TIDA-010034 Reference Design

Texas Instruments

IEEE802.3at Type-1 PoE and 12V adapter input to point of load reference design for IP network camera

Description

Power over Ethernet (PoE) enables power to be delivered over the same ethernet cable as data with no danger of cross-talk: interference: or corruption of the data streams. This reference design showcases end-to-end power tree for an IP network camera powered using PoE or 12-V adapter based on the TI’s DaVinci™ Digital Media Processor or different application processor. The power tree also derives rails required for different peripherals of an IP network camera like: Image sensor: motor control: Ethernet PHY: RS485 interface: IR LED illumination: audio: motion sensing and the alarm interface.

Features
  • TPS23755 IEEE802.3at PoE PD with no-opto flyback DC-DC controllerComplete IEEE802.3at PD solution for type-1 PoEIntegrated flyback controller with primary side regulation (PSR): frequency dithering and advanced startup12-V output: 89% efficiency of the PoE-powered flyback power stageSecondary side adapter priority control with smooth transitionNo diode ORing: 88% less power dissipation in adapter input path with TPS2121 power MUX for secondary side ORingTwo power tree implementations:For high efficiency: 12-V to PoL: using mid input range buck convertersFor low cost: 12-V to 5-V to PoL: using low input range buck convertersBoth power trees use buck converters with FPWM mode enabling:Fast transient response for handling dynamic load switching on rails suppling power to MPU core and DDR RAMLow output voltage ripple on voltage rails with tighter tolerances like MPU core and DDR RAM
Applications
Product Categories