SI3459-B04-IM Power Over Ethernet Controller Equivalent & Substitute Parts

Part Overview

The SI3459-B04-IM is an 8-channel Power Over Ethernet (PoE) controller manufactured by Skyworks Solutions Inc., designed for 802.3at standard compliance. This device functions as a PSE (Power Sourcing Equipment) controller and is packaged in a 56-QFN (8x8) surface mount configuration.

The SI3459-B04-IM carries a "Not For New Designs" product status, indicating that Skyworks Solutions Inc. has discontinued active development and support for this model. Organizations requiring equivalent functionality for new designs or replacement applications must evaluate suitable substitute components that maintain electrical and mechanical compatibility while offering active product support.

Substiute Parts

SI3459-B04-IM

Skyworks Solutions Inc.In Stock: 722SI3459-B04-IM Datasheet

Current PartRFQ

SI3473A-A01-IM

Skyworks Solutions Inc.In Stock: 930SI3473A-A01-IM Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SI3459-B04-IM is determined by the following critical parameters:

Mechanical Compatibility:

• Package type: 56-VFQFN Exposed Pad (56-QFN 8x8)
• Mounting type: Surface Mount
• Moisture Sensitivity Level: 3 (168 Hours)

Functional Compatibility:

• Device type: PSE Controller
• Channel count: 8 channels
• Operating temperature range: -40°C ~ 85°C (TA)

Electrical Compatibility:

• PoE standard support: Must support 802.3at or higher standards (802.3at, 802.3at+, 802.3bt)
• Supply voltage range: Acceptable if overlapping or compatible with system design
• RoHS compliance: ROHS3 Compliant

The SI3473A-A01-IM qualifies as a substitute based on matching package specifications, identical channel count, compatible operating temperature range, and support for 802.3at standard alongside additional 802.3af and 802.3bt capabilities. The substitute maintains identical mechanical form factor and environmental compliance ratings.

Parameter Comparison

Engineering Selection Recommendations

For New Designs: The SI3473A-A01-IM is the appropriate selection. This component carries an "Active" product status, ensuring ongoing manufacturer support, availability, and compliance updates. The identical package form factor (56-VFQFN Exposed Pad) and channel configuration (8 channels) enable direct mechanical integration into existing PCB layouts designed for the SI3459-B04-IM.

For Replacement Applications: The SI3473A-A01-IM provides functional equivalence with enhanced capability. Both components maintain identical operating temperature ranges (-40°C ~ 85°C) and moisture sensitivity specifications (MSL 3, 168 Hours), ensuring compatibility with existing environmental and storage requirements. Both components are ROHS3 Compliant.

Supply Voltage Consideration: The SI3459-B04-IM operates at 44V ~ 57V supply voltage, while the SI3473A-A01-IM operates at 3V ~ 3.6V supply voltage. These represent fundamentally different power supply architectures. System integration requires verification that the substitute component's supply voltage range aligns with available power distribution infrastructure.

Standards Expansion: The SI3473A-A01-IM supports 802.3at (PoE+), 802.3af (PoE), and 802.3bt standards, compared to the SI3459-B04-IM's 802.3at support. This expanded standard support provides additional flexibility for multi-standard PoE deployments without requiring component substitution.

Frequently Asked Questions (FAQ)

Q: Can the SI3473A-A01-IM be used as a direct replacement for the SI3459-B04-IM in existing designs?

A: Mechanical and thermal compatibility is confirmed. Both components use identical 56-VFQFN Exposed Pad packaging and operate within the same temperature range (-40°C ~ 85°C). However, the supply voltage specifications differ significantly (44V ~ 57V versus 3V ~ 3.6V). Direct replacement requires verification that the system power supply can accommodate the SI3473A-A01-IM's voltage requirements.

Q: What is the significance of the "Not For New Designs" status on the SI3459-B04-IM?

A: This designation indicates that Skyworks Solutions Inc. has concluded active development and support for this component. New product designs should utilize the SI3473A-A01-IM, which carries "Active" status and receives ongoing manufacturer support, ensuring access to technical documentation, design resources, and long-term availability.

Q: Are both components compatible with the same PCB footprint?

A: Yes. Both the SI3459-B04-IM and SI3473A-A01-IM use the 56-VFQFN Exposed Pad package with identical physical dimensions. PCB layouts designed for either component are mechanically interchangeable.

Q: What are the differences in PoE standard support between these components?

A: The SI3459-B04-IM supports 802.3at (PoE) standard. The SI3473A-A01-IM supports 802.3at (PoE+), 802.3af (PoE), and 802.3bt standards. The SI3473A-A01-IM's expanded standard support enables compatibility with a broader range of powered devices without requiring additional controller components.

Q: Do both components meet the same environmental compliance requirements?

A: Yes. Both components are ROHS3 Compliant and carry identical Moisture Sensitivity Level ratings (MSL 3, 168 Hours). Environmental handling, storage, and compliance requirements are equivalent.

Q: What is the inventory status for these components?

A: The SI3459-B04-IM has 628 pieces in stock (Tube packaging). The SI3473A-A01-IM has 912 pieces in stock (Tray packaging). Availability should be verified with the component supplier for current project requirements.