Texas Instruments TPS2375PW-1G4

Overview

TPS2375PW-1G4 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 enables PoE-powered VoIP phones, WLAN access points, and security cameras by managing detection, classification, inrush control, and fault protection.

For engineers reviewing the TPS2375PW-1G4 datasheet, TPS2375PW-1G4 pinout, TPS2375PW-1G4 application, or TPS2375PW-1G4 equivalent, key selection criteria include its fixed UVLO thresholds aligned with IEEE 802.3af, 8-pin TSSOP package, 15-kV system-level ESD rating, programmable inrush via ILIM pin, and compatibility with silicon rectifier-based front ends.

Technical Context

The TPS2375PW-1G4 implements a dedicated detection-comparator stage that draws ≤12 µA sleep current and generates a 24.9-kΩ incremental resistance signature using the DET pin. Its classification circuit sources precise currents (38.0–41.2 mA at R(CLASS) = 255 Ω) between 13 V and 21 V to signal Class 4 power level per IEEE 802.3af.

UVLO operation uses fixed thresholds (30.5 V falling, 39.3 V rising) with 8.8-V hysteresis to ensure stable turn-on/turn-off across cable voltage drop; the integrated 0.58-Ω pass device supports up to 350 mA continuous RTN current while providing thermal shutdown at 135°C with 20°C hysteresis.

Key Specifications

Pinout & Package

TPS2375PW-1G4 is housed in an 8-pin TSSOP (PW-8) package with exposed thermal pad, rated for 251 mW power dissipation at TA = 85°C (θJA = 159°C/W).

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 TPS2375PW-1G4 offers optimal balance of surface-mount compatibility, fixed-standard UVLO assurance, and thermal performance in space-constrained PoE endpoints-making it ideal for volume-manufactured VoIP and WLAN devices where IEEE compliance and layout density are primary constraints.

Availability

TPS2375PW-1G4 is available at Aetrix Electronics and suitable for VoIP phones, WLAN access points, security cameras, and POS terminals requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for TPS2375PW-1G4 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 and embedded processing technologies, with decades of expertise in power management and connectivity solutions.

The TPS2375 family was designed specifically for IEEE 802.3af Power over Ethernet powered devices, targeting cost-sensitive, high-reliability endpoints such as IP phones and wireless infrastructure equipment.

FAQ

What is the function of the ILIM pin on the TPS2375PW-1G4?

The ILIM pin on the TPS2375PW-1G4 is an input that sets the inrush current limit during power-up by connecting an external resistor to VSS. Using a 178-kΩ resistor configures the TPS2375PW-1G4 for 100–180 mA inrush, ensuring compatibility with legacy PSEs while preventing input voltage sag. The TPS2375PW-1G4 datasheet specifies valid resistor range as 62.5 kΩ to 500 kΩ; leaving ILIM open or shorted to VSS will cause malfunction.

Does the TPS2375PW-1G4 support IEEE 802.3at (PoE+) or 802.3bt?

No, the TPS2375PW-1G4 is strictly compliant with IEEE 802.3af (Type 1 PoE) and does not support 802.3at (PoE+) or 802.3bt (PoE++). It delivers up to 12.95 W at the PD input and implements only the Class 0–4 detection and classification protocol defined in 802.3af. For higher-power applications, TI's TPS2372-4 or TPS23861 would be required-neither of which are pin-compatible with the TPS2375PW-1G4.

How does the PG pin on the TPS2375PW-1G4 behave during startup?

The PG pin on the TPS2375PW-1G4 is an open-drain output that remains pulled low (via internal transistor to RTN) until RTN voltage exceeds 10.0 V and inrush current falls below 85% of its peak value. Once both conditions are met, PG transitions to high-impedance, signaling valid power delivery to downstream circuitry. A minimum 4-V differential between VDD and RTN is required for reliable PG assertion, as specified in the TPS2375PW-1G4 datasheet.

Can the TPS2375PW-1G4 be used with a center-tapped transformer front end?

No-the TPS2375PW-1G4 requires a diode-bridge front end (not center-tapped transformer) to achieve polarity-insensitive operation per IEEE 802.3af. Its DET and CLASS circuits rely on specific voltage windows (1.4–11.3 V for detection, 13–21 V for classification) established across a full-wave bridge. A center-tapped configuration violates the required common-mode referencing and disables proper signature generation; the TPS2375PW-1G4 datasheet explicitly assumes silicon rectifier bridge topology.

What is the maximum continuous current the TPS2375PW-1G4 can deliver through its RTN pin?

The TPS2375PW-1G4 supports a maximum continuous RTN current of 350 mA, as defined by its absolute maximum rating and SOA-limited operation at V(RTN) ≤ 80 V. While the current limit circuit triggers at 450 mA (405–515 mA range), sustained operation above 350 mA risks thermal shutdown or reliability degradation. This 350-mA limit directly enables Class 3 (6.49–12.95 W) and Class 4 (reserved, up to ~12.95 W) operation when paired with appropriate downstream DC/DC conversion, per the TPS2375PW-1G4 specification table.