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Texas Instruments LM5073MHX/NOPB
- Part No.:
- LM5073MHX/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Power Over Ethernet (PoE) Controllers
- Package:
- 14-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM5073MHX/NOPB.pdf
- Description:
- IC POE CNTRL 1 CHANNEL 14HTSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,883
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Product details
Overview
LM5073MHX/NOPB from Texas Instruments is a fully IEEE 802.3af-compliant Powered Device (PD) interface IC with integrated 100V hot-swap MOSFET (RDS(ON) = 0.7 Ω), programmable DC current limit up to 800 mA, and dual auxiliary power support (front/rear). It enables PoE-powered IP phones, wireless access points, and network cameras by managing detection, classification, inrush control, and power-good signaling for external DC-DC converters.
For engineers reviewing the LM5073MHX/NOPB datasheet, LM5073MHX/NOPB pinout, LM5073MHX/NOPB application, or LM5073MHX/NOPB equivalent, this page delivers verified technical context, exact pin functions, real-world auxiliary power configuration trade-offs, thermal shutdown behavior at 165°C, and validated alternatives for PoE PD designs requiring >15W input capability.
Technical Context
The LM5073MHX/NOPB implements a complete IEEE 802.3af PD front-end with integrated signature resistor (24.5 kΩ), programmable UVLO (default 38 V rise / 31 V fall), and line over-voltage protection (65 V threshold). Its hot-swap MOSFET operates up to 100 V with 0.7 Ω RDS(ON), enabling robust surge suppression and compatibility with lower-rated DC-DC converters.
It supports three concurrent power sources: PoE (via VIN/VEE), front auxiliary (FAUX-enabled, ≥13 V), and rear auxiliary (RAUX-enabled, ≥9 V), with dominant/non-dominant selection logic. Control outputs (nSD/SD/nPGOOD) provide complementary open-drain signals with 30 µs default power-good delay and 1.5 V VDS threshold for accurate DC-DC enable sequencing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VIN Operating Range | 9 V to 70 V - supports full IEEE 802.3af PoE range plus margin for cable drop and transients |
| Hot-Swap MOSFET Rating | 100 V / 0.7 Ω - simplifies TVS selection and handles hot-swap surges without external FET |
| DC Current Limit | Programmable 150–800 mA via DCCL pin - enables scaling beyond Class 3 (up to ~38 W input) |
| UVLO Threshold | Default 38 V (rise) / 31 V (fall) - ensures reliable startup at 42 V min and hold-up down to 36 V per spec |
| Thermal Shutdown | 165 °C with 20 °C hysteresis - protects against sustained overload or poor PCB heat sinking |
| Auxiliary Power Support | Front (≥13 V, FAUX) and rear (≥9 V, RAUX) - allows AC adapter or solar backup without disabling PoE detection |
| Classification Capability | IEEE 802.3af Classes 0–4 via RCLASS resistor - enables PSE power allocation negotiation |
Pinout & Package
Package: HTSSOP-14 EP (Exposed Pad), thermally enhanced for PoE front-end dissipation; exposed pad must be connected to VEE plane for optimal thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 UVLORTN | UVLO resistor divider return | Reference node for external UVLO programming; internal 55–150 Ω pull-down sets hysteresis |
| 2 UVLO | UVLO threshold programming | Accepts external resistor divider; overrides default 38 V/31 V thresholds when pulled above 12.5 V |
| 3 VIN | PoE/auxiliary positive input | Primary high-side supply node; rated to 100 V absolute max; feeds hot-swap MOSFET source |
| 4 RCLASS | Classification current setting | Connects to VEE via resistor to set IEEE 802.3af class (0–4); disabled during auxiliary operation |
| 5 FAUX | Front auxiliary enable | Active-high input; enables front auxiliary path when VIN < 13 V; dominates PoE if both present |
| 6 DCCL | DC current limit programming | Resistor-to-VEE sets limit from 150–800 mA; open = 440 mA default |
| 7 VEE | Negative return (PoE/aux) | Common return for PoE lines and front auxiliary; connects to current-steering bridge cathode |
| 9 RTN | DC-DC converter return | Drain-side return for hot-swap MOSFET; connects to DC-DC input capacitor negative terminal |
| 11 nPGOOD | Power-good flag output | Open-drain, active-low; asserts when VDS < 1.5 V; drives LED or RC delay timer for DC-DC enable |
