Texas Instruments TPS2379DDAR

Overview

TPS2379DDAR from Texas Instruments is an IEEE 802.3at Type-2 Powered Device (PD) interface IC with integrated 100-V, 0.5-Ω hot-swap MOSFET, 140-mA inrush current limit, 1-A operating current limit, and auxiliary gate driver for external pass transistor control. It enables high-power PoE applications such as security cameras and multiband access points by managing detection, classification, and power handoff.

For engineers reviewing the TPS2379DDAR datasheet, TPS2379DDAR pinout, TPS2379DDAR application, or TPS2379DDAR equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative parts with functional distinctions, and supply-chain support details specific to industrial PoE system development.

Technical Context

The TPS2379DDAR implements full IEEE 802.3at Type-2 hardware classification using a programmable CLS pin with 1270 Ω–63.4 Ω resistor options, supports dual-stage current limiting (140 mA inrush → 1 A steady-state), and features UVLO thresholds at 38.1 V (rising) and 32 V (falling). Its GATE output drives external MOSFETs after inrush completion, while CDB provides open-drain converter disable signaling referenced to RTN.

It integrates thermal shutdown (145 °C trip), current-limit foldback, and robust 100-V absolute maximum rating on RTN/VDD. The device operates across –40 °C to +125 °C junction temperature, with PowerPAD HSOP-8 package enabling 28.8 °C/W junction-to-board thermal resistance for sustained 0.85-A continuous conduction.

Key Specifications

Pinout & Package

TPS2379DDAR uses an HSOP-8 (DDA) package with exposed PowerPAD thermally connected to VSS. The 4.89 mm × 3.90 mm body requires large VSS copper fill for thermal management and maintains 0.025″ clearance from high-voltage traces (e.g., VDD).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar IEEE 802.3at PD interface applications.

Compared with TPS23753APWPR and LT4275IMS#PBF, the TPS2379DDAR uniquely combines Type-2 hardware classification, auxiliary GATE driver, and 100-V robustness-making it the only option among the three for scalable, standards-compliant 30–60 W PoE endpoints requiring external pass transistor support.

Availability

TPS2379DDAR is available at Aetrix Electronics and suitable for security cameras, multiband access points, VoIP telephones, and pico-base stations requiring stable component supply, long-term lifecycle assurance, and traceable sourcing for industrial PoE deployments.

Supply support for TPS2379DDAR 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 connectivity technologies, with decades of leadership in power management and industrial interface solutions.

The TPS2379DDAR belongs to TI's Power over Ethernet (PoE) PD controller product line, engineered specifically for IEEE 802.3at Type-2 compliance, high-voltage robustness, and seamless integration with external power stages in professional AV, telecom, and IoT edge devices.

FAQ

What is the function of the GATE pin on the TPS2379DDAR?

The GATE pin on the TPS2379DDAR is an auxiliary gate driver output that sources 38 µA to turn on an external N-channel MOSFET after inrush current limiting completes. It remains high during normal operation but pulls low within 365 µs of overcurrent or thermal shutdown. This allows the TPS2379DDAR to scale beyond its internal 0.85-A limit while maintaining precise control over external power delivery - a critical capability for 30–60 W PoE applications where the TPS2379DDAR serves as the primary interface controller.

How does the TPS2379DDAR implement IEEE 802.3at Type-2 classification?

The TPS2379DDAR implements IEEE 802.3at Type-2 classification through hardware-based dual-event detection: it first performs standard resistive classification (via CLS pin and RCLS resistor), then verifies Type-2 capability by detecting enhanced PSE signaling during the second classification event. Only upon successful completion does it assert the T2P pin low. This hardware-only method ensures deterministic, firmware-free compliance - unlike software-dependent alternatives - and is explicitly validated in the TPS2379DDAR datasheet SLVSB98A section 8.3.6 and Figure 15.

What is the purpose of the CDB pin on the TPS2379DDAR?

The CDB pin on the TPS2379DDAR is an open-drain, active-low converter disable output that holds downstream DC/DC controllers in soft-start or shutdown until bulk capacitance charging is complete and the GATE driver has fully enhanced the external MOSFET. It pulls low during inrush and releases only after GATE exceeds 6 V - preventing nuisance overcurrent faults during startup. This behavior is defined in TPS2379DDAR datasheet SLVSB98A section 8.3.1 and Figure 16, ensuring safe, sequenced power-up in high-power PoE systems.

Can the TPS2379DDAR operate without an external MOSFET?

Yes, the TPS2379DDAR can operate standalone using only its internal 0.5-Ω MOSFET to deliver up to 0.85 A continuously (≈30 W at 37 V), sufficient for Class 3 (12.95 W) and Class 4 (25.5 W) devices. Its GATE pin is optional - left unconnected when external scaling isn't needed. However, for >30 W loads (e.g., PTZ cameras or dual-radio APs), an external MOSFET driven by the TPS2379DDAR's GATE output is required to avoid thermal saturation and maintain reliability, as confirmed in the TPS2379DDAR datasheet SLVSB98A section 8.3.4 and Figure 17.

What thermal performance can be expected from the TPS2379DDAR in HSOP-8 package?

The TPS2379DDAR in HSOP-8 (DDA) package achieves 28.8 °C/W junction-to-board thermal resistance (RθJB) when the PowerPAD is properly soldered to a large VSS copper area, per datasheet SLVSB98A section 6.4. This enables continuous 0.85-A operation at +125 °C ambient in well-designed layouts. Thermal shutdown activates at 145 °C with 20 °C hysteresis, allowing auto-recovery. For higher loads, external MOSFET use shifts heat dissipation away from the TPS2379DDAR die - a key design advantage documented in section 8.3.4.1.