L6563 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

L6563

Advanced transition-mode PFC controller

STMicroelectronics 

L6563 - L6563A

Application information

to set the output voltage at the desired values use the following design procedure:

1. Determine the input RMS voltage Vinclamp that produces Vo = Vox:

Equation 6

Vinclamp

=

-V----o----x----–-----V----o---1-

Vo2 – Vo1

⋅

Vi

n2

–

-V----o----x----–-----V----o---2-

Vo2 – Vo1

⋅

Vin1

and choose a value Vinx such that Vin2 = Vinx < Vinclamp. This will result in a limitation of the

output voltage range below Vox (it will equal Vox if one chooses Vinx = Vinclamp)

2. Determine the divider ratio of the MULT pin (pin 3) bias:

Equation 7

k = ------------3--------------

2 ⋅ Vinx

and check that at minimum mains voltage Vin1 the peak voltage on pin 3 is greater than

0.65V.

3. Determine R1, the upper resistor of the output divider:

Equation 8

R1

=

∆----V-----o-

20

⋅

106

4. Calculate the lower resistor R2 of the output divider and the adjustment resistor RT:

Equation 9

R2 = 2.5 ⋅

R1 ⋅

-------------------------------------V-----i--n---2----–-----V----i--n---1--------------------------------------

(Vo1 – 2.5) ⋅ Vin2 – (Vo2 – 2.5) ⋅ Vin1

RT =

2⋅

k⋅

R1 ⋅

V-----i--n---2----–-----V----i--n---1-

Vo2 – Vo1

23/37

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