Product Brief

AS1135 Product Brief

March 2008

Page 1

AS1135

13-30W IEEE 802.3af/at (Draft 2.0)

Powered Device with Integrated

DC-DC Controller

General Description

The AS1135 is a single-chip, highly integrated CMOS solution

for Power over Ethernet (PoE) Powered Devices requiring input

power of up to 30Watts. Applications include Voice over IP

(VoIP) Phones, Wireless LAN Access Point, Security Cameras,

WiMax Terminals, Point of Sales Terminals, RFID Readers,

Thin Clients and Notebook computers.

The AS1135 integrates input Surge Protection, a PD controller,

and a low-emission DC-DC controller. The AS1135 implements

all the physical layer Powered Device (PD) functionality as

required by the IEEE® 802.3af-2005 and IEEE® 802.3at (Draft

2.0) standards. This includes 2-event classification, Type2 PSE

detection indicator (ATDET) in addition to PD detection, under-

voltage lockout, and hot-swap FET integration.

The AS1135 has been architected and designed to address

both EMI emission concerns and surge/over-voltage protection

in POE applications. The AS1135 implements many design

features that minimizes transmission of system common-mode

noise on to the UTP. On-chip integration of surge protection

provides faster ressponse to surge events and limits stray surge

current from passing through sensitive circuits, such as the

Ethernet PHY device. The device is designed to provide a safe

low impedance discharge paths directly back to the earth

ground, resulting in superior reliability and circuit protection.

By using high-volume standard CMOS technology, Akros

enables its customers to implement higher performance PoE

devices with low cost and a small footprint.

Features

The AS1135 is fully integrated and architected at a system level

to provide the following features:

•

Fully supports IEEE® Std. 802.3af-2005 and supports

IEEE® Std. 802.3at (Draft 2.0) power requirements

•

Supports 2-Event Physical Layer Classification for

802.3at (Draft 2.0) higher power PD applications

•

Provides Type 2 PSE detection per 802.3at (Draft 2.0)

•

Meets IEC 61000-4-2/3/4/5/6 for EMC Compliance

•

Meets IEC 60950 isolation requirements

•

Integrated DC-DC controller, provides exceptional

EMI performance

•

Programmable DC current limit up to 800mA

•

Provides seamless support for local power 10~57V

•

Low Rds-on hot-swap FET (typical 0.8Ω)

•

Over temperature protection

•

Industrial temperature range, -40ºC to +85ºC

•

5x5 mm, 20 lead QFN Package, RoHS compliant

Typical Applications

•

Pan, Tilt and Zoom (PTZ), Security and Web Cameras

•

Voice over IP (VoIP) phones

•

Wireless LAN Access Points, WiMax Terminals

•

Point of Sale (PoS)Terminals, RFID Terminals

•

Thin Clients and Notebook Computers

•

Fiber to the Home (FTTH) Terminals

Example Application Diagram

Figure 1: Typical Application Diagram for PoE PD (Flyback converter)