HVLED807PF

Device description

Doc ID 023464 Rev 5

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Ultimately, this will result in a low-frequency intermittent operation (hiccup-mode operation),

with very low stress on the power circuit. This special condition is illustrated in the timing

diagram of

Figure 21.

Figure 21.

Hiccup-mode OCP: timing diagram

4.11

High Power Factor implementation

Referring to the principle application schematic on

Figure 1, two contributions are added on

is intended for a single range input voltage. For wide range application a different reference

schematic can be used; refer to the dedicated application note for further details.

pin: as a consequence the input current is proportional to the input voltage during the line

period, implementing a high power factor correction. The contribution proportional to the

input voltage is generated using the auxiliary winding, as a consequence a diode in series to

Through the ROS resistor a positive contribution proportional to the average value of the

input voltage is added on the CS pin in order to keep a good line-regulation.

The voltage contribution proportional to the average value of the input voltage is generated

The R1 resistor between CS and SOURCE pin is needed to add on the CS pin also the

AM13571v1

Secondary diode is shorted here

t

t

t

1 V

Two switching cycles