GENERAL DESCRIPTION
OB2211/OB2212 is an offline PWM Power switch for low power AC/DC charger and adaptor applications. It operates in primary-side sensing and regulation. Consequently, opto-coupler and TL431 could be eliminated from design. Proprietary Constant Voltage (CV) and Constant Current (CC) control is integrated as shown in the figure below. In CC control, the current and output power setting can be adjusted externally by the sense resistor Rs at CS pin. In CV control, multi-mode operations are utilized to achieve high performance and high efficiency. Device operates in fixed frequency mode at large load conditions, frequency reduction mode at light/medium load and ‘Extended burst mode’ at No/light load conditions. OB2211/OB2212 offers power on soft start control and complete protection coverage with auto-recovery features including Cycle-by-Cycle current limiting, VDD over-voltage clamp and UVLO, fail-safe protection for open loop fault condition. Excellent EMI performance is...
On-Bright
