The KTA1137A 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 KTA1137A integrates input surge protection, a PD controller and a low-emission DC-DC controller. The KTA1137A implements all of the physical layer Powered Device (PD) functionality, as required by IEEE® 802.3af2005 and IEEE® 802.3at-2009 standards. This includes 2- event classification, Type 2 PSE detection indicator (ATDET), PD detection, under-voltage lockout (UVLO), and Hot-Swap FET integration.

The KTA1137A has been architected to address both EM emission concerns and surge/over-voltage protection in PoE applications. The chip implements many design features that minimize transmission of system common mode noise onto the Unshielded Twisted Pair (UTP). Onchip integration of surge protection provides faster response to surge events and limits stray surge current from passing through sensitive circuits, such as the Ethernet PHY. The device is designed to provide safe, low impedance discharge paths directly to the earth ground, resulting in superior reliability and circuit protection.


  • 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
  • Robust Type 2 PSE detector with proprietary digital filtering for line noise to eliminate false positives
  • IEC 61000-4-2/3/4/5/6 requirements for EMC Compliance
  • Integrated Surge Protection for 15kV/8kV System level ESD Compliance
  • Exceptional EMI performance
  • Programmable DC current limit up to 730mA for 30W applications
  • Seamless support for local power, down to 9.5V
  • Low Rds-on Hot-Swap FET (typical 0.6Ω)
  • Integrated Short-Circuit Protection
  • Over temperature protection
  • 5×5 mm, 20 lead QFN Package
  • Industrial temperature range (-40°C to +85°C)


  • 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

Packaging Information

Package Dimensions Bumps Package Code
TQFN55-20 5.00mm x 5.00mm x 0.90mm 20 UAB


Vin (min)  Vin (max)  PoE PD Support Control Topology Number of Output Rails High Voltage Isolation
9.5V 57V 802.3af&at HW Mode Flyback 1 External

Technical Documentation

Description Documents Type
Package Outline DrawingTQFN55-20 UAB PODPDF

Evaluation Tools

Documents Type
User ManualPDF
Quick Start GuidePDF
Bill of MaterialsXLSX
3D BoardPDF


Part Number Marking Operating Temperature Package
KTA1137AEUAB-TR OGYWZ -40°C to +85°C QFN55-20
Purchase Options
Buy from Digi-Key
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