Presentation on theme: "Low Standby Power AC Adapter L6562 + L6668 90W 19V/4.7A AC-DC Converter Reference Design."— Presentation transcript:
Low Standby Power AC Adapter L6562 + L6668 90W 19V/4.7A AC-DC Converter Reference Design
90W Adaptor General Features Input Voltage range: 100 to 240Vac Output Voltage and current: 19V/4.7A Power Factor Correction: Above 0.98 Low Standby < 0.4W at no load condition High Efficiency, typical 82% at low line full load Latched OVP
L6562 - Power Factor Correction Transition Mode Control Very Precise Adjustable Output Over Voltage Protection Ultra-Low Startup Current (<70 A) ON-CHIP Filter ON Current Sense Disable Function 1% internal reference voltage -600mA/+800mA Totem Pole Gate Driver
L6668 - PWM Controller Current Mode Controller with sophisticated standby feature On board high voltage startup Low quiescent current (<2mA) Slope Compensation Pulse-by-pulse & Hiccup-Mode OCP Interface with PFC Controller Disable Function (on/off control) Latched Disable for OVP/OTP Function Programmable soft start
L6668 – Standby Operation The device operates in different modes depending on the converter’s load condition 1.) Fixed Frequency at heavy load 2.) Frequency-foldback at medium load 3.) Burst Mode Control with no or very light load.
This MOSFET has to withstand high stress for short period. L6668 + L6562 Operation 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!