| 12 nSD | Active-low DC-DC shutdown | Open-drain, high-impedance when nPGOOD > 2.5 V; used to disable DC-DC controller during fault |
| 13 SD | Active-high DC-DC shutdown | Open-drain, low when nPGOOD < 2.5 V; complements nSD for flexible controller interface |
| 14 RAUX | Rear auxiliary enable/select | Dual-function: enables rear auxiliary (≥9 V) and selects dominant/non-dominant mode vs PoE |
Key Features
| Feature | Design Value |
|---|---|
| Integrated PD signature resistor | 24.5 kΩ ±5% - eliminates external component, ensures IEEE 802.3af detection compliance without calibration |
| Programmable inrush current limit | 150 mA fixed - prevents PoE PSE tripping during DC-DC input capacitor charge; no external timing components needed |
| Dual auxiliary power architecture | Front (FAUX) and rear (RAUX) paths - enables seamless failover between PoE and AC/solar without reclassification or reset |
| Complementary DC-DC control outputs | nSD (active-low) + SD (active-high) - supports any controller with enable/disable polarity; eliminates level-shifting logic |
| Thermal shutdown with hysteresis | 165°C trip / 145°C recovery - prevents latch-up during overload; allows safe auto-restart after cooling |
| Line over-voltage protection | 65 V OVP threshold - disables hot-swap MOSFET before downstream DC-DC converter damage occurs |
Applications
| IP Phone Power Management | Wireless Access Point (WAP) |
|---|---|
Use Scenario: Dual-input VoIP phone drawing power from PoE switch while supporting AC adapter backup during network outages. IC Role / Device Role / Timing Role: LM5073MHX/NOPB acts as primary PD interface, performing IEEE 802.3af detection/classification, hot-swap control, and auxiliary source arbitration. Use Value: Enables uninterrupted operation using FAUX-driven front auxiliary mode; maintains call continuity without re-negotiation when switching sources. |
Use Scenario: High-density enterprise WAP requiring >15W PoE input (Class 4) with thermal headroom for 24/7 operation in ceiling-mounted enclosures. IC Role / Device Role / Timing Role: LM5073MHX/NOPB provides 800 mA programmable current limit and 165°C thermal shutdown to sustain full RF output under ambient temperatures up to 70°C. Use Value: Eliminates need for external current-sense amplifier or discrete thermal cutoff; reduces BOM count by integrating classification, UVLO, and OVP. |
| Network Video Camera | Industrial IoT Gateway |
Use Scenario: Outdoor PTZ camera powered via PoE with solar panel backup; requires rear auxiliary (RAUX) mode to avoid re-detection when sun rises. IC Role / Device Role / Timing Role: LM5073MHX/NOPB serves as intelligent power arbiter, using RAUX to prioritize solar input while retaining PoE signature for remote management. Use Value: Prevents network disconnection events during solar transition; nPGOOD LED indicates "Powered from PoE" status for field diagnostics. |
Use Scenario: Edge gateway aggregating sensor data in factory settings, needing PoE + battery backup with precise power-good sequencing for MCU boot. IC Role / Device Role / Timing Role: LM5073MHX/NOPB generates synchronized SD/nSD signals and 30 µs nPGOOD delay to ensure clean DC-DC startup before processor initialization. Use Value: Guarantees deterministic boot sequence across power sources; avoids brown-out resets during PoE transient dips. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Powered Device interface applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT4275IMS#PBF | IEEE 802.3at (PoE+) compliant; 30 V max VIN; no integrated hot-swap FET; requires external MOSFET | Targets higher-power (30 W) applications but lacks 100 V rating and auxiliary support | Select when upgrading to PoE+ and external FET layout is acceptable; not drop-in for LM5073MHX/NOPB's 100 V or auxiliary features |
| MAX5974AETG+ | IEEE 802.3af compliant; 60 V max VIN; integrated 0.5 Ω FET; no rear auxiliary (RAUX) support | Suitable for cost-sensitive Class 2/3 devices but cannot handle >60 V transients or dual-path arbitration | Choose for compact designs where 60 V rating suffices and only front auxiliary is needed; pinout and control logic differ significantly |
Compared with LT4275IMS#PBF and MAX5974AETG+, the LM5073MHX/NOPB uniquely combines 100 V operation, integrated 0.7 Ω hot-swap FET, and dual (front/rear) auxiliary arbitration-enabling robust, high-power PoE designs without external FETs or complex source-selection logic.
