OB2287

OB2287 High Performance Current Mode PWM Controller GENERAL DESCRIPTION OB2287 is a highly integrated current mode PWM controller for medium to large power offline flyback converter applications. OB2287 enhances On-Bright’s PWM controller series by offering the Brownout Detection and Protection (BOP). OB2287 offers comprehensive protection coverage including Cycle-by-Cycle current limiting, internal Power-On Soft Start, VDD Under Voltage Lockout (UVLO), VDD Over Voltage Protection(OVP), VDD Clamp, Gate Clamp, Over Load Protection(OLP), Over Temperature Protection (OTP), Brownout Protection (BOP). OB2287 also features protections against pin open and short on selected pins. On-Bright’s proprietary OCP compensation can compensate CCM and DCM mode difference when used in universal AC input applications. Moreover, an internal 1-second restart timer prevents permanent OLP latch when the supply of the controller is provided by other DC sources. In applications where supply is self biased by auxiliary winding, this restart timer will not be triggered. To achieve good EMI performance, On-Bright’s proprietary built-in frequency shuffling is provided, together with soft switching control at the totem pole gate drive output. To meet the increasing stringent standby power requirements, in light or No load, OB2287 operates in On-Bright’s proprietary “Extended Burst Mode” without audible noise. OB2287 is offered in SOP-8 and DIP-8 packages. FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ TYPICAL A...