Texas Instruments TPS2375PWRG4

Overview

TPS2375PWRG4 from Texas Instruments is an IEEE 802.3af-compliant powered device (PD) controller IC for Power over Ethernet applications, integrating a 0.58-Ω 100-V low-side MOSFET switch, fixed 450-mA operational current limit, 30.5 V/39.3 V UVLO thresholds, and open-drain power-good (PG) reporting. It operates in industrial temperature range (–40°C to 85°C) and supports Class 3 PD implementations in VoIP phones and security cameras.

For engineers reviewing the TPS2375PWRG4 datasheet, TPS2375PWRG4 pinout, TPS2375PWRG4 application, or TPS2375PWRG4 equivalent, key selection considerations include its fixed UVLO thresholds aligned with IEEE 802.3af, programmable inrush current via ILIM pin, classification resistor interface on CLASS pin, and TSSOP-8 package compatibility with PoE front-end designs requiring polarity-insensitive diode bridge inputs.

Technical Context

The TPS2375PWRG4 implements full IEEE 802.3af detection (1.4–10.1 V), classification (13–21 V), and operation states using internal comparators with hysteresis, including dedicated DET, CLASS, and UVLO comparators. Its functional block includes a current-limit amplifier, thermal shutdown circuitry, and a latched PG comparator referenced to RTN voltage.

It uses external resistors to configure critical functions: R(DET) = 24.9 kΩ sets detection signature, R(CLASS) = 255 Ω–4420 Ω selects IEEE Class 0–4, and R(ILIM) = 62.5 kΩ–500 kΩ programs inrush current (100–180 mA typical). The integrated 100-V MOSFET enables direct connection to PoE input diode bridges without external pass devices.

Key Specifications

Pinout & Package

TSSOP-8 package (PW suffix), 3.0 mm × 4.4 mm, 0.65 mm pitch, exposed thermal pad (not electrically connected).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar powered device controller applications.

Compared with TPS2375D and TPS2376PW, the TPS2375PWRG4 offers optimal balance of compact TSSOP-8 footprint, fixed IEEE-aligned UVLO, and proven thermal performance in volume PoE endpoint designs - making it the default choice for new 802.3af-compliant implementations.

Availability

TPS2375PWRG4 is available at Aetrix Electronics and suitable for VoIP phones, WLAN access points, security cameras, and POS terminals requiring stable component supply across production lifecycles and global manufacturing sites.

Supply support for TPS2375PWRG4 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 TPS2375 family was designed specifically for IEEE 802.3af Power over Ethernet powered devices, targeting cost-sensitive, high-reliability endpoints where integration, compliance assurance, and thermal robustness are critical.

FAQ

What is the primary function of the TPS2375PWRG4 in a PoE system?

The TPS2375PWRG4 serves as the IEEE 802.3af-compliant powered device (PD) controller, managing detection, classification, undervoltage lockout, inrush current limiting, and power-good signaling. It integrates a 100-V low-side MOSFET switch to deliver regulated power to downstream DC/DC converters. The TPS2375PWRG4 ensures safe, standards-compliant power extraction from Ethernet cables without requiring external microcontrollers or complex firmware.

Does the TPS2375PWRG4 support programmable UVLO thresholds?

No, the TPS2375PWRG4 features fixed UVLO thresholds of 30.5 V (falling) and 39.3 V (rising), optimized for full compliance with IEEE 802.3af. Unlike the TPS2376PW, it does not include a UVLO pin or adjustable threshold capability. This fixed configuration ensures predictable startup behavior with certified PSEs and eliminates resistor-divider design overhead. The TPS2375PWRG4 is intended for standard-compliant deployments where PSE output voltage stability is assured.

How is inrush current controlled on the TPS2375PWRG4?

Inrush current is programmed via an external resistor (R_ILIM) connected between the ILIM pin (Pin 1) and VSS. Using the recommended 178 kΩ ±1% resistor yields a typical inrush limit of 130 mA. The TPS2375PWRG4 supports R_ILIM values from 62.5 kΩ to 500 kΩ, enabling inrush currents from 100 mA to 180 mA. This feature prevents input voltage sag during bulk capacitor charging and ensures compatibility with legacy PSEs that cannot sustain high peak currents.

What is the role of the NC pin on the TPS2375PWRG4?

Pin 7 on the TPS2375PWRG4 is designated NC (No Connection) and is not internally bonded. It must remain unconnected in PCB layout - neither routed nor terminated. This differs from the TPS2376PW, which uses Pin 7 as the UVLO input. The NC designation ensures mechanical and thermal compatibility across the TPS2375/76/77 family while preserving pinout consistency for drop-in replacement in fixed-UVLO designs. Leaving Pin 7 floating has no electrical impact on TPS2375PWRG4 operation.

Can the TPS2375PWRG4 be used with both Mode A and Mode B PoE power sourcing?

Yes, the TPS2375PWRG4 supports both Mode A (power on data pairs) and Mode B (power on spare pairs) because it interfaces with the PoE input via a diode bridge - not directly to Ethernet PHY signals. Its VDD and VSS pins accept rectified DC from either configuration, and the internal architecture is polarity-insensitive. The 100-V rating and detection/classification circuitry operate identically regardless of PSE implementation, making the TPS2375PWRG4 fully agnostic to Mode A/Mode B selection at the system level.