DocID025723 Rev 4

11/29

ST1S50

Functional description

29

Equation 3

where:

Equation 4

subharmonic oscillations at a duty cycle over 50%.

Equation 5

where:

Equation 6

and

Equation 7

The resistor to adjust the output voltage gives the term from the output voltage to the FB pin.



p

1



--------------------------------------

–

 0.5

–





---------------------------------------------

+

=

1

------

+

=



=

–

L



=



















1

1

s





-------------------

s

2



n

2

------

++

-------------------------------------------

=

1

 m

C

1D

–

 0.5

–







----------------------------------------------------------

=



n

 f

SW



=



+

--------------------

=