AT49F040-90TC Equivalent & Substitute Parts

Part Overview

The AT49F040-90TC is a 4Mbit parallel FLASH memory IC manufactured by Microchip Technology, packaged in a 32-TSOP surface mount configuration with 90 ns access time. This device is classified as obsolete, making equivalent substitute parts necessary for ongoing system support, maintenance, and new design implementations where legacy compatibility is required.

Substiute Parts

AT49F040-90TC

Microchip TechnologyIn Stock: 2029AT49F040-90TC Datasheet

Current PartRFQ

MX29F040CTC-90G

MacronixIn Stock: 2570MX29F040CTC-90G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the AT49F040-90TC are qualified based on the following critical parameters:

• Memory capacity: 4Mbit
• Memory organization: 512K x 8 configuration
• Interface type: Parallel
• Access time: 90 ns maximum
• Supply voltage range: 4.5V ~ 5.5V
• Package: 32-TFSOP surface mount
• Mounting compatibility: Surface mount technology

The MX29F040CTC-90G from Macronix meets all electrical and mechanical substitution criteria. Additional compatible alternatives include MX29F040CTI-70G and SST39SF040-70-4C-WHE, which maintain identical memory specifications and package compatibility.

Parameter Comparison

Engineering Selection Recommendations

The MX29F040CTC-90G is the primary substitute for the AT49F040-90TC. This part maintains full electrical and mechanical compatibility while offering the advantage of active product status and ROHS3 compliance. Both devices share identical memory capacity, organization, interface type, access time, supply voltage, operating temperature range, and 32-TFSOP package specifications.

The AT49F040-90TC is classified as obsolete, whereas the MX29F040CTC-90G is actively manufactured and supported. For applications requiring regulatory compliance, the MX29F040CTC-90G provides ROHS3 certification, whereas the original part is non-compliant.

Secondary alternatives MX29F040CTI-70G and SST39SF040-70-4C-WHE maintain the same core memory specifications and package compatibility, providing additional sourcing options.

Frequently Asked Questions (FAQ)

Q: What makes the MX29F040CTC-90G a valid substitute for the AT49F040-90TC?

A: Both devices share identical memory capacity (4Mbit), organization (512K x 8), parallel interface, 90 ns access time, 4.5V–5.5V supply voltage, 0°C–70°C operating temperature range, and 32-TFSOP package. These parameters define functional and mechanical compatibility.

Q: Are there differences in write cycle time between the main part and substitute?

A: The AT49F040-90TC specifies 50µs write cycle time, while the MX29F040CTC-90G specifies 90ns. Both values are provided in the device specifications and do not prevent substitution for parallel FLASH memory applications.

Q: Does the MX29F040CTC-90G fit the same PCB footprint?

A: Yes. Both the AT49F040-90TC and MX29F040CTC-90G use the 32-TFSOP package with 0.724" width and 18.40mm dimensions, ensuring identical PCB footprint compatibility.

Q: What is the significance of product status in substitution?

A: The AT49F040-90TC is obsolete, meaning Microchip no longer manufactures or supports this device. The MX29F040CTC-90G is active, ensuring ongoing availability, technical support, and compliance with current manufacturing standards.

Q: Is the MX29F040CTC-90G RoHS compliant?

A: Yes. The MX29F040CTC-90G is ROHS3 compliant, whereas the AT49F040-90TC is non-compliant. This is relevant for applications subject to RoHS regulations.