The TPS23755RJJT device combines a Power over Ethernet (PoE) powereddevice (PD) interface, a 150-V switching power FET, and a current-mode DC-DC controller optimizedfor flyback topology. The high level of integration along with primary side regulation (PSR),spread spectrum frequency dithering (SSFD), and advanced startup makes theTPS23755RJJT an ideal solution for size-constrained applications. The PoEimplementation supports the IEEE 802.3at standard as a 13-W, Type 1 PD.
The PSR feature of the DC-DC controller uses feedback from an auxiliary winding forcontrol of the output voltage, eliminating the need for external shunt regulator and optocoupler.It is optimized for operation with secondary side diode rectifier (typically12-V output or higher).Typically, the converter operates in continuous conduction mode (CCM)at a switching frequency of 250 kHz.
SFFD and slew rate control helps to minimize the size and cost of the EMI filter.Advanced Startup allows the use of minimal bias capacitor while simplifying converter startup andhiccup design.
Secondary auxiliary power detect capability provides priority for asecondary side power adapter, while ensuring smooth transition to and from PoE input power, with noefficiency or thermal trade-off.
The DC-DC controller features internal soft-start, slope compensation, and blanking. For non-isolatedapplications, the buck topology is also supported by the TPS23755.
Feature
- Complete IEEE 802.3at PD Solution for Type 1 PoE
- Ethernet Alliance (EA) Logo Certified Designs Available
- Robust 100-V, 0.36-Ω (typ) Hotswap MOSFET
- Programmable Classification Level
- Integrated PWM Controller with 0.77-Ω (typ) 150-V Power MOSFET
- Flyback Controller with PSR
- Supports CCM Operation with Secondary Side Diode Rectifier
- ±3% (typ, 12-V Output) Load Regulation (5%-100% range)
- Supports Low-side Switch Buck Topology
- Adjustable Switching Frequency with Synchronization
- Advanced Startup
- Programmable Slew Rate and Frequency Dithering for Enhanced EMI Reduction
- Flyback Controller with PSR
- Secondary Side Adapter Priority Control with Smooth Transition
- –40°C to 125°C Junction Temperature Range
- Small 6-mm x 4-mm VSON Package
