TPS23758RJJT - 802.3at PoE PD with Flyback Controller | TI

IP Network Cameras

IP cameras are the flagship application for integrated PoE PD front ends because camera housings impose severe height and area limits. The TPS23758RJJT fits by combining the 802.3at PD interface, a 150-V internal FET, and the flyback controller in one 24-VSON (6x4 mm) exposed-pad package, eliminating a discrete high-voltage MOSFET and the optocoupler from the isolated supply. Primary-side regulation delivers an isolated 5 V or 3.3 V rail for the image sensor and ISP without secondary feedback components, while spread spectrum frequency dithering (SSFD) reduces switching harmonics that could couple into analog video paths. The 13 W Type 1 power class covers typical fixed and PTZ-lite camera loads. Designers should follow the TPS23758EVM-080 transformer recommendations to hold PSR output regulation within camera tolerance limits.

IEEE 802.11 Wireless Access Points

Wireless access points powered over Ethernet benefit directly from the TPS23758RJJT's integration level: one 24-VSON package provides PD classification, inrush limiting, the 150-V switching FET, and a current-mode no-opto flyback converter, freeing PCB area for RF front ends and reduced board layers. The advanced startup circuit supports startup directly from the PoE input voltage, simplifying brown-out behavior on long cable runs where the input voltage sags. PSR removes the optocoupler, improving reliability in ceiling-mounted equipment where service access is costly. SSFD eases conducted EMI compliance alongside the radio. Note that designs drawing above the 13 W Type 1 budget (e.g., multi-radio 802.11ax APs) require a higher-class PD device instead; the TPS23758 targets single-radio or lite configurations.

VoIP and IP Telephones

IP phones are classic 802.3at Type 1 (13 W) powered devices, and the TPS23758RJJT maps cleanly onto their power architecture: the integrated PD interface handles detection, classification, and 802.3at inrush compliance, while the internal 150-V FET and PSR flyback controller generate the isolated 5 V handset/DSLIC rail and downstream LDO inputs in a compact 24-VSON (6x4 mm) footprint. Eliminating the optocoupler via primary-side regulation reduces component count in cost-sensitive phone BOMs and removes an aging-sensitive part. The no-opto architecture also improves transient response consistency across production. Layout should keep the primary switching loop tight to limit radiated emissions near the handset audio path, per the TI datasheet layout section.

Size-Constrained PoE Powered Devices

Per the TI product description, the high integration level along with PSR, SSFD, and advanced startup makes the TPS23758 an ideal solution for size-constrained applications in general: security sensors, building-automation endpoints, thin access-control readers, and ceiling or wall-plate electronics where every cubic millimeter counts. The single 24-VSON (6x4 mm) package replaces a PD controller, an external high-voltage MOSFET, an optocoupler, and secondary feedback circuitry, cutting both board area and assembly cost. The 150-V FET rating provides margin against PoE input transients, and spread spectrum dithering reduces the size of EMI filtering needed. Engineers porting an EVM-080-based design should re-verify transformer parameters against their exact output voltage and current requirements to preserve PSR regulation accuracy.

Industrial PoE Sensor Nodes

Industrial Ethernet sensor and IoT nodes increasingly draw power from the same cable that carries data, and the TPS23758RJJT provides a robust front end for these Type 1 (13 W) nodes. The integrated 150-V power FET withstands the voltage transients common in factory cabling, while advanced startup ensures reliable power-up from the PoE input under worst-case cable conditions. Primary-side regulation keeps the isolated output free of optocoupler drift over the industrial temperature span, an advantage for long-life sensor installations. SSFD reduces conducted emissions, easing system-level EMI qualification in electrically noisy plants. The compact 24-VSON (6x4 mm) exposed-pad package provides a low thermal-resistance path to the PCB copper, supporting dissipative loads without a heatsink in most node designs.

PoE-Enabled Security and Access-Control Devices

Access-control panels, door controllers, and security sensors powered via PoE require an isolated, compliant power front end in a small footprint - exactly the TPS23758RJJT's design center. The device performs the IEEE 802.3at detection and classification handshake required by managed PoE switches, then its integrated 150-V FET and PSR flyback controller deliver an isolated logic rail without an optocoupler, improving mean time between failures for security infrastructure that must stay online. The no-opto scheme also removes a component sensitive to dust and temperature, valuable in uncontrolled environments. Type 1 (13 W) power capability covers most reader and controller loads; lock-solenoid bursts should be buffered with local bulk capacitance downstream of the flyback output, sized per the datasheet's output capacitance guidance.