Texas Instruments LM5073EVAL

Overview

LM5073EVAL from Texas Instruments is an IEEE 802.3af-compliant Power over Ethernet (PoE) Powered Device (PD) evaluation board featuring the LM5073 PD interface IC, integrated hot-swap MOSFET (100V, 0.7Ω), programmable DC current limit (up to 800 mA), auxiliary power support (front/rear), and complementary open-drain control outputs for external DC-DC converters - used to validate PoE-powered IP cameras, VoIP phones, and wireless access points.

For engineers reviewing the LM5073EVAL datasheet, LM5073EVAL pinout, LM5073EVAL application, or LM5073EVAL equivalent, this evaluation platform enables rapid validation of IEEE 802.3af PD compliance, auxiliary power handover behavior, UVLO/PGOOD timing, inrush current limiting, and thermal shutdown response under real PoE cable impedance and transient conditions.

Technical Context

The LM5073EVAL implements the LM5073 IC in HTSSOP-14 EP package with exposed thermal pad, supporting full detection-classification-turn-on-inrush-normal operation sequence per IEEE 802.3af. It integrates signature resistor (24.5 kΩ), classification current programming (via RCLASS), UVLO (default 38 V rise / 31 V fall), and OVP (65 V nominal).

It supports dual auxiliary power modes: front auxiliary (FAUX-enabled, dominant/non-dominant selection via RAUX) and rear auxiliary (RAUX-configured), with independent enable thresholds (FAUX: 8.7 V typ; RAUX lower: 2.7 V, upper: 6.2 V). The board provides test points for VIN, VEE, RTN, nPGOOD, SD, nSD, and DCCL to verify timing, voltage margins, and current-limit accuracy.

Key Specifications

Availability

LM5073EVAL is available at Aetrix Electronics and suitable for PoE-powered IP surveillance systems, industrial IoT gateways, VoIP endpoint development, and enterprise wireless infrastructure requiring stable component supply, pre-validated reference design integration, and fast time-to-test.

Supply support for LM5073EVAL includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions across industrial, automotive, and communications markets.

The LM5073 product line delivers IEEE 802.3af-compliant PD interface ICs with auxiliary power flexibility, targeting cost-sensitive, high-reliability PoE endpoints such as security cameras, thin clients, and smart building sensors.

FAQ

What is the primary function of the LM5073EVAL evaluation board?

The LM5073EVAL evaluation board is a fully assembled and tested platform designed to demonstrate and validate the LM5073 IEEE 802.3af-compliant Powered Device (PD) interface IC. It enables engineers to verify detection, classification, inrush current limiting, UVLO behavior, auxiliary power handover, and power-good signaling - all critical for deploying reliable PoE-powered devices like IP cameras and VoIP phones. The LM5073EVAL includes all necessary passive components, test points, and layout optimized for EMC and thermal performance.

Does the LM5073EVAL support both front and rear auxiliary power configurations?

Yes, the LM5073EVAL supports both front and rear auxiliary power modes via dedicated FAUX and RAUX circuitry. Front auxiliary connects before the hot-swap MOSFET and can be configured as dominant or non-dominant relative to PoE; rear auxiliary connects after the MOSFET and enables true "powered-from-PoE" indication via nPGOOD. The LM5073EVAL includes jumpers and test points to configure RAUX threshold levels (2.7 V / 6.2 V) and validate seamless transitions without DC-DC converter interruption.

How is the DC current limit validated on the LM5073EVAL?

The LM5073EVAL allows precise validation of the LM5073's programmable DC current limit (150–800 mA) using the DCCL pin and an external resistor. Test points on VIN, RTN, and VEE enable direct measurement of hot-swap MOSFET drain-source voltage (VDS) and input current during steady-state operation. The board's layout supports accurate current sensing with shunt resistors and oscilloscope probing, confirming ±12% current limit accuracy across temperature (–40°C to +125°C) as specified in the LM5073 datasheet.

Can the LM5073EVAL be used to verify IEEE 802.3af compliance?

Yes, the LM5073EVAL is specifically designed to verify full IEEE 802.3af compliance, including signature resistance (24.5 kΩ), classification current (Class 0–4), UVLO thresholds (38 V rise / 31 V fall), inrush current limit (150 mA), and power-good assertion timing. It includes calibrated test points for VIN-to-VEE voltage monitoring during detection (1.5–10 V), classification (12–23.5 V), and normal operation (36–57 V), enabling pass/fail validation against TIA-1057 and IEC 62368-1 requirements.

What thermal management features are implemented on the LM5073EVAL?

The LM5073EVAL implements TI-recommended thermal design practices: the LM5073 HTSSOP-14 EP package is mounted on a large copper pour connected to the VEE net, with thermal vias beneath the exposed pad to inner ground planes. This achieves θJA ≈ 40°C/W, matching the datasheet specification. Thermal shutdown (165°C) and hysteresis (20°C) are verified using IR thermography and controlled ambient chamber testing - ensuring the LM5073EVAL accurately reflects real-world thermal behavior of the LM5073 in high-power PoE applications.