PM8803 High-efficiency, IEEE 802.3at compliant integrated PoE-PD interface and PWM controller Datasheet - production data Applications VoIP phones, WLAN AP WiMAX CPEs Security cameras PoE/PoE+ powered device appliances Description The PM8803 integrates a Power over Ethernet (PoE) interface and a current mode PWM controller to simplify the design of the power Features supply sections of all powered devices. The IEEE 802.3at compliant PD interface PoE/PoE+ interface includes all functions Works with power supplied from Ethernet required by the IEEE 802.3at as well as LAN cables or from local auxiliary sources detection, classification, undervoltage lockout Successful IEEE802.3at Layer1 (UVLO) and inrush current limitation. classification indicator The PM8803 specifically performs IEEE802.3at Integrated 100 V, 0.45 , 1 A hot-swap Layer 1 hardware classification, providing the MOSFET system with an indication of Type 2 PSE Accurate 140 mA typ. inrush current level successful detection. Programmable classification current Programmable DC current limit up to 1 A The PM8803 has been designed to work with Integrated high voltage start-up bias power either from the Ethernet cable or from an external power source such as a wall adapter, regulator ensuring the priority of the auxiliary source over Thermal shutdown protection the PoE. The DC-DC section of the PM8803 Current mode pulse width modulator features a programmable oscillator frequency, an Programmable oscillator frequency adjustable slope compensation, dual 80% maximum duty cycle with internal slope complementary low-side drivers, programmable compensation dead time and an internal temperature sensor. Support for flyback, forward, forward active clamp, flyback with synchronous rectification The PM8803 targets high-efficiency conversion under all load conditions supporting flyback, forward, forward with active clamp converters and synchronous rectification. Table 1: Device summary Part number Package Packing PM8803 HTSSOP20 Tube PM8803TR HTSSOP20 Tape and reel May 2016 DocID018559 Rev 3 1/32 www.st.com This is information on a product in full production. Contents PM8803 Contents 1 Typical application circuits and block diagrams .......................... 5 1.1 Application circuits ............................................................................ 5 1.2 Block diagrams .................................................................................. 7 2 Pin descriptions and connection diagrams ................................... 9 3 Electrical specifications ................................................................ 11 3.1 Absolute maximum ratings .............................................................. 11 3.2 Thermal data ................................................................................... 11 3.3 Electrical characteristics .................................................................. 12 4 PD interface ................................................................................... 16 4.1 Detection ......................................................................................... 16 4.2 Classification ................................................................................... 16 4.3 Indication of successful 2-event classification ................................. 17 4.4 Undervoltage lockout ...................................................................... 19 4.5 Inrush and DC current limiting ......................................................... 19 4.6 High voltage start-up regulator ........................................................ 20 4.7 5 V bias regulator ............................................................................ 21 5 PWM controller .............................................................................. 22 5.1 Oscillator ......................................................................................... 22 5.2 Delay time control ........................................................................... 22 5.3 Soft-start ......................................................................................... 23 5.4 PWM comparator / slope compensation ......................................... 24 5.5 Current limit ..................................................................................... 24 5.6 Thermal protection .......................................................................... 25 6 Auxiliary sources .......................................................................... 26 7 Layout guidelines .......................................................................... 28 7.1 General guidelines for a PoE converter .......................................... 28 7.2 How to layout the PM8803 different ground pins............................. 28 8 Package information ..................................................................... 29 8.1 HTSSOP20 package information .................................................... 29 9 Revision history ............................................................................ 31 2/32 DocID018559 Rev 3