DocID022998 Rev 4

11/35

ST1S31

Functional description

35

Equation 2

current sense circuitry (0.369

),

zero given by the ESR of the output capacitor.

the error amplifier that introduces a double pole at one half of the switching frequency.

Equation 3

Equation 4

where:

Equation 5

avoid sub-harmonic oscillations at duty cycle over 50%.

Equation 6

where:

Equation 7

and

Equation 8



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

1

1



L

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

–

 0.5

–







+

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

1

s



z

------

+





1

s



p

------

+











=



Z

1



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

=



p

1



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

–

 0.5

–





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

+

=

1

------

+

=



=

–

L



=



















1

1

s





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

s

2



n

2

------

++

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

=

1

 m

C

1D

–

 0.5

–







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

=



n

 f

SW



=