OB2578T
DESCRIPTION
OB2578T is an excellent primary side regulation power switch with CC/CV operation for medium level power AC/DC charger and adapter applications. The device operates in CCM/QR mode to provide high efficiency along with several functions of built-in protections. It removes the need for secondary feedback circuitry to lower the total bill of material cost. Proprietary Constant Voltage (CV) and Constant Current (CC) control is integrated as shown in the figure below. In CV control, the controller changes the mode of operation according to line voltage and load condition. At full loading, the controller operates in fixed frequency CCM in low line voltage and quasi-resonant (QR) mode in high line voltage. The primary side regulation power supplies up to high power without the efficiency limitation of DCM or audible noise. In CC control, OB2578T samples the primary-side average current and the demagnetization pulse to regulation the output current. The current and output power...
