Skyworks Solutions Inc. SI3460-EVB

Overview

SI3460-EVB from Silicon Laboratories is an IEEE 802.3af-compliant single-port Power Sourcing Equipment (PSE) evaluation board built around the Si3460 PSE controller IC. It delivers –48 V output from a 12–15 V isolated input, supports full detection/classification/disconnect sequences, and implements SELV-compliant negative-polarity power injection for midspan or endpoint PoE applications.

For engineers reviewing the SI3460-EVB datasheet, SI3460-EVB pinout, SI3460-EVB application, or SI3460-EVB equivalent, this board enables rapid validation of PoE PSE functionality-including IEEE-compliant signature detection (23.75–26.25 kΩ), classification (Class 0–4), –50 V output regulation, short-circuit protection (<75 ms disconnect), and robust disconnect timing (300–400 ms open-circuit detection).

Technical Context

The SI3460-EVB implements a complete single-port PSE reference design using the Si3460 controller, which integrates digital PWM-based DC-DC conversion to generate –48 V output. It performs all IEEE 802.3af physical layer functions: detection (2.8 V / 10 V probing), classification (15.5–20.5 V, 8–45 mA), power-up (44–57 V), and disconnect (5 mA threshold, 300–400 ms hold time).

Operating mode (endpoint/midspan, Class support, auto-restart behavior) is configured via STATUS pin voltage (0.25–3.0 V) set by resistor divider R28/R30. The board includes surge protection (SMAJ58A), thermal-aware layout (shielded 150 µH inductor L1), and EMI-optimized switching (250 kHz PWM, shielded magnetics, low-ESR output caps).

Key Specifications

Availability

SI3460-EVB is available at Aetrix Electronics and suitable for Power-over-Ethernet development, IEEE 802.3af compliance testing, and PSE controller validation requiring stable component supply and documented reference design fidelity.

Supply support for SI3460-EVB 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

Silicon Laboratories is a fabless semiconductor company specializing in mixed-signal ICs for timing, connectivity, and power management, with deep expertise in energy-efficient embedded systems and interoperable interface solutions.

The SI3460-EVB belongs to Silicon Labs' Power-over-Ethernet product line, designed specifically to accelerate development of standards-compliant, single-port PSE hardware for telecom infrastructure, IP surveillance, and VoIP endpoint equipment.

FAQ

What is the primary function of the SI3460-EVB?

The SI3460-EVB is a fully assembled, tested evaluation board for the Si3460 IEEE 802.3af Power Sourcing Equipment controller. It implements a complete single-port PSE solution-including detection, classification, –48 V power delivery, and disconnect-with validated schematics, PCB layout, and BOM. Engineers use the SI3460-EVB to verify PoE system behavior before custom design integration.

Does the SI3460-EVB support both endpoint and midspan PoE configurations?

Yes, the SI3460-EVB supports both endpoint and midspan modes via STATUS pin programming (R28/R30 resistor divider). In midspan mode, it operates on 10/100BASE-T spare pairs as shown in Figure 1; in endpoint mode, it supports 10/100/1000BASE-T with power on data or spare pairs. Mode selection directly affects backoff timing and restart behavior per IEEE 802.3af requirements.

What are the key safety and compliance features implemented on the SI3460-EVB?

The SI3460-EVB implements SELV-compliant –48 V output (<57 Vdc under all conditions), input isolation (no GND connection to pin #11), surge protection (SMAJ58A clamp diode per IEEE 802.3 intra-building lightning spec), and robust fault handling-including UVLO (10 V threshold), short-circuit disconnect (<75 ms), and overload current limiting (400 mA/60 ms timeout). It has passed UNH IoL IEEE 802.3 Clause 33 interoperability testing.

Is the SI3460-EVB recommended for new designs?

No - the SI3460-EVB is explicitly marked "Not Recommended for New Designs" in its official documentation (Rev. 1.2, March 2013). Silicon Labs recommends the Si3462 and its associated evaluation platform for new PoE PSE development due to enhanced feature set, improved efficiency, and extended lifecycle support. The SI3460-EVB remains valid for legacy validation and educational use.

How does the SI3460-EVB indicate operational status and faults?

The SI3460-EVB uses a single STATUS LED with three distinct behaviors: blinking at ~3 Hz during detection, steady ON after successful power-up, and rapid flashing (10 Hz) for faults-including classification mismatch, overcurrent (>400 mA sustained), UVLO (<10 V input), or short circuit. Flashing patterns are defined in Section 5.10 and provide immediate visual feedback without external instrumentation.