Application notes

LED2001

14/42

DocID024346 Rev 1

Figure 6. Transconductance embedded error amplifier

system stability but it is 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

+

-

FB

COMP

dV

E/A

AM12897v1

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

⋅⋅

⋅

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

=