85-265VACin: 5V/1.5A AC/DC USB Charger with Auto-Detect based on PSR Flyback with BJT Switch
This reference design provides an isolated 5V/1.5A output from a universal 85-265VAC input with an efficiency greater than 78%. Employing the UCC28722 Primary Side Regulation (PSR) Flyback controller which helps to eliminate the opto-coupler and secondary side regulation components: this design delivers additional cost savings by employing a bipolar power switch. Additionally: the design features the TPS2511 USB Dedicated Charging Port Controller and Current Limiting Power Switch to safely charge most smart phones and tablets. The energy saving features of the UCC28722 allow this design to consume less than 50mW when plugged into the wall with no device attached to the USB port.
Greater than 78% efficiency at full load (5V/1.5A) Less than 50mW of stand-by power consumption under no load Constant Current regulation feature of UCC28722 ensures output short-circuit protection Auto detect feature of TPS2511 monitors USB Data line enabling charging of compliant USB devices Programmable current limiting function of TPS2511 delivers additional layer of protection Fast Start-up