90W Single stage PFC-flyback u

90W Single stage PFC-flyback using L6562A for LED driver:In these years, power LEDs for lighting is quite hot application. For the reasons: their
life of LED is significantly longer at 100,000 to 15,000 full-power hours (11+ years) to
half brightness, the cost of power LEDs is rapidly coming down, and it’s easy to find
different sources from the market recently.
We are always using the words to talk about LED lighting: high efficiency (light out per
watt in), long life… but if we look back to the power supply solution for LED lighting, it’s
hard to find the benefit of the long life. The E-caps using in the switching mode power
supply solution are limiting the total solution’s lifetime. And for several tens watt
application, it’s hard to find suitable solution to meet the regulator requirement: Power
Factor or Harmonic Current requirement, but with low costing also.
In this file, introduces the solution without E-cap, using traditional TM PFC controllor
L6562A to control the flyback topology, combining the functions of PFC(Power Factor
correction) and flyback topology (AC-DC converter), to meet the requirements: Long
lifetime to match the LED Lighting’s feature, PF or Harmonic Current for regulator, and
also low costing for commerce. In this application, there are big advantages as talked
above, but also a little drawback maybe somebody don’t like: double line frequency ripple
voltage on output, and also cause the same frequency ripple current on LEDs. It’s possible
to decrease the value of ripple voltage by adding e-caps at output side as adaptors, but it’s
impossible to get the same small ripple voltage as adaptors do.