Skyworks Solutions Inc. SI3404BKC2-KIT

Overview

SI3404BKC2-KIT from Skyworks Solutions is an evaluation kit for the Si3404 IEEE 802.3at Type 1-compliant Power-over-Ethernet (PoE) powered device (PD) controller IC. It integrates a hotswap switch, current-mode DC-DC converter, surge suppression, and classification/detection circuitry in a 4 × 4 mm QFN-20 package, supporting isolated/non-isolated flyback and buck topologies with tunable switching frequency (100–500 kHz). The kit enables rapid validation of PoE PD designs for IP phones, wireless access points, and surveillance cameras.

For engineers reviewing the SI3404BKC2-KIT datasheet, SI3404BKC2-KIT pinout, SI3404BKC2-KIT application, or SI3404BKC2-KIT equivalent, this kit provides reference schematics, BOM, layout files, and test reports for Si3404-based PoE PD implementations - including non-isolated flyback, isolated flyback, and buck configurations - with full support for IEEE 802.3at Type 1 detection, classification, and thermal/overcurrent protection.

Technical Context

The SI3404BKC2-KIT implements the complete Si3404 IC interface: its board hosts the 20-pin QFN-20 Si3404-A-GM IC, external RDET/RCLASS resistors for IEEE 802.3af/at signature generation, RFREQ tuning resistor for oscillator frequency selection (250 kHz default or 100–500 kHz), and discrete components for flyback/buck operation including SWO driver, FBL/FBH feedback paths, ISNS current sense, and VT15 auxiliary bias winding support. It validates all three supported topologies using the same core IC.

Key functional blocks include the integrated 120 V-rated hotswap switch (HSSW) with inrush control and overload recovery (TWAITHSSW = 96 ms), current-mode PWM controller with <1 Ω internal FET (RONDCDC = 0.9 Ω typ), and dual-regulator system (5 V VDD output, 11 V internal rail). The kit demonstrates EROUT-based loop compensation, transformer bias winding integration via VT15, and output short protection triggered by >1 ms high EROUT signal.

Key Specifications

Availability

SI3404BKC2-KIT is available at Aetrix Electronics and suitable for PoE-powered voice over IP telephones, wireless access points, and security IP cameras requiring stable component supply and validated reference design support.

Supply support for SI3404BKC2-KIT 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, automotive, and industrial applications.

The Si3404 product line delivers fully integrated PoE PD interfaces targeting compact, high-efficiency Ethernet-powered devices - designed specifically for cost-sensitive, space-constrained applications requiring IEEE 802.3at Type 1 compliance without external FETs or complex support circuitry.

FAQ

What is the primary purpose of the SI3404BKC2-KIT?

The SI3404BKC2-KIT is an evaluation kit for the Si3404 PoE PD controller IC. It provides a fully assembled, tested PCB with reference schematics, layout files, and documentation to accelerate development of IEEE 802.3at Type 1-compliant powered devices. Engineers use the SI3404BKC2-KIT to validate flyback and buck topologies, verify detection/classification signatures, and characterize thermal and transient performance before final design release.

Does the SI3404BKC2-KIT support both isolated and non-isolated power topologies?

Yes, the SI3404BKC2-KIT supports isolated flyback (using EROUT current-mode feedback), non-isolated flyback (using FBL referenced to VSS), and buck (using FBH referenced to VPOS) topologies. Each configuration is implemented on the same board with selectable jumpers and component placements, enabling direct comparison of efficiency, footprint, and EMI behavior across architectures using the same SI3404BKC2-KIT hardware.

How does the SI3404BKC2-KIT implement IEEE 802.3at Type 1 compliance?

The SI3404BKC2-KIT implements IEEE 802.3at Type 1 compliance through the onboard Si3404-A-GM IC, which integrates detection (25 kΩ signature between RDET and VPOS), classification (programmable current via RCL), and hotswap control. External RDET (24.9 kΩ) and RCLASS (48.7 Ω for Class 3) resistors are pre-installed per specification, and the SI3404BKC2-KIT's firmware-free operation ensures deterministic timing for VDET (1.5–10.1 V), VCLASS (≤14.5 V), and reset thresholds.

Can the SI3404BKC2-KIT be used to evaluate auxiliary bias winding integration?

Yes, the SI3404BKC2-KIT includes VT15 pin routing and test points to connect an external 12.5–16.5 V auxiliary bias winding from the transformer primary side. This allows engineers to measure efficiency gains versus internal regulation, validate voltage tolerance (VMV_VT15 = 14.5 V typ), and confirm proper startup sequencing - all using the same SI3404BKC2-KIT board without modification.

What protection features are validated by the SI3404BKC2-KIT?

The SI3404BKC2-KIT validates integrated protection features of the Si3404 IC, including hotswap inrush limiting (170 mA typ), overload recovery (TWAITHSSW = 96 ms), output short detection (THICCUP = 1 ms), average current sensing (VISNS_OVC = –270 mV), and thermal shutdown (Tshd = 160 °C). These are confirmed via oscilloscope waveforms, thermal imaging, and fault injection tests documented in the SI3404BKC2-KIT User Guide.