SmartJitter^TM Multi-Mode Flyback Controller

The RT7740MA is an enhanced high-efficiency multi-mode PWM flyback controller, incorporating Richtek's proprietary SmartJitter^TM technology. The innovative SmartJitter^TM technology is used to reduce EMI emissions of a switch-mode power supply in green mode operation, and at the same time eliminate the output ripple due to frequency jittering. In operation, the RT7740MA features a multi-mode control scheme, operating from the continuous-conduction mode (CCM) to the discontinuous-conduction mode (DCM) with valley switching, so as to achieve high efficiency as well as the optimal performance. The RT7740MA operates as a current-mode PWM controller for flyback converters possessing comprehensive features, of which programmable protections consist of the propagation delay compensation, output over-voltage protection (OVP), external over-temperature protection (OTP), and bulk-capacitor brown-in/brown-out protection. With above features, the RT7740MA enables one to achieve a cost-effective and compact design for a wide-range AC-DC conversion applications. The RT7740MA is available in an SOT-23-6 package.