17

© 2006 Semtech Corp.

www.semtech.com

SC4524

POWER MANAGEMENT

Applications Information

POWER

STAGE

GMP = 8

Ω

REFERENCE

VOLTAGE

1V

+

-

R5

C5

C6

RO

R2

R1

FB

C11

ESR

C1

ROUT

VOUT

V

IN

I

OUT

-1

GMA =

280

µΩ

-1

COMP

V

1.6M

Ω

Figure 10. Simplified Control Loop Equivalent Circuit

Bode Plots of Control-to-Ouput, Output-to-Control and the Overall Loop

Gain. Control-to-output transfer function is shown with two poles near

half the switching frequency

ω

Figure 11.

2

p

ω

1

R

n

5

R

1

1

p

ω

3

p

ω

6

R

1

5

R

1

1

Z

ω

C

ω

ω

Gain

2

S

ω

OUT

G













+

2

1

2

O

MA

R

R

R

R

G













+

2

1

2

5

MA

R

R

R

R

G

n

R

C

OUT

1

C

ω

)

j

(

T

ω

OUT

COMP

v

v

Control-to-Output

Transfer Function