SC1103

© 2000 SEMTECH CORP.

652 MITCHELL ROAD NEWBURY PARK CA

VOLTAGE MODE PWM CONTROLLER

PRELIMINARY - February 29, 2000

7

Fig. 9: 5V to 2.5V @ 4A with “flying capacitor” boost voltage.

TYPICAL APPLICATIONS (cont.)

Q1

Si4420DY

R4

2.7

R2

1k

D1

MBRD340

R1

10

L1

6.8uH

C7

1500/6.3V

C2

1500/6.3V

C4

0.1

R7

124

R6

124

C1

0.1

C5

0.01

+2.5V

+5V

GND

C8

0.1

R5

0.012

GND

VCC

1

Cs(-)

2

Cs(+)

3

PGND

4

DH

5

BST

6

FB

7

GND

8

U1

SC1103

C3

0.1

D2

LL42

C6

0.1

Fig. 10: 12V to 3.3V @ 10A with “flying capacitor” boost voltage.

Q1

IRL3103S

R4

2.7

R2

1k

D1

MBRB1530CT

R1

10

L1

5.6uH

C9

1500/6.3

C10

1500/6.3

C11

1500/6.3V

C3

820/16V

C2

820/16V

C4

820/16V

C6

0.1

R7

124

R6

205

C1

0.1

C7

0.01

Vout(+)

+12V

GND

C8

0.1

C12

0.1

R5

0.01

R3

1k

Vout(-)

VCC

1

Cs(-)

2

Cs(+)

3

PGND

4

DH

5

BST

6

FB

7

GND

8

U1

SC1103

C5

1.0

D2

LL42

3.3V