MC34670 Datasheet | Freescale Semiconductor

.. Freescale Semiconductor Advance Information Document Number: MC34670 Rev. 3.0, 12/2006 IEEE 802.3af PD With Current Mode Switching Regulator The 34670 bines a Power Interface Port for IEEE 802.3af Powered Devices (PD) and a high performance current mode switching regulator. It allows a designer to build PDs with a minimum of external ponents by means of integrating the required IEEE 802.3af functions and all functions necessary to build a high efficiency DC/DC converter. On the PD side the 34670 fully supports the IEEE802.3af standard and provides plete signature and power classification functions. It controls inrush current limiting and incorporates adjustable undervoltage lockout. The switching regulator provides excellent line and load regulation. It drives an external Power MOSFET with sense resistor. Features - - - - - - - - - - - - - Integrated IEEE 802.3af pliant Interface Signature Detection and Classification Functionality Integrated Isolation Switch Programmable Inrush Current Limiting Control Adjustable Undervoltage Lockout Input Voltage Range up to 80 V Current Mode Control Adjustable Oscillator Leading Edge Blanking Internal Slope pensation Circuitry Input Overvoltage Protection 50% Duty Cycle Limitation Pb-Free Packaging Designated by Suffix Code EG POWER OVER ETHERNET EG SUFFIX (PB-FREE) 98ASB42343B 20-PIN SOICW ORDERING INFORMATION Device MCZ34670EG/R2 Temperature Range (TA) -40°C to 85°C Package 20 SOICW PSE HUB OR SWITCH TX PHY RX RJ-45 ETHERNET APPLIANCE (PD) RX PHY TX HOST PROCESSOR PSE POWER CONTROLLER SWITCH -48V GND -48V CAT 5 CABLE PD POWER CONTROLLER ISOLATION SWITCH HOST CONTROLLER 48 V POWER SUPPLY DC/DC Figure 1. 34670 Simplified Application Diagram - This document contains certain information on a new product. Specifications and information herein are subject to change without notice. © Freescale Semiconductor, Inc., 2006. All rights reserved. INTERNAL BLOCK...