STMicroelectronics STEVAL-POE002V1

Overview

STEVAL-POE002V1 from STMicroelectronics is a two-stage IEEE 802.3bt-compliant Powered Device (PD) reference design delivering 5 VDC ±2.5% at up to 8 A (40 W) from 4-pair PoE or auxiliary DC input (40–60 VDC). It integrates the PM8805 PoE interface with dual-active bridge rectification and the PM8804 peak-current-mode PWM controller managing a synchronous flyback DC-DC stage.

For engineers reviewing the STEVAL-POE002V1 datasheet, STEVAL-POE002V1 pinout, STEVAL-POE002V1 application, or STEVAL-POE002V1 equivalent, this reference design supports rapid validation of high-efficiency PoE-PD power architectures for retail point-of-sale terminals, industrial IoT gateways, and networked surveillance endpoints requiring stable 5 V/8 A output under dynamic load steps.

Technical Context

The first stage implements full active bridge rectification using the PM8805, supporting IEEE 802.3bt Class 5 (up to 71.3 W input), backward compatibility with 802.3af/at, and detection/classification via 25 kΩ signature resistor and 75 kΩ classification current sensing. Input surge protection includes bidirectional TVS diodes (SM15T68CA) and gas discharge tubes (B88069X9231T203).

The second stage employs a fixed-frequency (≈280 kHz) synchronous flyback topology with secondary-side synchronous rectification driven by a gate driver transformer. The PM8804 provides programmable soft-start (10 ms), blanking time (70 ns), and feedback regulation via TL431-based optocoupled loop with 47 nF compensation capacitor and 91 kΩ divider for precise 5 V output stability.

Key Specifications

Availability

STEVAL-POE002V1 is available at Aetrix Electronics and suitable for retail point-of-sale systems, industrial IoT gateways, IP camera power supplies, and networked digital signage requiring stable component supply and fast PoE-PD design validation.

Supply support for STEVAL-POE002V1 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, designing and manufacturing microcontrollers, analog ICs, power management devices, and sensors for industrial, automotive, and consumer applications.

This reference design belongs to ST's Power over Ethernet (PoE) evaluation platform family, engineered to accelerate development of IEEE 802.3bt-compliant PD systems with integrated active bridge and high-efficiency DC-DC conversion.

FAQ

What input power standards does STEVAL-POE002V1 support?

STEVAL-POE002V1 fully complies with IEEE 802.3bt (Type 3/4, 4-pair), and maintains backward compatibility with 802.3af (Type 1) and 802.3at (Type 2) PSEs. It accepts 40–60 VDC from PoE or local auxiliary sources, with integrated signature resistor (25 kΩ) and classification circuitry (75 kΩ) meeting all three standards' detection requirements.

How is output voltage accuracy maintained under varying loads?

Output voltage is regulated to 5 V ±2.5% using a TL431-based optocoupled feedback loop with precision resistive divider (91 kΩ/6.8 kΩ) and 47 nF compensation capacitor. The PM8804's current-mode control and 280 kHz switching frequency ensure tight transient response, limiting ΔV to ≈700 mV during 100%→50% load steps.

Does STEVAL-POE002V1 include surge and ESD protection?

Yes - it features dual-stage protection: primary-side bidirectional TVS diodes (SM15T68CA, 68 V clamp) on Ethernet lines and gas discharge tube (B88069X9231T203) for common-mode surge suppression. Secondary-side 100 V-rated capacitors (C29, C20) and ferrite beads (L5, L6) further suppress differential-mode noise and transients.

Can STEVAL-POE002V1 operate without PoE input?

Yes - it supports auxiliary DC input (40–60 VDC) via J9/J10 terminals, bypassing the PM8805 Ethernet interface stage. The PM8804 DC-DC controller remains fully functional, enabling standalone 5 V/8 A operation for lab testing or hybrid power architectures where PoE is unavailable or supplemental.