Datasheet ON Semiconductor FL7921R — 数据表

DATA SHEET
www.onsemi.com Integrated Critical-Mode
PFC and Quasi-Resonant
Current-Mode PWM
Lightning Controller SOIC−16, 150 mils
CASE 751BG−01 FL7921R
Description The highly integrated FL7921R combines a Power Factor
Correction (PFC) controller and a Quasi−Resonant PWM controller.
Integration provides cost effect design and allows for fewer external
components.
For PFC, FL7921R uses a controlled on−time technique to provide a
regulated DC output voltage and to perform natural power factor
correction. An innovative THD optimizer reduces input current
distortion at zero−crossing duration to improve THD performance. The
PFC function is always on regardless of the PWM stage load condition
to ensure that high PF can be achieved at light load condition.
For PWM, FL7921R provides several functions to enhance power
system performance: valley detection, green−mode operation, high /
low line over−power compensation. Protection functions include
secondary−side open−loop and over−current with auto−recovery
protection, external recovery triggering, adjustable over−temperature
protection through the RT pin and external NTC resistor, internal
over−temperature shutdown, VDD pin OVP, DET pin over−voltage …