High efficiency integrated IEEE 802.3at PoE-PD interface and PWM controller type 2 PSE indicator, plus support for forward active clamp topology

The PM8803 integrates a Power over Ethernet (PoE) interface and a current mode PWM controller to simplify the design of the power supply sections of all powered devices. The PoE/PoE+ interface includes all functions required by the IEEE 802.3at as well as detection, classification, undervoltage lockout (UVLO) and inrush current limitation.

The PM8803 specifically performs IEEE802.3at Layer 1 hardware classification, providing the system with an indication of Type 2 PSE successful detection.

The PM8803 has been designed to work with power either from the Ethernet cable or from an external power source such as a wall adapter, ensuring the priority of the auxiliary source over the PoE. The DC-DC section of the PM8803 features a programmable oscillator frequency, an adjustable slope compensation, dual complementary low-side drivers, programmable dead time and an internal temperature sensor.

The PM8803 targets high-efficiency conversion under all load conditions supporting flyback, forward, forward with active clamp converters and synchronous rectification.

Key Features

  • IEEE 802.3at compliant PD interface
  • Works with power supplied from Ethernet LAN cables or from local auxiliary sources
  • Successful IEEE802.3at Layer1 classification indicator
  • Integrated 100 V, 0.45 Ω, 1 A hot-swap MOSFET
  • Accurate 140 mA typ. inrush current level
  • Programmable classification current
  • Programmable DC current limit up to 1 A
  • Integrated high voltage start-up bias regulator
  • Thermal shutdown protection
  • Current mode pulse width modulator
  • Programmable oscillator frequency
  • 80% maximum duty cycle with internal slope compensation
  • Support for flyback, forward, forward active clamp, flyback with synchronous rectification


Technical Documentation

Product Specifications
Description Version Size
DS7139 DS7139: High-efficiency, IEEE 802.3at compliant integrated PoE-PD interface and PWM controller 3.0 1 MB
Application Notes
Description Version Size
AN4006 AN4006: Designing a high-efficiency (60 W on 4 pairs) PoE converter using the PM8803 and an external current booster 1.0 3 MB
AN3373 AN3373: IEEE802.3at compliant PD + PS design based on PM8803 low power, synchronous flyback PoE converter 1.0 1 MB
AN3387 AN3387: PM8803 layout guidelines 1.0 944 KB
AN4473 AN4473: PoE synchronous flyback, IEEE802.3at compliant, 5V - 4A PD converter based on the PM8803 controller 1.1 2 MB
User Manuals
Description Version Size
UM1063 UM1063: EVALPM8803-FLY: IEEE802.3at compliant demonstration kit with synchronous flyback converter 2.0 1 MB
UM1062 UM1062: EVALPM8803-FWD: IEEE802.3at compliant demonstration kit with synchronous active clamp forward converter 1.1 1 MB

Publications and Collaterals

Description Version Size
PM8803: Integrated PoE+ PD interface and PWM controller 3.1 216 KB
Description Version Size
Brochure Power management guide 05.2016 4 MB

Tools and Software

Evaluation Tools
Solution Evaluation Tools

Sample & Buy

Part Number Package Packing Type Marketing Status Unit Price (US$) * Quantity ECCN (EU) ECCN (US) Country of Origin More info Order from ST Order from Distributors

(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office  or our Distributors

Quality & Reliability

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
PM8803TR ActiveHTSSOP20IndustrialEcopack2
PM8803 ActiveHTSSOP20IndustrialEcopack2

(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.