PowerZero^TM Multi-Mode Flyback Controller

The RT7789D series is an enhanced high-efficiency multi-mode PWM flyback controller, incorporating Richtek's proprietary PowerZero^TM and SmartJitter^TM technology. The innovative PowerZero^TM technology, featuring an integrated HV device, provides an excellent green power solution, while the SmartJitter^TM technology can reduce EMI emissions of a switch-mode power supply in green mode as well as eliminate output ripple due to frequency jittering. Also, the RT7789D series features a multi-mode control scheme, operating from continuous-conduction mode (CCM) to discontinuous-conduction mode (DCM) with valley switching, to achieve high efficiency and optimal performance. The RT7789D is a current-mode PWM controller for flyback converters. It integrates comprehensive and programmable protection features, which include brown-in/brown-out protection, VDD over-voltage protection (VDD OVP), output over-voltage and under-voltage protection (Output OVP and UVP), secondary rectifier short-circuit protection (SRSP), and external over-temperature protection (External OTP). For constant output power regulation, a resistor connected to CS pin can be used to achieve accurate line compensation across the universal input voltage range. With the above features, the RT7789D enables a cost-effective and compact design for a wide range of AC-DC conversion applications. It is available in a SOP-8 package.