LED5000

Application notes - alternative topologies

Doc ID 023951 Rev 1

45/51

Equation 78

6.4.1

compensation network can be calculated as:

Equation 79

and

Table 10.

BB and boost parameters

Boost

Buck-boost

k

f

p

ω

p

2

π

⋅

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

1

2

π

⋅

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

K

D

C

O

R

LOAD

⋅

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

⋅

==

1

R

LOAD

V

OUT

I

LED

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

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

R

LOAD

1D

–

()

2

⋅

R

CS

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

1

K

m

---------

K

1D

–

()

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

+

⎝⎠

⎜⎟

⎛⎞

⋅

++

1

R

LOAD

D

⋅

V

OUT

I

LED

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

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

R

LOAD

1D

–

()

2

⋅

R

CS

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

1

K

m

---------

K

1D

–

()

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

+

⎝⎠

⎜⎟

⎛⎞

⋅

++

1

0.5

D

–

() R

CS

T

SW

L

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

V

OUT

V

IN

–

V

OUT

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

R

CS

T

SW

L

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

⋅⋅

+

⋅⋅

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

1

0.5

D

–

() R

CS

T

SW

L

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

V

OUT

V

IN

V

+

OUT

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

R

CS

T

SW

L

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

⋅⋅

+

⋅⋅

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

0.5

R

CS

T

SW

L

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

D1

D

–

()

⋅⋅

⋅

⋅

0.5

R

CS

T

SW

L

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

D1

D

–

()

⋅⋅

⋅

⋅

R

C

R

EA

A

0

----------

BW

f

p

---------

⋅

=