Transition-Mode PFC and Quasi-Resonant Current Mode PWM Controller
The LD7798BG/IG/OG features transition mode power factor correction (PFC) controller with THDi optimizer and Quasi-Resonant (QR) current mode controller for high power application.
With intelligent PFC switching ON / OFF, zero current detection (ZCD) without aux-winding and frequency limitation mechanism to achieve better performance.
The IC also integrateds several functions, such as brown-in/out protection, over load protection (OLP), over temperature protection (OTP), PFC bulk over voltage protection (PFCOVP) output over voltage protection (FBAUXOVP), over current protection (OCP) with high / low line compensation and a latch pin for customized control.
Therefore it can protect the system from damage due to occasional failure.
The IC is available in SMD. LD7798BG/IG/OG GS in SOP-16 package.
FEATURES
▲ Integrated PFC boost and QR flyback controller
▲ Voltage mode transition operation for PFC
▲ Current mode quasi-resonant operation for flyback
▲ 180V max. input voltage rating for wide range output voltage applications
▲ Smart stabilization system and high efficiency for USB-PD application
▲ Brown in/out protection and RFI X-capacitor discharge function
▲ Internal soft-start function and PFC on/off control
▲ OVP (Over Voltage Protection)
▲ OCP (Cycle by Cycle Current Limit)
▲ Internal OTP function and external latch protection
▲ 550/-1000mA PFC Gate/Source sink capability
▲ 350/-1000mA Flyback Gate/Source sink capability
APPLICATIONS
▲ Power delivery (PD) application
▲ Power adaptor
Datasheet 
