Equivalent & Substitute Parts for Renesas 621MILF Clock Buffer IC

Part Overview

The Renesas 621MILF is a Clock Fanout Buffer (Distribution) IC with a 1:4 input-to-output ratio, designed for 200 MHz clock distribution applications. This component features LVCMOS output and operates across a supply voltage range of 1.14V to 1.89V. The 621MILF is classified as obsolete, making identification of suitable substitute components essential for ongoing system support and new design implementations.

Substiute Parts

621MILF

Renesas Electronics CorporationIn Stock: 2090621MILF Datasheet

Current PartRFQ

621SDCGI

Renesas Electronics CorporationIn Stock: 1204621SDCGI Datasheet

MFR RecommendedRFQ

NB3N551DG

onsemiIn Stock: 1176NB3N551DG Datasheet

MFR RecommendedRFQ

NB3N551DR2G

onsemiIn Stock: 2324NB3N551DR2G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute components for the 621MILF are identified based on the following critical parameters that determine functional compatibility:

Primary Substitution Criteria:

• Package / Case: 8-SOIC (0.154", 3.90mm Width) — physical and electrical interface compatibility
• Ratio - Input:Output: 1:4 — functional distribution capability
• Number of Circuits: 1 — single buffer channel requirement
• Mounting Type: Surface Mount — assembly process compatibility
• RoHS Status: ROHS3 Compliant — regulatory compliance requirement

Secondary Compatibility Parameters:

• Frequency - Max: 200 MHz or higher
• Output Type: LVCMOS or compatible logic family
• Operating Temperature Range: Must encompass or exceed -40°C ~ 85°C

The substitute parts identified below meet these core criteria while offering active product status and improved supply availability.

Parameter Comparison

Engineering Selection Recommendations

621SDCGI (Renesas Electronics Corporation)

The 621SDCGI is the manufacturer-recommended direct substitute from Renesas. It maintains the same 1:4 fanout buffer architecture and 200 MHz maximum frequency as the 621MILF. The supply voltage range is broader (1.71V ~ 3.465V), and the operating temperature range extends to 105°C, providing enhanced thermal margin. Both components share identical package geometry (8-SOIC) and RoHS3 compliance. The 621SDCGI is classified as active product status with established supply channels. This part is the preferred choice for Renesas-based designs requiring direct functional equivalence.

NB3N551DG and NB3N551DR2G (onsemi)

Both onsemi variants (NB3N551DG in Tube packaging and NB3N551DR2G in Tape & Reel packaging) provide cross-manufacturer substitution. These parts maintain the 1:4 fanout buffer configuration and 8-SOIC package footprint. The maximum frequency specification is 180 MHz, which is lower than the 621MILF's 200 MHz rating. The supply voltage range (3V ~ 5.5V) is significantly higher than the original part. Both onsemi parts are active products with robust supply availability. Selection between NB3N551DG and NB3N551DR2G depends on procurement and assembly requirements: Tube packaging for lower-volume applications or Tape & Reel for automated assembly processes.

Selection Criteria Summary:

• For direct Renesas ecosystem compatibility: 621SDCGI
• For cross-manufacturer flexibility with higher supply voltage tolerance: NB3N551DG or NB3N551DR2G
• For automated assembly processes: NB3N551DR2G (Tape & Reel)
• For manual assembly or lower-volume builds: NB3N551DG (Tube)

All substitute parts maintain ROHS3 compliance and are classified as active products.

Frequently Asked Questions (FAQ)

Q: Can the 621SDCGI directly replace the 621MILF without circuit modifications?

A: The 621SDCGI maintains identical package geometry (8-SOIC), pinout configuration, and functional specifications (1:4 fanout, 200 MHz maximum frequency, LVCMOS output). The broader supply voltage range (1.71V ~ 3.465V) encompasses the original 621MILF range (1.14V ~ 1.89V). Direct substitution is supported at the component level. System-level validation is recommended for critical applications.

Q: What is the frequency difference between the 621MILF and the onsemi NB3N551 variants?

A: The 621MILF and 621SDCGI both specify 200 MHz maximum frequency. The onsemi NB3N551DG and NB3N551DR2G specify 180 MHz maximum frequency. For applications requiring operation at frequencies above 180 MHz, the 621SDCGI is the appropriate substitute. For applications operating at or below 180 MHz, the onsemi parts are functionally suitable.

Q: Are there supply voltage compatibility concerns when substituting with onsemi parts?

A: Yes. The 621MILF operates at 1.14V ~ 1.89V supply voltage, while the onsemi NB3N551 variants require 3V ~ 5.5V. Direct substitution in low-voltage applications (below 3V) is not supported. The 621SDCGI, with its 1.71V ~ 3.465V range, provides better compatibility with the original voltage specification while offering broader flexibility.

Q: What packaging options are available for the substitute parts?

A: The 621SDCGI is supplied in Tube packaging. The onsemi NB3N551DG is supplied in Tube packaging, while the NB3N551DR2G is supplied in Tape & Reel (TR) format. Tape & Reel packaging is optimized for high-volume automated assembly, while Tube packaging is suitable for manual assembly and lower-volume production.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. The 621SDCGI, NB3N551DG, and NB3N551DR2G are all ROHS3 compliant, matching the regulatory compliance status of the original 621MILF.

Q: Which substitute part offers the widest operating temperature range?

A: The 621SDCGI offers an operating temperature range of -40°C ~ 105°C, which exceeds the original 621MILF specification of -40°C ~ 85°C. The onsemi NB3N551 variants match the original temperature range at -40°C ~ 85°C.