Availability
LM5073MHX/NOPB is available at Aetrix Electronics and suitable for IP phones, wireless access points, network cameras, and industrial gateways requiring stable component supply, long-term lifecycle support, and guaranteed traceability for PoE infrastructure deployments.
Supply support for LM5073MHX/NOPB 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 leader specializing in analog, embedded processing, and power management technologies, with decades of leadership in power-over-Ethernet interface solutions.
The LM5073MHX/NOPB belongs to TI's PoE PD interface product line, engineered specifically for IEEE 802.3af-compliant powered devices that demand high-voltage resilience, auxiliary power flexibility, and simplified system-level power sequencing.
FAQ
What is the maximum input voltage rating for the LM5073MHX/NOPB?
The LM5073MHX/NOPB has an absolute maximum VIN rating of 100 V, enabling robust protection against Ethernet cable transients and simplifying TVS diode selection. Its operating range is specified from 9 V to 70 V, covering full IEEE 802.3af PoE (36–57 V) with margin for worst-case cable drop and surge events. This 100 V rating allows use with lower-voltage-rated DC-DC converters downstream.
How does the LM5073MHX/NOPB support auxiliary power sources?
The LM5073MHX/NOPB supports two auxiliary configurations: front auxiliary (enabled via FAUX pin, ≥13 V) and rear auxiliary (enabled via RAUX pin, ≥9 V). Front auxiliary dominates PoE and bypasses detection/classification; rear auxiliary coexists with PoE signature and enables "Powered from PoE" indication via nPGOOD. Both modes maintain IEEE 802.3af compliance when PoE is active.
Can the LM5073MHX/NOPB be used in IEEE 802.3at (PoE+) applications?
The LM5073MHX/NOPB is IEEE 802.3af-compliant only and not certified for IEEE 802.3at (PoE+). While its 800 mA programmable current limit exceeds Class 3 (600 mA), it lacks the 25.5–30 W power negotiation protocol and dual-signature detection required for PoE+. For PoE+ designs, TI recommends the LM5072 or LT4275 series instead.
What is the function of the nPGOOD pin on the LM5073MHX/NOPB?
The nPGOOD pin on the LM5073MHX/NOPB is an open-drain, active-low power-good flag that asserts low when the hot-swap MOSFET's drain-to-source voltage falls below 1.5 V-indicating full charging of the DC-DC input capacitors. It drives LEDs for status indication and controls SD/nSD shutdown outputs; adding a capacitor to RTN creates a user-programmable delay (e.g., 100 nF = 5 ms) to prevent false DC-DC disable during transients.
Does the LM5073MHX/NOPB require external components for IEEE 802.3af compliance?
The LM5073MHX/NOPB integrates all core IEEE 802.3af functions: signature resistor (24.5 kΩ), classification current reference, UVLO (default 38 V/31 V), inrush current limit (150 mA), and thermal shutdown (165°C). Only three external components are mandatory: RCLASS (for class selection), DCCL (for current limit), and UVLORTN/UVLO resistors (if custom UVLO is needed). No external MOSFET or sense resistor is required.
LM5073MHX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 14-PowerTSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Controller (PD)
- Number of Channels:
- 1
- Power - Max:
- 12.95 W
- Internal Switch(s):
- Yes
- Auxiliary Sense:
- Yes
- Standards:
- 802.3af (PoE)
- Voltage - Supply:
- 9V ~ 70V
- Current - Supply:
- 2mA
- Operating Temperature:
- -40°C ~ 125°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-HTSSOP
LM5073MHX/NOPB FAQ
1.How can I place an order for LM5073MHX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM5073MHX/NOPB on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LM5073MHX/NOPB reliable?
The price and inventory of LM5073MHX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM5073MHX/NOPB is usually 5 days.
3.What payment methods are accepted for LM5073MHX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM5073MHX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM5073MHX/NOPB?
LM5073MHX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM5073MHX/NOPB order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LM5073MHX/NOPB?
For technical support, including LM5073MHX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM5073MHX/NOPB requirements.
6.How does Aetrix verify that LM5073MHX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM5073MHX/NOPB products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM5073MHX/NOPB meets industry standards.
7.What is the process for return or replacement of LM5073MHX/NOPB?
All LM5073MHX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM5073MHX/NOPB, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LM5073MHX/NOPB part is unused and in its original packaging.
Return procedure for LM5073MHX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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