Presentation on theme: "Low Standby Power AC Adapter L L6668"— Presentation transcript:
1 Low Standby Power AC Adapter L6562 + L6668 90W 19V/4.7A AC-DC Converter Reference Design
2 90W Adaptor General Features Input Voltage range: 100 to 240VacOutput Voltage and current: 19V/4.7APower Factor Correction: Above 0.98Low Standby < 0.4W at no load conditionHigh Efficiency, typical 82% at low line full loadLatched OVP
3 L6562 - Power Factor Correction Transition Mode ControlVery Precise Adjustable Output Over Voltage ProtectionUltra-Low Startup Current (<70mA)ON-CHIP Filter ON Current SenseDisable Function1% internal reference voltage-600mA/+800mA Totem Pole Gate Driver
4 L PWM ControllerCurrent Mode Controller with sophisticated standby featureOn board high voltage startupLow quiescent current (<2mA)Slope CompensationPulse-by-pulse & Hiccup-Mode OCPInterface with PFC ControllerDisable Function (on/off control)Latched Disable for OVP/OTP FunctionProgrammable soft start
5 L6668 – Standby OperationThe device operates in different modes depending on the converter’s load condition1.) Fixed Frequency at heavy load2.) Frequency-foldback at medium load3.) Burst Mode Control with no or very light load.
6 L6668 + L6562 Operation This MOSFET has to withstand high stress for short period.Points to note:PWM is powered up before PFC.PFC is switched off during standby mode.PWM MOSFET has to withstand high stress for a short period of time under low line, full load before bulk capacitor voltage build up!