EPR-86 Datasheet, PDF (9/28 Pages) Power Integrations, Inc. – Engineering Prototype Report for EP 86 - 6.6 W Multi-Class Powered Device (PD) for Power over Ethernet (PoE) Using DPA-Switch-(DPA423G)

13-Apr-2006
EP-86 – 6.6 W, 3.3 V, 2 A PoE Powered Device
Q2 is on, and sinks additional current from the resistor (R5) that connects the L pin to the
DC input voltage. The value of R14 was selected so that an extra 10 µA is drawn at
startup, which increases the turn-on threshold voltage to 41 VDC typical. However,
because Q2 turns off after start-up, the UV turn-off threshold stays at 34 VDC (see DI-
101 for more details).
Figure 7 – L-pin current without and with the widened UV hysteresis circuit.
Page 9 of 28
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