PoE controller supports any DC/DC converter topology

National Semiconductor Corp. has introduced a PoE powered device (PD) controller with adjustable output current level and the ability to interface with any DC/DC converter topology.

Touted as the industry's highest power PoE controller, National claims that LM5073 integrates a programmable interface port including a hot-swap controller that exceeds the standard IEEE 802.3af specifications, allowing designers to operate PoE appliances at power levels of 30W or more. For greater flexibility, LM5073 separates the PD interface from the DC/DC converter to support a wide variety of isolated and non-isolated DC/DC converter topologies. Applications include IP telephony, remote security cameras, card readers, wireless access points, PoE-enabled industrial automation systems and PoS terminals.

The LM5073 PoE controller supports PD designs that are fully compliant with the IEEE 802.3af standard. If more power is required, the low RDS(on) hot-swap MOSFET and programmable DC current limit extend the range of LM5073 applications to more than twice the power level of IEEE 802.3af compliant devices. LM5073 also provides the flexibility for the PD to accept power from unregulated auxiliary sources such as AC adapters and solar cells in a variety of configurations. The 100V maximum voltage rating simplifies selection of the voltage suppressor that protects the PD from network transients.

Offered in a 14-pin TSSOP with exposed pad for improved thermal performance, LM5073 integrates a 100V, 700mΩ, N-channel MOSFET as well as the PD signature and under-voltage lockout resistors. It provides configurable front and rear auxiliary inputs that accept power from AC adapters to reduce the power draw on the PoE power sourcing equipment. Complementary control outputs provide a flexible interface to the best DC-DC converter topology for the particular application. For non-isolated applications, the LM5073 can be paired with National's LM5007 and LM5010 buck regulators or LM5574, LM5575 and LM5576 high-voltage SIMPLE SWITCHER product family. For higher-power isolated systems, LM5073 can be paired with National's LM5020 or LM5026 PWM controllers.

The new LM5073 is available now and priced at $1.30 in 1,000-unit quantities.