GreenEdge™ IEEE802.3af/802.3at (13W-30W) PoE PD Controller with HV Isolation

The AS1851 integrates Akros GreenEdge™ High Voltage Isolation technology with Power-over-Ethernet (PoE) PD and Synchronous DC-DC power conversion technology.

The AS1851 includes a 13W/25W (Type 1 and Type 2) IEEE®802.3af/at compliant PD integrated with high-voltage isolation and a digital power Synchronous DC-DC converter.


  •   Voice-over-IP (VoIP) phones
  •   Wireless LAN & WiMAX access points (WAP)
  •   Pan, Tilt, Zoom (PTZ) Cameras, IP cameras
  •   Thin-client and notebook computers
  •   Fiber-to-the-home (FTTH) terminals



Digitally Isolated Programmable Power

   PoE PD Controller

  • Type 1 IEEE® 802.3af and Type2 IEEE® 802.3at Compliant PD for 13-30W applications
  • Automatic PoE-Plus (Type 2) detection in H/W and I2C Modes
  • Low Resistance PD Power FET Switch (0.5 ohm typical)

   Primary-Side DC-DC Controller

  • High-efficiency DC-DC Controller with Digital Optimization
  • Primary-Secondary High-voltage integrated Digital Isolation
  • Programmable Primary Clock Frequency
  • Local-power operation down to 9.5V

  Secondary-Side Power Outputs

  • Programmable PWM Frequencies synched to External Clock
  • Synchronous Controller with programmable power-FET timing for high efficiency at both light and full load

 Power Management

  • Hardware programmable start-up power sequencing
  • Primary-side power monitoring & control from Secondary side
  • Output Power-Good logic output
  • Primary GPIO/ADC controlled via Secondary GPIO or I2C
  • 5V µC-compatible with interrupt on alarm services
  • Programmable watchdog timer

EMC Compliance and Protection

  • Slew-rate-controlled power drivers
  •  External Sync clock option
  • Optional spread-spectrum clocking, SW controlled
  • Over-current, Under/Over-voltage and Short-circuit Protection
  • High-temperature warning and shutdown
  • Meets IEC 61000-4-2/3/4/5/6, IEC60747, IEC 60950, DIN EN60747-5-2 (VDE0884), & UL1577 requirements for EMC compliance and basic isolation to 2120 VDC (1500 VRMS)



Block Diagram



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