Skyworks Solutions Inc. SI34061FB5VC4KIT

Overview

SI34061FB5VC4KIT from Skyworks Solutions is an isolated, Class 4 (30 W), EMI-compliant evaluation board for the Si34061 IEEE 802.3at PoE+ Powered Device controller. It implements a flyback topology with synchronous rectification, delivers 5 V / 6 A output, and supports dual-input power sourcing (PoE PSE or wall adapter) with wall-adapter priority.

For engineers reviewing the SI34061FB5VC4KIT datasheet, SI34061FB5VC4KIT pinout, SI34061FB5VC4KIT application, or SI34061FB5VC4KIT equivalent, this board serves as a production-ready reference design for PoE-powered edge devices requiring robust EN55032 Class B compliance, thermal stability at full load, and seamless PSE-to-wall-adapter switchover without output interruption.

Technical Context

The SI34061FB5VC4KIT implements a peak-current-mode controlled isolated flyback converter using the Si34061 IC, which integrates both the IEEE 802.3at PD interface and dc-dc controller. It operates at a fixed 200 kHz switching frequency set by R14 (95.3 kΩ) and employs adaptive soft-start, MPS generation, and pulse-skipping light-load management.

Input power routing prioritizes the wall adapter (J3, 33–57 V) over PoE (J1, 37–57 V), with automatic ASUP-pin detection enabling zero-interruption transition. Protection includes integrated transient overvoltage handling (IEC 61000-4-5 up to 4.4 kV), output short-circuit response, and thermal shutdown.

Key Specifications

Availability

SI34061FB5VC4KIT is available at Aetrix Electronics and suitable for Power over Ethernet (PoE+) system validation, industrial IoT gateway development, and VoIP phone reference design requiring stable component supply, pre-validated EMI performance, and dual-input redundancy.

Supply support for SI34061FB5VC4KIT includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Skyworks Solutions is a global semiconductor company specializing in analog and mixed-signal connectivity solutions for wireless, broadband, automotive, and industrial applications.

The Si34061 product line is designed specifically for high-efficiency, isolated PoE+ Powered Device applications-enabling compact, standards-compliant, and thermally robust power conversion in space-constrained edge devices.

FAQ

What is the primary function of the SI34061FB5VC4KIT evaluation board?

The SI34061FB5VC4KIT is an isolated, Class 4 (30 W), EMI-compliant reference design board for the Si34061 PoE+ PD controller. It demonstrates a complete flyback-based power supply capable of delivering 5 V / 6 A from either an IEEE 802.3at-compliant PSE or a wall adapter-with automatic priority-based switchover. The SI34061FB5VC4KIT validates real-world performance including EN55032 Class B compliance, thermal behavior at full load, and protection features like MPS, soft-start, and short-circuit response.

Does the SI34061FB5VC4KIT support both mid-span and end-span PoE power injection?

Yes, the SI34061FB5VC4KIT supports both mid-span and end-span PoE configurations via its RJ45 connector (J1). It accepts power across either the spare pairs (blue/white-blue and brown/white-brown) for end-span or the data pairs (green/white-green and orange/white-orange) for mid-span, per IEEE 802.3at specifications. The board's input interface includes integrated surge protection and maintains full Class 4 functionality regardless of injection method.

How does the SI34061FB5VC4KIT handle power source priority between PoE and wall adapter?

The SI34061FB5VC4KIT uses the ASUP pin to detect wall adapter presence at connector J3 (33–57 V range) and automatically switches to wall-adapter power with zero output interruption. When the wall adapter is connected, the Si34061 disables PoE detection signatures, preventing PSE engagement. This priority logic ensures continuous operation during PSE outages or maintenance-making the SI34061FB5VC4KIT ideal for mission-critical PoE-powered infrastructure where uptime is essential.

What EMI standards does the SI34061FB5VC4KIT meet, and how was compliance verified?

The SI34061FB5VC4KIT passes EN55032 Class B for both radiated and conducted emissions using average and peak detectors. Radiated testing was performed at 3 m distance with vertical/horizontal polarization and quasi-peak validation at critical frequencies; conducted testing used LISN-based measurement per CISPR 32. All test results-documented in UG333-are measured at full 30 W load (5 V / 6 A) and 50 V input, confirming robust EMI performance without external filtering components.

Can the SI34061FB5VC4KIT be used to evaluate thermal performance under sustained load?

Yes, the SI34061FB5VC4KIT includes comprehensive thermal characterization in UG333, with infrared images showing top- and bottom-side temperatures at full 30 W load (ambient 26 °C). Measured hot-spot temperatures remain within safe operating limits for extended operation, validating the board's copper pour layout, transformer selection, and synchronous rectifier implementation. This data directly supports thermal modeling for derivative designs using the Si34061 IC.