Isolated 4-port power over ethernet PSE controller passes conformance tests


Analog Devices announces the Power by Linear™ LTC4291/92 isolated 4-port power source equipment (PSE) controller chipset, the first of its kind to pass a series of IEEE 802.3bt (PoE++) Power over Ethernet (PoE) conformance tests administered by Sifos Technologies.  PoE naturally presents system and network engineers with PSE evaluation challenges. PSEs are multichannel, intelligent DC power sources that are activated and deactivated through standardized processes without disrupting traditional Ethernet data transmission. At the same time, compliance testing is complicated by requirements to operate over several delivery and polarity configurations.

The Sifos 24-port PSA-3000 PowerSync analyzer equipped with multiple 2-port PSA-3202 test blades provides complete automated testing and analysis of LTC4291/92-based PSEs. Rigorous compliance test suites augmented by specialized analysis features validated the LTC4291/92 to the IEEE 802.3at (PoE+) standard, the upcoming 802.3bt standard, and other proprietary specifications.  These scalable design and test solutions build in extensive PoE knowledge and years of experience, reducing time-to-market and enabling deployment of IEEE 802.3bt PoE networks as the standard approaches ratification in 2018.

In testing performed by Analog Devices, the LTC4291/92 PSE chipset passed a wide variety of tests as the PSA-3000/3202 solution emulated a variety of IEEE 802.3bt PDs (powered devices).  Continuous 90W 4-pair PSE loading capability ensured that the PSE could handle 802.3bt’s 71.3W maximum PD power level in either single- signature or dual-signature PD configurations.  The LTC4291/92 correctly identified all physical layer classes (up to 5 events) as required by the new Type 3 and Type 4 PDs, as well as the backward compatible Type 1 and Type 2 PDs. For PSEs that use the link layer discovery protocol (LLDP), the PSA-3000/3202 can also emulate and analyze this type of power negotiation.

Customers configure and interact with the devices using provided GUIs and scripting environments. The LTC4291/92 is supported with lab-tested schematics, complete reference designs, the QuikEval™ GUI and example code, while the

PSA-3000/3202 is extended with the PSA Interactive GUI and PowerShell PSA scripting environment.

The LTC4291/92 chipset is offered in commercial and industrial temperature ranges.  The LTC4291 digital controller is offered in a RoHS-compliant 24-pin 4mm x 4mm QFN package, while the LTC4292 analog controller is in a 40-pin 6mm x 6mm QFN package. The LTC4291/92 is Analog Devices’ first 802.3bt PSE controller and provides an upgrade path for the popular LTC4266 4-port 802.3at PSE controller.  Please visit for more product information.