DAK-86: POE, 6.6 W, 3.3V @ 2.0A, 33 ~ 57 V in

Summary

A flyback topology was used to minimize circuit board size, parts count and cost. This topology also provides excellent operating efficiency across the input voltage range.

The DPA423G IC implements PWM control of the internal power MOSFET and initiates a soft start-up function when it first powers up. The IC also monitors die temperature as part of its over-temperature protection function and also monitors the input voltage as part of its under-voltage detection and overvoltage shutdown functions.

The integrated 220 V MOSFET provides excellent switching characteristics at the selected 400 kHz operating frequency. The MOSFET and controller consume very little power, giving good efficiency across the entire input voltage operating range.

Specifications

Manufacturer	Power Integrations
Category	Power Management
Sub-Category	POE - Power Over Ethernet
Eval Board Part Number	596-1195-ND
Eval Board Supplier	Power Integrations
Eval Board	Board not Stocked
Compliance	IEEE 802.3af (802.3at Type 1)
Outputs and Type	1 Isolated
Voltage Out	3.3 V
Current Out	2 A
Voltage In	33 ~ 57 V
Efficiency @ Conditions	>72%, 48V in, 3.3V @ 0.6 ~ 2 A
Internal Switch	Yes
Features	Current Limit (Adj. or Fixed) Light Load Mode Over Voltage Protection Short Circuit Protection Soft Start Thermal Protection Under Voltage Protection, Brown-Out
Switching Frequency	400 kHz
Component Count + Extras	61 + 2
Application / Target Market	PoE, Power Over Ethernet
Design Author	Power Integrations
Main I.C. Base Part	DPA423
Date Created By Author	2006-04
Date Added To Library	2011-05