Texas Instruments TPS23757PWR

Overview

TPS23757PWR from Texas Instruments is a combined Power over Ethernet (PoE) powered device (PD) interface and current-mode DC/DC controller optimized for isolated flyback and active-clamp forward converters. It supports IEEE 802.3at Type 1 (13 W) PD operation, integrates a robust 100 V / 0.5 Ω hot-swap MOSFET, features dual complementary gate drivers with programmable dead time, and operates across –40°C to 125°C junction temperature. It enables PoE-powered video phones and security cameras with adapter ORing capability.

For engineers reviewing the TPS23757PWR datasheet, TPS23757PWR pinout, TPS23757PWR application, or TPS23757PWR equivalent, key selection considerations include its 253 kHz typical switching frequency, 78% maximum duty cycle, 9 V converter startup voltage, 465 mA PoE current limit, and support for external wall adapter priority via APD/PPD control logic.

Technical Context

The TPS23757PWR implements a dual-gate-drive architecture where GATE drives the primary MOSFET high-side and GAT2 drives synchronous rectifiers or secondary switches with configurable dead time (40–188 ns). Its current-mode PWM controller includes internal slope compensation (155 mV), programmable blanking (35–78 ns), and soft-start (1.9–6.2 ms).

Its PoE interface provides IEEE 802.3at-compliant detection (64.3 μA typical), classification (programmable via CLS resistor), and hot-swap control with UVLO (35 V rising threshold), foldback protection (12.3 V), and thermal shutdown (145°C turn-off). Adapter ORing is implemented through independent APD (adapter priority detect) and PPD (power present detect) inputs with defined voltage thresholds and hysteresis.

Key Specifications

Pinout & Package

TSSOP-20 package with exposed thermal pad; 0.65 mm pitch; JEDEC MO-153 compliant; RoHS lead-free.

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 TPS23754PWR, the TPS23757PWR adds GAT2 and APD for enhanced topology support and redundancy; versus LT4275AIMSE#PBF, it integrates full DC/DC control-reducing component count and layout area but limiting topology choice.

Availability

TPS23757PWR is available at Aetrix Electronics and suitable for IEEE 802.3at-compliant video telephones, IP security cameras, and wireless access points requiring stable component supply, long-term lifecycle support, and industrial temperature grade performance.

Supply support for TPS23757PWR 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 broad industrial, automotive, and communications reach.

The TPS23757PWR belongs to TI's Power over Ethernet product line, designed specifically to integrate IEEE-compliant PD interface functionality with high-efficiency isolated DC/DC control for space-constrained, thermally demanding endpoints.

FAQ

What is the primary function of the TPS23757PWR in a PoE-powered system?

The TPS23757PWR serves as an integrated Power over Ethernet powered device (PD) interface and current-mode DC/DC controller. It handles IEEE 802.3at Type 1 detection, classification, and hot-swap control while simultaneously driving isolated flyback or forward converters. In a deployed system, the TPS23757PWR manages power handoff between PoE and external adapters, regulates output rails, and protects against overcurrent and thermal faults - all within a single TSSOP-20 package.

How does the TPS23757PWR support adapter ORing functionality?

The TPS23757PWR supports adapter ORing through dedicated APD (adapter priority detect) and PPD (power present detect) pins. When V_APD exceeds 1.5 V, the internal hot-swap MOSFET opens, disabling PoE power draw and asserting APb to enable external adapter regulation. PPD >1.55 V independently enables the hot-swap switch and APb, allowing flexible power-source arbitration. This dual-input logic ensures seamless transition without brownouts - a core capability of the TPS23757PWR not found in earlier TI PD controllers.

What are the key thermal specifications of the TPS23757PWR and how do they impact board design?

The TPS23757PWR specifies a –40°C to 125°C junction temperature range and thermal shutdown at 145°C with 20°C hysteresis. Its TSSOP-20 package has θ_JA = 74°C/W (high-k board) and Ψ_JT = 0.45°C/W, indicating strong case-to-top thermal coupling. For reliable operation, designers must expose the thermal pad to a minimum 100 mm² copper pour with ≥4 thermal vias to inner ground planes. The TPS23757PWR's 0.43 Ω hot-swap R_DS(on) and 78% duty cycle also reduce self-heating under full 13 W load - critical for fanless IP camera and access point deployments.

Can the TPS23757PWR drive synchronous rectifiers, and if so, how is timing controlled?

Yes, the TPS23757PWR can drive synchronous rectifiers using its GAT2 output, which is complementary to GATE with user-programmable dead time. A resistor from DT to ARTN sets the delay between GATE turn-off and GAT2 turn-on (and GATE turn-on and GAT2 turn-off), preventing shoot-through. Typical dead times range from 40 ns (R_DT = 24.9 kΩ) to 188 ns (R_DT = 75 kΩ), measured with 1 nF load. This precise timing control - unique to the TPS23757PWR among TI's PoE controllers - enables high-efficiency synchronous rectification in flyback topologies without external timing ICs.

What is the role of the CS pin in the TPS23757PWR, and what design precautions apply?

The CS (current sense) pin in the TPS23757PWR is the primary current-mode control input, monitoring the high-side sense resistor (R_CS) to terminate GATE ON-time when the 0.55 V threshold is exceeded. It includes internal slope compensation (155 mV) and blanking (35–78 ns) to reject turn-on spikes. To maintain accuracy, PCB routing from R_CS to CS must be short and shielded from GATE/GAT2 noise; TI recommends placing R_CS adjacent to the MOSFET source and routing CS directly to the IC with guard traces. This attention to layout is essential for stable operation of the TPS23757PWR in high-noise PoE environments.