AT45DB321D-MU-SL954 Equivalent & Substitute Parts

Part Overview

The AT45DB321D-MU-SL954 is a 32Mbit Serial Peripheral Interface (SPI) FLASH memory IC manufactured by Renesas Electronics Corporation, operating at 66 MHz with a supply voltage range of 2.7V to 3.6V. This component is packaged in an 8-VDFN (6x5) form factor with exposed pad and is classified as obsolete. Due to its obsolete status and limited availability, equivalent substitute parts from the same manufacturer are necessary for new designs and ongoing production requirements.

Substiute Parts

AT45DB321D-MU-SL954

Renesas Electronics CorporationIn Stock: 1090AT45DB321D-MU-SL954 Datasheet

Current PartRFQ

AT45DB321E-MHF2B-T

Renesas Electronics CorporationIn Stock: 811AT45DB321E-MHF2B-T Datasheet

DirectRFQ

AT45DB321E-MWHF2B-T

Renesas Electronics CorporationIn Stock: 2538AT45DB321E-MWHF2B-T Datasheet

MFR RecommendedRFQ

AT45DQ321-MWHF2B-T

Renesas Electronics CorporationIn Stock: 1230AT45DQ321-MWHF2B-T Datasheet

MFR RecommendedRFQ

AT45DQ321-MWHFHJ-T

Renesas Electronics CorporationIn Stock: 747AT45DQ321-MWHFHJ-T Datasheet

MFR RecommendedRFQ

AT45DQ321-MWHFHK-T

Renesas Electronics CorporationIn Stock: 765AT45DQ321-MWHFHK-T Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT45DB321D-MU-SL954 is determined by the following critical parameters:

• Memory Capacity: All substitutes maintain 32Mbit capacity with identical 512 Bytes x 8192 pages organization
• Memory Interface: SPI interface is preserved across all substitute parts
• Operating Temperature Range: All substitutes support -40°C to 85°C operation
• Supply Voltage Compatibility: Substitute parts operate at 2.3V ~ 3.6V, which encompasses the original 2.7V ~ 3.6V range
• Package Form Factor: Substitutes are available in 8-VDFN and 8-UDFN packages with exposed pad
• Mounting Technology: All parts are surface mount compatible

The substitute parts are grouped into two categories based on clock frequency capability: 85 MHz variants (AT45DB321E series) and 104 MHz variants (AT45DQ321 series). All substitute parts transition from obsolete to active product status with improved compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

For Direct Package Compatibility (8-VDFN 6x5 to 8-VDFN 6x8): AT45DB321E-MWHF2B-T is the primary substitute when package footprint compatibility is required. This part maintains the 8-VDFN package family while providing improved performance at 85 MHz, active product status, ROHS3 compliance, and reduced moisture sensitivity (MSL 1 vs. MSL 3).

For Enhanced Performance (104 MHz Operation): AT45DQ321-MWHF2B-T, AT45DQ321-MWHFHJ-T, and AT45DQ321-MWHFHK-T offer the highest clock frequency at 104 MHz with identical compliance certifications and moisture sensitivity ratings. These parts are suitable for applications requiring higher data throughput.

For Alternative Package Form Factor (8-UDFN): AT45DB321E-MHF2B-T provides an 8-UDFN (5x6) package option at 85 MHz operation. This variant is applicable when board layout constraints permit the smaller UDFN footprint.

All substitute parts feature active product status, ROHS3 compliance, REACH unaffected status, and improved moisture sensitivity levels compared to the obsolete original part, supporting long-term supply chain reliability and regulatory compliance.

Frequently Asked Questions (FAQ)

Q: Can AT45DB321E and AT45DQ321 series parts be used interchangeably with the AT45DB321D-MU-SL954?

A: Yes, within the constraints of package form factor and clock frequency requirements. All parts share identical 32Mbit capacity, SPI interface, memory organization, and operating temperature range. The AT45DB321E series operates at 85 MHz while AT45DQ321 series operates at 104 MHz, both exceeding the original 66 MHz specification. Supply voltage compatibility is maintained across all variants.

Q: What are the package differences between substitute parts?

A: AT45DB321E-MHF2B-T uses 8-UDFN (5x6) packaging, while AT45DB321E-MWHF2B-T and all AT45DQ321 variants use 8-VDFN (6x8) packaging. The original AT45DB321D-MU-SL954 uses 8-VDFN (6x5). Physical footprint differences require PCB layout verification before substitution.

Q: Are there compliance differences between the original and substitute parts?

A: The original AT45DB321D-MU-SL954 does not specify RoHS or REACH status. All substitute parts are ROHS3 compliant and REACH unaffected. Moisture sensitivity improves from MSL 3 (168 hours) to MSL 1 (unlimited) across all substitutes.

Q: What is the impact of higher clock frequency on system design?

A: The 85 MHz and 104 MHz variants support faster data transfer rates than the original 66 MHz part. Systems designed for 66 MHz operation are backward compatible with higher frequency parts. No design changes are required unless the system is specifically optimized for the original frequency.

Q: How does write cycle time differ between parts?

A: The original part specifies 6ms page write cycle time. All substitute parts reduce this to 4ms, providing improved write performance. This enhancement does not affect compatibility with existing firmware or software implementations.