R7731 Datasheet Text
R7731
Burst Triple Mode PWM Flyback Controller
General Description
The R7731 is a high performance, low cost, low start-up current, current mode PWM controller with burst triple mode to support green mode power saving operation. The R7731 integrates functions of Soft-Start, Under Voltage Lockout (UVLO), Leading Edge Blanking (LEB), Over Temperature Protection (OTP), internal slope pensation. It provides the users a superior AC/DC power application of higher efficiency, low external ponent counts and lower cost solution.
To protect the external power MOSFET from being damaged by supply over voltage, the R7731 output driver is clamped at 12V. Furthermore, R7731 Features fruitful protections like OLP (Over Load Protection) ,OVP (Over Voltage Protection) to eliminate the external protection circuits and provide reliable operation. R7731 is available in SOT-23-6 and DIP-8 packages.
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
Features z Very Low Start-Up Current (<30μA) z 10/14V UVLO z Soft-Start Function z Current Mode Control z Jittering Switching Frequency z Internal Leading Edge Blanking z Built-in Slope pensation z Burst Triple Mode PWM for Green-Mode z Cycle-by-Cycle Current Limiting z Feedback Open Protection z Output Over Voltage Protection z Over Temperature Protection z Over Load Protection z Soft Driving for Reducing EMI z High Noise Immunity z Opto Coupler Short Protection z RoHS pliant and Halogen Free
AC Mains (90V to 265V)
VO+ VO-
RT VDD
R7731
P
GATE
GND
CS
DS7731-03 March 2011
.richtek. 1
R7731
Ordering Information
R7731
Package Type E : SOT-23-6 N : DIP-8
Lead Plating System G : Green (Halogen...