Interface and PWM Controller 20-Pin HTSSOP EP T/R

The PM8803 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. The PoE/PoE+ interface incorporates all the functions required by the IEEE 802.3at including detection, classification, undervoltage lockout (UVLO) and in-rush current limitation.The PM8803 specifically performs IEEE802.3at Layer1 hardware classification, providing an indication of Type 2 PSE successful detection to the rest of the system.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 prevalence of the auxiliary source with respect to 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 at all load conditions supporting flyback, forward, forward with active clamp converters and synchronous rectification.

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 O, 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 startup 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