LD7537

LD7537 12/15/2011 Green-Mode PWM Controller with Frequency Swapping and Integrated Protections Rev. 01a General Description The LD7537 is built-in with several functions, protection and EMI-improved solution in a tiny package. It takes less components counts or circuit space, especially ideal for those total solutions of low cost. The implemented functions include low startup current, green-mode compensation. power-saving operation, leading-edge blanking of the current sensing and internal slope It also features more protections like OLP (Over Load Protection) and OVP (Over Voltage Protection) to prevent circuit damage occurred under abnormal conditions. Furthermore, the Frequency Swapping function is to reduce the noise level and thus helps the power circuit designers to easily deal with the EMI filter design by spending minimum amount of component cost and developing time. Features z z z z z z z z z z z z High-Voltage CMOS Process with Excellent ESD protection Very Low Startup Current (<20μA) Current Mode Control Green Mode Control UVLO (Under Voltage Lockout) LEB (Leading-Edge Blanking) on CS Pin Internal Frequency Swapping Internal Slope Compensation OVP (Over Voltage Protection) on Vcc Pin Brownout Protection OLP (Over Load Protection) 300mA Driving Capability Applications z z Switching AC/DC Adaptor and Battery Charger Open Frame Switching Power Supply Typical Application AC input EMI Filter DC Output VCC BNO OUT LD7537 COMP GND CS photocoupler 1 Leadtrend Tec...