13W/30W 802.3af/at PoE PD with 2-event classification, ATdetect and Integrated DC-DC Controller

    * NOTE - AS1138 recommended for new PoE PD designs.

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 digital 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 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.



  • 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



The AS1135 is fully integrated and architected at a system level to provide the following features:

  • Full support of both IEEE®  Std. 802.3af-2005 and IEEE®  Std. 802.3at-2009 power requirements
  • “2-Event” classification for 802.3at higher power PDs
  • Type 2 PSE detection per 802.3at standard
  • IEC 61000-4-2/3/4/5/6 requirements for EMC Compliance
  • Integrated Surge Protection for 15kV/8kV System level ESD Compliance
  • Integrated DC-DC controller for exceptional  EMI performance
  • Programmable DC current limit up to 720mA for 30W applications
  • Seamless support for local power, down to 9.5V
  • Implemented in robust 100V automotive process
  • Low Rds-on Hot-Swap FET (typical 0.8Ω)
  • Over temperature protection
  • Industrial temperature range, -40º to +85ºC
  • 5x5 mm, 20 lead QFN Package, RoHS compliant


Block Diagram

Akros Silicon AS1135



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