Texas Instruments TPS2376PWG4

Overview

TPS2376PWG4 from Texas Instruments is an IEEE 802.3af-compliant Powered Device (PD) controller IC for Power over Ethernet applications, integrating a 0.58-Ω low-side MOSFET switch, programmable UVLO via dedicated UVLO pin, 450-mA fixed operational current limit, and open-drain power-good (PG) output. It operates across –40°C to 85°C and supports Class 3 PD implementations in VoIP phones and security cameras.

For engineers reviewing the TPS2376PWG4 datasheet, TPS2376PWG4 pinout, TPS2376PWG4 application, or TPS2376PWG4 equivalent, key selection considerations include its adjustable UVLO threshold (1.93 V / 2.49 V), 100-V absolute maximum RTN voltage rating, 15-kV system-level ESD capability, and TSSOP-8 package compatibility with legacy PoE infrastructure.

Technical Context

The TPS2376PWG4 implements full IEEE 802.3af detection, classification, and inrush control using discrete external resistors on DET (24.9 kΩ), CLASS (255–4420 Ω), and ILIM (62.5–500 kΩ) pins. Its UVLO comparator connects directly to the UVLO pin-unlike TPS2375/TPS2377-enabling user-defined upper/lower thresholds via resistor divider.

It features a true open-drain PG output referenced to RTN (not VSS), thermal shutdown at 135°C with 20°C hysteresis, and a pass device with 0.58-Ω typical rDS(on) at 300 mA. The internal architecture includes independent detection and classification comparators with hysteresis, current mirror-based inrush regulation, and bias current mirroring to maintain accuracy across temperature.

Key Specifications

Pinout & Package

TSSOP-8 package (PW suffix), 3.0 mm × 4.4 mm, 0.65 mm lead 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 TPS2375PW and TPS2377PW, the TPS2376PWG4 uniquely provides field-programmable UVLO thresholds without sacrificing pin compatibility, enabling single-BOM support across diverse PSE generations while maintaining full IEEE 802.3af detection/classification compliance.

Availability

TPS2376PWG4 is available at Aetrix Electronics and suitable for VoIP phones, WLAN access points, security cameras, and POS terminals requiring stable component supply across extended product lifecycles and global manufacturing sites.

Supply support for TPS2376PWG4 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 delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, precision, and energy efficiency.

The TPS237x family is designed specifically for IEEE 802.3af Power over Ethernet Powered Devices, integrating detection, classification, inrush control, and power switching into compact 8-pin packages for cost-sensitive, space-constrained endpoint equipment.

FAQ

What is the function of the UVLO pin on the TPS2376PWG4?

The UVLO pin on the TPS2376PWG4 accepts an external resistor divider between VDD and VSS to set custom upper and lower undervoltage lockout thresholds (1.93 V / 2.49 V nominal). Unlike the TPS2375PW and TPS2377PW, this pin enables field-tunable startup behavior for compatibility with legacy PSEs that fall below IEEE 802.3af's 44-V minimum output specification. The TPS2376PWG4 uses this input exclusively-no internal connection exists on other family members.

How does the TPS2376PWG4 implement IEEE 802.3af detection and classification?

The TPS2376PWG4 implements detection by pulling the DET pin low through an external 24.9-kΩ resistor to generate a 25-kΩ incremental resistance signature for the PSE. During classification, it sources precise current (e.g., 39.4 mA for Class 4) from the CLASS pin through a 255-Ω resistor to signal power class. Both functions operate only within defined voltage windows (1.4–11.3 V for detection, 13–21 V for classification) to minimize power consumption and avoid false triggering.

What is the maximum continuous current the TPS2376PWG4 can deliver through its RTN pin?

The TPS2376PWG4 delivers up to 450 mA continuously through its RTN pin under normal operation, as specified in its absolute maximum ratings and electrical characteristics. This value reflects the fixed current limit enforced by the internal pass device and aligns with IEEE 802.3af's 350–400 mA PSE monitoring window. The device also supports higher peak inrush currents (e.g., 130 mA typical at 178 kΩ on ILIM) during startup, but transitions to the 450-mA steady-state limit once inrush completes.

Can the TPS2376PWG4 be used in Class 4 PD applications?

Yes, the TPS2376PWG4 supports Class 4 PD operation (6.49–12.95 W) using a 255-Ω classification resistor on the CLASS pin, which draws 39.4 mA nominal-within the IEEE 802.3af Class 4 current range of 36–44 mA. Its 0.58-Ω rDS(on), 100-V RTN rating, and thermal shutdown at 135°C ensure safe operation at the upper end of Class 4 power delivery. External components-including the DC/DC converter and bulk capacitance-must also be rated for sustained 12.95-W input.

Does the TPS2376PWG4 require an external pullup resistor on the PG pin?

Yes, the TPS2376PWG4 PG pin is an open-drain output referenced to RTN-not VSS-so it requires an external pullup resistor to a valid logic-high voltage (e.g., 3.3 V or 5 V) on the downstream side of the DC/DC converter. The datasheet specifies minimum 4-V differential between VDD and RTN for reliable PG assertion. Without the pullup, PG remains floating and cannot signal "power good" to system controllers or sequencers.