Texas Instruments TPS23734RMTR

Overview

TPS23734 from Texas Instruments is an IEEE 802.3bt Type 3 PoE powered device (PD) interface with integrated current-mode DC-DC controller for flyback and active clamp forward topologies, supporting up to 30 W input power, ±1.5% load regulation at 5 V (with sync FET), and robust 100 V/0.3 Ω hotswap MOSFET - deployed in security cameras requiring high-efficiency, low-noise, and dual-power-source operation.

For engineers reviewing the TPS23734 datasheet, TPS23734 pinout, TPS23734 application, or TPS23734 equivalent, this page delivers verified technical context on PoE classification (Class 1–4), primary-side regulation (PSR), automatic MPS behavior, soft-stop shutdown, and spread-spectrum dithering - all critical for PoE PD design validation and BOM optimization.

Technical Context

The TPS23734 integrates a compliant IEEE 802.3bt/at PoE PD front-end with a current-mode PWM controller optimized for CCM flyback and ACF configurations. It supports both primary-side regulation (PSR) via auxiliary winding feedback and secondary-side regulation, with slope compensation, blanking, and adjustable dead time (via DT pin).

Its PoE interface features auto-stretching Maintain Power Signature (MPS) that dynamically adjusts pulse amplitude/duration per PSE type (Type 1–4), plus programmable frequency dithering (DTHR pin) and advanced startup with hiccup-mode overload protection - enabling reliable cold-start under low-bias conditions while meeting IEEE timing requirements.

Key Specifications

Pinout & Package

The TPS23734 is housed in a thermally enhanced 45-pin VSON (RMT) package measuring 7.00 mm × 5.00 mm, with dual exposed thermal pads (PAD_G connected to RTN, PAD_S to VSS) for efficient heat dissipation in high-power PoE applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PoE PD controller applications.

Compared with TPS23731 and LT4295, the TPS23734 uniquely integrates ACF capability, PSR-enabling CP/PSRS pins, and dual gate drivers - making it the only option among the three that supports high-efficiency active clamp forward converters with minimal external components.

Availability

TPS23734 is available at Aetrix Electronics and suitable for video security cameras, enterprise wireless access points, and VoIP telephony systems requiring stable component supply, long-term lifecycle assurance, and full IEEE 802.3bt compliance.

Supply support for TPS23734 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 power management technologies, with decades of leadership in Power over Ethernet solutions.

The TPS23734 belongs to TI's PoE PD controller product line, engineered specifically for high-efficiency, multi-standard (802.3bt/at) powered devices that integrate DC-DC conversion - targeting space-constrained, thermally demanding endpoints like cameras and APs.

FAQ

What is the maximum input power supported by the TPS23734?

The TPS23734 supports up to 30 W of input power as a Type 3 PoE PD per IEEE 802.3bt, with robust 100 V hotswap FET and 0.3 Ω typical R_DS(on). Its DC-DC controller is optimized for continuous conduction mode flyback and active clamp forward topologies delivering regulated outputs within this power envelope. The TPS23734 does not support Type 4 (60 W) operation.

Does the TPS23734 support primary-side regulation (PSR) in flyback designs?

Yes, the TPS23734 fully supports PSR via dedicated pins CP and PSRS, enabling regulation using auxiliary winding feedback without optocoupler or TL431. When PSRS is left open and CP is connected to the auxiliary winding, the TPS23734 implements PSR with ±1.5% load regulation at 5 V - a key feature confirmed in the datasheet's functional description and electrical characteristics.

How does the automatic Maintain Power Signature (MPS) work on the TPS23734?

The TPS23734's automatic MPS adjusts pulsed current amplitude and duration based on detected PSE type (Type 1–4) and real-time load current, using EMPS pin control and internal auto-stretch logic. For Type 3–4 PSEs, it draws 16.25–21.5 mA total VSS current with 26.2–26.9% duty cycle - ensuring signature compliance while minimizing idle consumption without external configuration.

Can the TPS23734 operate with an external AC adapter in parallel with PoE?

Yes, the TPS23734 includes dedicated APD (auxiliary power detect) and APDO (auxiliary power detect output) pins to manage seamless switchover between PoE and external adapter. When APD rises >1.5 V above RTN, the internal hotswap FET turns off and classification halts - allowing the system to prioritize adapter power while maintaining TPS23734 supervision and DC-DC control.

What thermal considerations apply to the TPS23734's 45-pin VSON package?

With RθJC(bot_POE) = 3.9°C/W and RθJC(bot_DCDC) = 9.1°C/W, the TPS23734's dual-exposed-pad VSON (RMT) package requires separate copper fills: PAD_S tied to VSS for PoE path heat, PAD_G tied to RTN for DC-DC section heat. Layout must use large thermal vias and minimize trace resistance to achieve the specified 38.5°C/W junction-to-ambient rating.