R7731AGE Richtek

R7731A Burst Triple Mode PWM Flyback Controller General Description Features zz z zz Very Low Start-up Current (<30A) The R7731A is a high-performance, low cost, low start-up zz z zz 10/14V UVLO current and 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 R7731A 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) and 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 Limit component counts and lower cost solution. zz z zz Feedback Open Protection To protect the external power MOSFET from being zz z zz Over Voltage Protection damaged by supply over voltage, the R7731A output driver zz z zz Over Temperature Protection is clamped at 12V. Furthermore, R7731A features fruitful zz z zz Over Load Protection protections like Over Load Protection (OLP) and Over zz z zz Soft Driving for Reducing EMI Voltage Protection (OVP) to eliminate the external zz z zz Driver Capability 200mA protection circuits and provide reliable operation. R7731A zz z zz High Noise Immunity is available in SOT-23-6 and DIP-8 packages. zz z zz Opto-Coupler Short Protection zz z zz RoHS Compliant and Halogen Free Ordering Information R7731A Package Type Applications E : SOT-23-6 N : DIP-8 z Adaptor and Battery Charger Lead Plating System z ATX Standby Power G : Green (Halogen Free and Pb Free) z Set-Top Box (STB) Note : z DVD and CD(R) Richtek products are : z TV/Monitor Standby Power RoHS compliant and compatible with the current require- z PC Peripherals ments of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. Marking Information R7731AGE IDP= : Product Code IDP=W W : Date Code R7731AGE R7731AGN : Product Number RichTek YMDNN : Date Code R7731A GNYMDNN R7731A-10 August 2011 www.richtek.com 1R7731A Pin Configurations (TOP VIEW) GND COMP NC RT 8 7 6 5 GATE VDD CS 6 5 4 23 23 4 GND RT COMP GATE VDD NC CS SOT-23-6 DIP-8 Typical Application Circuit VO+ AC Mains (90V to 265V) VO- RT VDD * R7731A COMP GATE GND CS * : See Application Information Functional Pin Description Pin No. Pin Name Pin Function SOT-23-6 DIP8 1 8 GND Ground. Comparator Input. By connecting an opto-coupler to this pin, the peak 2 7 COMP current set point is adjusted accordingly to the output power requirement. 3 5 RT Set the switching frequency by connecting a resistor to GND. 4 4 CS Primary Current Sense. 5 2 VDD IC Power Supply. 6 1 GATE Gate Driver Output to drive the external MOSFET. No Internal Connection. -- 3, 6 NC www.richtek.com R7731A-10 August 2011 2