6

FN6666.4

December 22, 2008

Typical Application Circuits

The typical application circuits generate the 5V/8A and 3.3V/8A (system regulator), or 1.05V/15A and 1.5V/15A (chip set) supplies

in a notebook computer. The input supply (VBAT) range is 5.5V to 25V.

FIGURE 1. TYPICAL SYSTEM REGULATOR APPLICATION CIRCUIT WITH INDUCTOR DCR CURRENT SENSE

FIGURE 2. TYPICAL SYSTEM REGULATOR APPLICATION CIRCUIT WITH RESISTOR SENSE

V BAT

VI N

PH A SE1

UG AT E 1

LG A T E 1

O C SET 1

ISEN 1

VO U T 1

FB 1

P HAS E 2

UG AT E 2

LG A T E 2

O C SET2

ISEN 2

VO U T 2

FB 2

3.3V

5V

LD O 3

PVC C

VC C

PVC C

P GOO D

PG N D

PA D

EN 1

EN 2

F SET1

F SET2

BO O T 1

BO O T 2

FC C M

LD O 3 E N

0.22µF

0.22µF

IRF7821

IRF7821

IRF7832

IRF7832

4.7µH

4.7µH

9.09k

68.1k

750

1200pF

14k

14k 0.022µF

100k

0.01µF

0.01µF

19.6k

24.3k

1µF

4.7µF

10k

45.3k

1µF

330µF

330µF

1200pF

750

14k

14k

0.022µF

4x10µF

ISL62391, ISL62392

VB A T

VIN

PH A S E1

UG AT E 1

LG A T E 1

OC S E T 1

IS E N 1

VO U T 1

FB 1

P HAS E 2

UG AT E2

LG A T E 2

OC S E T 2

ISEN 2

VO U T 2

FB 2

3.3V

5V

3.3 V

LD O 3

PV C C

VC C

PV C C

PG O O D

PG N D

GN D

EN 1

EN 2

FS E T 1

FS E T 2

BO O T 1

BO O T 2

FC C M

LD O 3 E N

0.22µF

0.22µF

IRF7821

IRF7821

IRF7832

IRF7832

4.7µH

4.7µH

4x10µF

ISL62391, ISL62392

0.01µF

0.01µF

24.3k

19.6k

1µF

1µF

4.7µF

9.09k

68.1k

1200pF

1200pF

750

750

100k

45.3k

10k

330µF

330µF

0.001

0.001

1k

1k

1k

1k

ISL62391, ISL62392