R7731 Burst Triple Mode PWM Flyback Controller General Description Features zz z zz Very Low Start-Up Current (<30A) The R7731 is a high performance, low cost, low start-up zz z zz 10/14V UVLO current, current mode PWM controller with burst triple zz z zz Soft-Start Function mode to support green mode power saving operation. The zz z zz Current Mode Control R7731 integrates functions of Soft-Start, Under Voltage zz z zz Jittering Switching Frequency Lockout (UVLO), Leading Edge Blanking (LEB), Over zz z zz Internal Leading Edge Blanking Temperature Protection (OTP), internal slope zz z zz Built-in Slope Compensation compensation. It provides the users a superior AC/DC zz z zz Burst Triple Mode PWM for Green-Mode power application of higher efficiency, low external zz z zz Cycle-by-Cycle Current Limiting component counts and lower cost solution. zz z zz Feedback Open Protection To protect the external power MOSFET from being zz z zz Output Over Voltage Protection damaged by supply over voltage, the R7731 output driver zz z zz Over Temperature Protection is clamped at 12V. Furthermore, R7731 features fruitful zz z zz Over Load Protection protections like OLP (Over Load Protection) ,OVP (Over zz z zz Soft Driving for Reducing EMI Voltage Protection) to eliminate the external protection zz z zz High Noise Immunity circuits and provide reliable operation. R7731 is available zz z zz Opto Coupler Short Protection in SOT-23-6 and DIP-8 packages. zz z zz RoHS Compliant and Halogen Free Applications z Adaptor and Battery Charger z ATX Standby Power z Set Top Boxes (STB) z DVD and CD(R) z TV/Monitor Standby Power z PC Peripherals Typical Application Circuit VO+ AC Mains (90V to 265V) VO- RT VDD R7731 COMP GATE GND CS DS7731-03 March 2011 www.richtek.com 1R7731 Ordering Information R7731 Package Type E : SOT-23-6 N : DIP-8 Lead Plating System G : Green (Halogen Free and Pb Free) Note : Richtek products are : RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. Marking Information For marking information, contact our sales representative directly or through a Richtek distributor located in your area. Pin Configurations (TOP VIEW) GATE VDD CS 6 5 4 23 GND COMP RT SOT-23-6 GND COMP NC RT 8 7 6 5 23 4 GATE VDD NC CS DIP-8 www.richtek.com DS7731-03 March 2011 2