PM8801 High-efficiency, IEEE 802.3at compliant, integrated PoE-PD interface and PWM controller Datasheet - production data Description The PM8801 integrates a standard compliant Power over Ethernet (PoE) interface and a current mode PWM controller to simplify the design of the power supply sections of all powered devices. HTSSOP24 The PoE/PoE+ interface incorporates all the functions required by the IEEE 802.3at including Features detection, classification, undervoltage lockout IEEE 802.3at compliant PD interface (UVLO) and inrush current limitation. Works with power supplied from Ethernet LAN The PM8801 specifically performs IEEE802.3at cables or from local auxiliary sources Layer1 hardware classification, providing an indication of type 2 PSE successful detection to Successful IEEE802.3at Layer1 classification the rest of the system. indicator Integrated 100 V, 0.45 , 1 A hot-swap The PM8801 has been designed to work with MOSFET power either from the Ethernet cable connection or from an external power source such as a wall Accurate 140 mA typ. inrush current level adapter, ensuring prevalence of the auxiliary Programmable classification current source with respect to the PoE interface. Sleep mode with LED indicator and Maintain The DC/DC section of the PM8801 features a Power Signature (MPS) programmable oscillator frequency, an adjustable Precise DC current limit set at 640 mA typ. slope compensation, dual complementary low- side drivers with programmable delay time and Integrated high-voltage startup bias regulator internal temperature sensor. Thermal shutdown protection The PM8801 targets high-efficiency conversion at Current mode pulse width modulator all load conditions supporting flyback, forward, Programmable oscillator frequency forward active clamp and synchronous 80% maximum duty cycle with internal slope rectification. compensation Support for flyback, forward, forward active Table 1. Device summary clamp, flyback with synchronous rectification Part number Package Packing PM8801 Tube Applications HTSSOP24 PM8801TR Tape and reel VoIP phones, WLAN AP WiMAX CPEs Security cameras PoE/PoE+ Powered device appliances July 2013 DocID018560 Rev 2 1/37 This is information on a product in full production. www.st.com 37Contents PM8801 Contents 1 Typical application circuit and block diagram 6 1.1 Application circuits . 6 1.2 Block diagrams 8 2 Pin descriptions and connection diagram 10 3 Electrical specifications . 13 3.1 Absolute maximum ratings 13 3.2 Thermal data 13 3.3 Electrical characteristics 14 4 PD interface . 19 4.1 Detection . 19 4.2 Classification 19 4.3 Indication of successful 2-event classification . 20 4.4 Undervoltage lockout 22 4.5 Inrush and DC current limiting . 22 4.6 Sleep mode / MPS mode . 23 4.7 LED driving 24 4.8 Wakeup from sleep mode 26 4.9 High-voltage startup regulator . 26 4.10 5 V bias regulator . 27 5 PWM controller 28 5.1 Oscillator . 28 5.2 Delay time control . 28 5.3 Soft-start 30 5.4 PWM comparator / slope compensation . 30 5.5 Current limit . 30 5.6 Thermal protection 31 2/37 DocID018560 Rev 2