An energy efficient charger for tablets
The populated circuit boards in this reference design occupy just a 1 x 1 x 0.9-in. cube and are shown here next to couple other reference designs to give viewers a feel for relative size.This circuit uses the UCC28710 flyback controller in a quasi-resonant flyback to generate an isolated 5 V at up to 2 A. This design is over 80% efficient while charging a device. The design consumes less than 20 mW when plugged into an outlet with no device attached to the USB port. The UCC28710 implements primary-side regulation, eliminating the need for an opto-coupler and reducing the size and cost of the design.
