Description

AN4339

4/27

DocID025039 Rev 1

Figure 2. L6564 block diagram

Some of the important features of the L6564 device are shown below.

L6564 features



Fast “bidirectional” input voltage feed-forward (1/V2 correction)



Accurate adjustable output overvoltage protection



Protection against feedback loop disconnection (latched shutdown)



Inductor saturation protection



AC brownout detection



Low (

 100 A) start-up current



6 mA max. operating bias current





-600/+800 mA totem pole gate driver with active pull-down during UVLO



SSOP10 package

1.3

Description of power supply

The main feature of this converter is that the input current is almost in phase with the mains

voltage, therefore the power factor is close to unity and hence low current harmonics. This is

achieved by the L6564 TM PFC controller, which shapes the input current as a sine wave in

phase with the mains voltage. The power supply utilizes a typical flyback converter topology,

using a transformer to provide the required insulation between the primary and secondary

side. The converter is connected after the mains rectifier and the capacitor filter, which in

this case is quite small to avoid damage to the shape of the input current. The flyback switch

is represented by the Power MOSFET M1, and driven by the L6564 device.