and HTSUS (8542.32.0071) classifications, and are unaffected by REACH regulations.

Frequently Asked Questions (FAQ)

Q: Can the SST39SF040-70-4C-PHE directly replace the AT49F040-70PI in existing circuits?

A: Yes. Both devices are pin-compatible 32-DIP packages with identical memory capacity (4Mbit, 512K x 8), parallel interface, 70 ns access time, and 4.5V ~ 5.5V supply voltage. No circuit modifications are required for functional substitution.

Q: What is the difference in write cycle time between these devices?

A: The AT49F040-70PI has a write cycle time of 50µs, while the SST39SF040-70-4C-PHE operates at 20µs. The faster write cycle of the substitute part is compatible with systems designed for the original device and does not create compatibility issues.

Q: Are there temperature range limitations when substituting?

A: The AT49F040-70PI operates from -40°C ~ 85°C (TC), while the SST39SF040-70-4C-PHE operates from 0°C ~ 70°C (TA). For applications requiring extended low-temperature operation below 0°C or high-temperature operation above 70°C, the original AT49F040-70PI specification must be maintained. For standard industrial and commercial temperature ranges (0°C ~ 70°C), the substitute is fully compatible.

Q: What is the packaging difference?

A: Both devices use identical 32-DIP (0.600", 15.24mm) through-hole packaging. The SST39SF040-70-4C-PHE is supplied in tube packaging, while the AT49F040-70PI packaging specification was not provided. Both are suitable for standard PCB assembly processes.

Q: Why is the AT49F040-70PI classified as obsolete?

A: The AT49F040-70PI has reached end-of-life status in Microchip Technology's product portfolio. The SST39SF040-70-4C-PHE, part of the active SST39 MPF™ series, represents the current production equivalent for this memory capacity and interface type.

Q: Are there compliance differences between these parts?

A: The SST39SF040-70-4C-PHE is ROHS3 compliant, while the AT49F040-70PI is RoHS non-compliant. Both are REACH unaffected and carry the same ECCN classification. For new designs subject to RoHS regulations, the SST39SF040-70-4C-PHE is the appropriate selection.