DS21FF42 Equivalent & Substitute Parts

Part Overview

The DS21FF42 is a telecom interface IC manufactured by Analog Devices Inc./Maxim Integrated, designed for telecommunications applications requiring parallel/serial interface functionality. This component is packaged in a 300-PBGA (27x27) configuration and operates within a supply voltage range of 2.97V to 3.63V with a maximum supply current of 300mA.

The DS21FF42 has reached obsolete product status, making it necessary to identify functionally equivalent substitute components for ongoing system maintenance, redesign, or new production requirements. The obsolescence of this part necessitates evaluation of active alternative solutions that maintain compatibility with existing system requirements.

Substiute Parts

DS21FF42

Analog Devices Inc./Maxim IntegratedIn Stock: 2184DS21FF42 Datasheet

Current PartRFQ

DS26518GN+

Analog Devices Inc./Maxim IntegratedIn Stock: 2247DS26518GN+ Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DS21FF42 is based on the following critical parameters:

• Manufacturer Alignment: Both the main part and substitute are sourced from Analog Devices Inc./Maxim Integrated, ensuring design continuity and technical support consistency.
• Functional Category: Both components operate within the Interface category, maintaining functional equivalence for telecom applications.
• Interface Protocol: The substitute maintains parallel/serial interface capability required for system integration.
• Surface Mount Technology: Both components utilize surface mount packaging, compatible with existing PCB assembly processes.
• Supply Voltage Compatibility: Operating voltage ranges must support system power delivery requirements.
• Thermal Operating Range: Temperature specifications must accommodate the intended application environment.

The DS26518GN+ is identified as the manufacturer-recommended substitute, representing an active product with enhanced compliance characteristics and extended operational temperature range.

Parameter Comparison

Engineering Selection Recommendations

The DS26518GN+ is the manufacturer-recommended substitute for the obsolete DS21FF42. Selection of this substitute is supported by the following factors:

• Active Product Status: The DS26518GN+ maintains active production status, ensuring long-term availability and technical support from Analog Devices Inc./Maxim Integrated.
• Enhanced Compliance: The substitute achieves ROHS3 compliance, addressing regulatory requirements that may not be met by the non-compliant original part.
• Extended Temperature Range: Operating temperature specification of -40°C to 85°C provides broader environmental compatibility compared to the original 0°C to 70°C range.
• Improved Moisture Handling: MSL 3 rating with 168-hour tolerance offers superior moisture resistance compared to MSL 4 with 72-hour tolerance.
• Same Manufacturer Source: Continuity with Analog Devices Inc./Maxim Integrated ensures consistent design philosophy and technical documentation.

Component selection must account for package geometry differences (300-PBGA versus 256-CSBGA) and PCB layout modifications that may be required during integration.

Frequently Asked Questions (FAQ)

Q: Why is the DS21FF42 being discontinued? A: The DS21FF42 has reached obsolete status in the manufacturer's product lifecycle. Obsolescence typically occurs when a product no longer meets current market demand or regulatory requirements. The DS26518GN+ represents the active alternative for new designs and ongoing production.

Q: Are the package sizes interchangeable? A: No. The DS21FF42 uses a 300-PBGA (27x27) package, while the DS26518GN+ uses a 256-CSBGA (17x17) package. These are different physical footprints requiring PCB redesign and re-layout. The smaller package of the substitute may reduce board space requirements.

Q: What are the voltage supply differences? A: The DS21FF42 operates at 2.97V to 3.63V, while the DS26518GN+ operates at 3.135V to 3.465V. The substitute has a narrower voltage window. System power delivery must be verified to ensure compatibility with the substitute's tighter voltage specification.

Q: Does the substitute support the same interface protocols? A: The DS21FF42 provides parallel/serial interface capability. The DS26518GN+ is specified as a transceiver supporting T1/E1/J1 protocols. Protocol compatibility must be verified against specific system requirements before substitution.

Q: What is the significance of RoHS compliance differences? A: The DS21FF42 is RoHS non-compliant, while the DS26518GN+ is ROHS3 compliant. For applications subject to RoHS regulations or customer requirements, the substitute provides regulatory alignment. Existing inventory of the original part may not meet current procurement standards.

Q: How do moisture sensitivity levels affect handling? A: The DS21FF42 has MSL 4 with 72-hour floor life, requiring more frequent baking cycles and careful moisture control. The DS26518GN+ has MSL 3 with 168-hour floor life, providing greater handling flexibility and reduced moisture management complexity during assembly.

Q: Can I use the DS26518GN+ as a direct replacement without design changes? A: No. The different package geometry requires PCB layout modifications. Additionally, the narrower voltage specification and different interface protocol require system-level verification before implementation.