Texas Instruments TPS2383APMRG4

Overview

TPS2383APMRG4 from Texas Instruments is a Power Sourcing Equipment Power Manager (PSEPM) IC compliant with IEEE 802.3af PoE standard, designed for Ethernet port power control in mid-span injectors and switches. It supports two-point 25-kΩ resistor discovery, capacitive legacy load detection, and 12-bit per-port current/voltage acquisition across eight ports. Its controlled di/dt ramp-up/down reduces EMI during PD power delivery.

For engineers reviewing the TPS2383APMRG4 datasheet, TPS2383APMRG4 pinout, TPS2383APMRG4 application, or TPS2383APMRG4 equivalent, key selection considerations include its I²C slave interface with 5-bit address selectability, opto-coupler-compatible SDA/SCL lines for ground isolation, dual-color LED drivers for port status indication, and external N-channel MOSFET gate drive capability up to 10 V.

Technical Context

The TPS2383APMRG4 implements a master sequencer state machine that cycles through eight Ethernet ports, coordinating shared analog resources-including a 12-bit A/D converter, ramp control circuitry (CR/CT/CINT), and discovery/classification voltage loops-while each port maintains independent fault monitoring and control logic. Its architecture separates discovery (25-kΩ + capacitive), classification (17.5-V, 12-bit current measurement), and powered-mode operation (425-mA max ramp, <400-mA sustained).

It uses external 0.5-Ω current-sense resistors per port for accurate overcurrent/undercurrent detection (175–225 mV thresholds), integrates UVLO (30–38 V), and provides hardware FAULT interrupt (INTB) with per-port register status. Gate drive for external N-MOSFETs is generated from the 48-V bus, eliminating need for isolated HV supplies.

Key Specifications

Pinout & Package

TPS2383APMRG4 is housed in a 64-pin LQFP (PM) package with exposed thermal pad. Pin functions are validated per TI SLUS565F datasheet, including dedicated analog/digital grounds (AG1, AG2, DG, RG), eight port pairs (1P–8P, 1N–8N), gate drive outputs (1G–8G), sense inputs (1RS–8RS), and I²C/LED/control signals.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PoE PSE management applications.

Compared with TPS2383APMRG4, TPS2384PWR reduces external component count at the expense of isolation and LED control flexibility, while MAX5980GTJ+ extends power capability to PoE+ but omits legacy load compatibility-making TPS2383APMRG4 optimal for cost-sensitive, UL/IEC950-compliant 802.3af mid-spans requiring robust legacy interoperability.

Availability

TPS2383APMRG4 is available at Aetrix Electronics and suitable for PoE mid-span injectors, enterprise Ethernet switches, network video surveillance hubs, and IoT edge gateways requiring stable component supply and long-term lifecycle support.

Supply support for TPS2383APMRG4 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 over 50 years of innovation in power management and industrial interfaces.

The TPS2383A/B product line was engineered specifically for IEEE 802.3af-compliant Power Sourcing Equipment, targeting high-density, thermally efficient, and safety-certifiable PoE infrastructure in enterprise and industrial networking.

FAQ

What is the primary function of the TPS2383APMRG4 in a PoE system?

The TPS2383APMRG4 serves as a Power Sourcing Equipment Power Manager (PSEPM) IC that discovers, classifies, and safely delivers power to IEEE 802.3af-compliant Powered Devices over Ethernet cabling. It manages up to eight ports using external N-channel MOSFETs, performs real-time current/voltage monitoring via integrated 12-bit A/D, and enforces fault protection including UVLO, overvoltage, and overcurrent detection-all coordinated through an I²C slave interface. The TPS2383APMRG4 is central to ensuring safe, standards-compliant, and intelligent PoE power delivery.

Does the TPS2383APMRG4 support legacy (non-802.3af) device detection?

Yes, the TPS2383APMRG4 supports capacitive detection mode for identifying legacy devices that lack the 25-kΩ discovery signature. In this mode, the device's integrated A/D converter measures the load's capacitive value rather than resistance, enabling safe probing without risking damage to non-compliant equipment. This feature is enabled via register configuration and operates independently of the standard two-point resistor discovery method used for IEEE 802.3af PDs. The TPS2383APMRG4 thus provides backward compatibility while maintaining full compliance with the standard.

How does the TPS2383APMRG4 achieve EMI reduction during power-up?

The TPS2383APMRG4 reduces EMI through controlled di/dt ramp-up and ramp-down of port current using its integrated linear current amplifier and external CR timing capacitor. During power-up, it ramps current from zero to a maximum of 425 mA at a defined slew rate, avoiding abrupt transients. The CR pin generates a 1.5-V triangular waveform that shapes the gate drive profile for external N-MOSFETs. This controlled transition-combined with optional PTC fusing and careful PCB layout referencing RG-meets stringent EMC requirements for enterprise networking equipment. The TPS2383APMRG4's design inherently minimizes conducted and radiated emissions during PoE handshaking.

Can the TPS2383APMRG4 operate with isolated microcontrollers?

Yes, the TPS2383APMRG4 supports system-level ground isolation via its opto-coupler compatible SDA_O pin (Pin 57), which is a high-voltage open-drain output capable of directly driving opto-LEDs from the 48-V bus. When paired with SCL_I and SDA_I (3.3-V logic inputs), this allows full I²C communication across an isolation barrier without external level shifters or isolated DC/DC converters. The TPS2383APMRG4's dual-ground architecture (AG1, AG2, DG, RG) further enhances noise immunity in isolated topologies. This makes the TPS2383APMRG4 ideal for safety-critical PoE applications requiring SELV compliance.

What are the key thermal and packaging specifications for the TPS2383APMRG4?

The TPS2383APMRG4 is packaged in a 64-pin LQFP (PM) with exposed thermal pad, rated for −40°C to 85°C ambient operation. Its thermal characteristics include θ_JA = 65°C/W and θ_JC = 9°C/W, supporting up to 1.5 W power dissipation at 25°C with 15.4 mW/°C derating above that temperature. The device employs internal power-on-reset (POR) with dual timeout stages (8 CLKs for I²C, 65536 CLKs for full state machine) and low quiescent current (3–5 mA in off-mode). These features ensure reliable thermal performance in densely packed PoE switch or injector designs. The TPS2383APMRG4's thermal design enables stable operation without forced air cooling in typical 1U chassis environments.