Texas Instruments TPS23750PWP

Overview

TPS23750PWP from Texas Instruments is an integrated IEEE 802.3af Power over Ethernet (PoE) Powered Device (PD) interface and primary-side DC/DC PWM controller in a TSSOP-20 PowerPAD™ package. It features a 100 V, 0.6 Ω internal pass MOSFET, fixed 140 mA inrush limit, standard UVLO thresholds (30.5 V / 39.3 V), and supports flyback, forward, and buck topologies for PoE-powered wireless access points and VoIP phones.

For engineers reviewing the TPS23750PWP datasheet, TPS23750PWP pinout, TPS23750PWP application, or TPS23750PWP equivalent, key selection considerations include PoE detection/classification compliance, programmable switching frequency (90–565 kHz), current-mode control with leading-edge blanking, 50% duty cycle limiting, and thermal shutdown at 140°C - all critical for robust industrial-grade PoE-PD front-end design.

Technical Context

The TPS23750PWP integrates dual functional domains: a full-featured PoE interface (detection, classification, UVLO, inrush control, 100 V pass switch) and a primary-side DC/DC controller with current-mode PWM, voltage-output error amplifier (1.50 V FB reference), and soft-start/hiccup fault management. Its architecture enables isolated and non-isolated topologies without requiring secondary-side feedback components.

It implements precise analog functions including SEN/SENP voltage-level translation (1.492 V typical regulation), programmable oscillator frequency via FREQ resistor (30–300 kΩ), and configurable current-sense blanking (BL pin selects 0/70/105 ns delay). The internal 5 V VBIAS regulator powers control circuitry and optocouplers, while AUX supplies 10 V gate drive with 12–28 mA current limit.

Key Specifications

Pinout & Package

TSSOP-20 PowerPAD™ package with exposed thermal pad internally connected to VSS; requires PCB thermal vias for junction temperature control per TI SLMA002 layout guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PoE-PD interface and DC/DC controller applications.

Compared with TPS23750PWP, TPS23770PWP provides identical performance with legacy UVLO for backward compatibility, while LT4275AIMSE#TRPBF extends capability to PoE+ with higher voltage tolerance and external MOSFET flexibility - making it suitable for next-generation high-power PD designs.

Availability

TPS23750PWP is available at Aetrix Electronics and suitable for wireless access points, VoIP phones, and security cameras requiring stable component supply, industrial temperature operation (–40°C to 85°C), and IEEE 802.3af compliance.

Supply support for TPS23750PWP 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 and embedded processing solutions for industrial, automotive, and communications markets.

The TPS23750PWP belongs to TI's Power over Ethernet product line, designed specifically to integrate PoE-PD interface and primary-side DC/DC control into a single IC for space-constrained, cost-sensitive networked devices.

FAQ

What is the maximum input voltage the TPS23750PWP can handle on its COM, SEN, and RTN pins?

The TPS23750PWP supports an input voltage range of –0.7 V to 100 V on COM, SEN, and RTN pins, enabling robust operation across the full PoE voltage envelope (up to 57 V nominal, with transients). This rating accommodates worst-case PoE line conditions including residual ripple and inductive spikes, ensuring reliable front-end operation without external clamping in most applications. The 100 V absolute maximum also covers surge events defined in IEEE 802.3af Clause 33.

How does the TPS23750PWP implement PoE classification for Class 4 devices?

The TPS23750PWP implements Class 4 classification by sinking 38.0–41.2 mA through the CLASS pin when a 255 Ω resistor is connected to VSS, per IEEE 802.3af Table 33–8. This current is drawn for up to 75 ms at ~10 V, allowing the PSE to identify the PD's power class. The TPS23750PWP's internal current source ensures accurate classification without external components, and the CLASS pin must never be shorted to ground to avoid malfunction.

Can the TPS23750PWP operate in a non-isolated buck topology, and what pins enable this?

Yes, the TPS23750PWP supports non-isolated buck topologies using the SEN/SENP voltage-level translator feature. When SEN is tied >1 V above RTN and SENP is connected to the output rail, the internal translator applies (SENP–SEN) ≈1.492 V to the FB pin via a 15 kΩ resistor. This enables direct high-side output sensing without optocouplers or level-shifters - simplifying feedback in buck converters while maintaining regulation accuracy within ±2% over temperature.

What is the purpose of the BL pin on the TPS23750PWP, and how does it affect current-sense timing?

The BL pin on the TPS23750PWP selects the current-sense blanking period to prevent false triggering of the current-limit comparator due to gate-drive and rectifier-recovery currents. With BL open, blanking is minimized (~40–90 ns); tying BL to RTN adds ~70 ns; tying BL to VBIAS adds ~105 ns. This configurability allows designers to match blanking duration precisely to their MOSFET and diode characteristics - critical for stable operation in fast-switching flyback or forward converters.

Does the TPS23750PWP include thermal protection, and how does it behave during fault conditions?

Yes, the TPS23750PWP includes thermal shutdown at 140°C with 17°C hysteresis. When junction temperature exceeds 140°C, the device disables the GATE driver and enters hiccup mode - cycling on/off until temperature falls below 123°C. This behavior protects both the IC and external MOSFET during sustained overload or inadequate heatsinking. The PowerPAD™ package and recommended thermal layout per TI SLMA002 are essential to maintain safe operating temperatures in continuous 12 W+ applications.