LED5000

Application notes - buck conversion

Doc ID 023951 Rev 1

15/51

Figure 7.

Transconductance embedded error amplifier

system stability but it can be useful to reduce the noise at the output of the error amplifier.

The transfer function of the error amplifier and its compensation network is:

Equation 8

Equation 9

Equation 10

whereas the zero is defined as:

Equation 11

AM13491v1

+

-

FB

COMP

dV

E/A

A

()

A

V0

1s

+

R

c

C

c

⋅⋅

()

⋅

s

2

R

0

C

0

C

p

+

() R

c

C

c

sR

0

C

c

⋅

R

0

C

0

C

p

+

() R

c

C

c

⋅

+

⋅

+

() 1

+

⋅

+

⋅⋅

⋅

⋅

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

=

f

P LF

1

2

π R

0

C

c

⋅⋅

⋅

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

=

f

P HF

1

2

π R

c

C

0

C

p

+

()

⋅⋅

⋅

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

=

F

Z

1

2

π R

c

C

c

⋅⋅

⋅

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

=