STMicroelectronics STEVAL-TSP004V2

Overview

STEVAL-TSP004V2 from STMicroelectronics is a IEEE 802.3at-compliant Power over Ethernet (PoE+) reference design implementing an isolated synchronous flyback converter delivering 5 VDC ±5% at up to 4 A. It integrates the PM8803 PoE PD interface with PWM controller and supports dual-input operation (PoE or auxiliary DC sources). Used in IP surveillance cameras, VoIP phones, and wireless access points requiring high-efficiency, compact PoE-powered 5 V rails.

For engineers reviewing the STEVAL-TSP004V2 datasheet, STEVAL-TSP004V2 schematic, STEVAL-TSP004V2 application, or STEVAL-TSP004V2 equivalent, this page provides verified topology details, efficiency curves, input/output specifications, auxiliary source configuration options, and design flexibility for PoE+ system integration.

Technical Context

The STEVAL-TSP004V2 implements a continuous conduction mode (CCM) isolated flyback converter with synchronous rectification driven by transformer-coupled gate signals. It uses the PM8803 IC - which embeds IEEE 802.3at-compliant classification, detection, and power management alongside a current-mode PWM controller.

Support for auxiliary inputs includes two dedicated connectors: AUX I accepts wall adapters below the PoE UVLO threshold while retaining inrush/DC current limiting, and AUX II enables priority switchover to local supply. Configurable options include active or passive diode bridges, 4-pair PSE detection, optional booster circuit, and primary-side snubber variants (including active clamp).

Key Specifications

Availability

STEVAL-TSP004V2 is available at Aetrix Electronics and suitable for IP surveillance systems, VoIP endpoint designs, and enterprise Wi-Fi access point development requiring stable component supply, rapid prototyping support, and production-ready PoE+ reference implementation.

Supply support for STEVAL-TSP004V2 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, sensors, and analog products for industrial, automotive, and consumer applications.

The STEVAL-TSP004V2 belongs to ST's Power Supply Evaluation Board product line, developed to accelerate adoption of IEEE 802.3at-compliant PoE+ infrastructure by providing fully validated, schematically documented, and test-characterized reference designs.

FAQ

Does STEVAL-TSP004V2 support IEEE 802.3bt (PoE++)?

No. STEVAL-TSP004V2 is designed specifically for IEEE 802.3at (PoE+), supporting up to 25.5 W delivered power. It does not implement the four-pair power negotiation, higher classification, or extended signature detection required for 802.3bt Type 3/4 compliance.

Can STEVAL-TSP004V2 operate solely from an auxiliary DC source?

Yes. The board supports standalone operation from either AUX I (wall adapter input, <57 V) or AUX II (priority auxiliary input). AUX II overrides PoE when both sources are present, enabling seamless failover in hybrid power architectures.

What is the role of the PM8803 on this board?

The PM8803 serves as the core controller: it performs IEEE 802.3at-compliant detection/classification, manages inrush current, regulates the flyback PWM stage, monitors fault conditions, and enables auxiliary source arbitration - all within a single HTSSOP20 package.

Is synchronous rectification implemented with external MOSFETs or integrated drivers?

Synchronous rectification is implemented using discrete N-channel MOSFETs (e.g., STL66N3LLH5) driven by a gate-drive transformer - not integrated drivers. This architecture allows layout optimization and thermal separation while maintaining high efficiency at full load.