ISL9444

FN7665 Rev 3.00

Page 7 of 25

May 29, 2012

Typical Application - ISL9444

SGND

15

PGND

29

9

RT

118k

30

+

EN3

+19V

UGATE2

PHASE2

ISL9444

+

CIN2

R6

C8

37

32

36

7

LGATE2

19

ISEN2

R5

C4

BOOT2

VIN

31

29

R7

38

FB1

UGATE1

PHASE1

+

C6

LGATE1

ISEN1

R4

C3

BOOT1

R1

OCSET3

VCC_5V

4

40

35

34

33

5

L2

17

Q2

VOUT2

R2

Q5

FB2

VOUT1

R13

+5.0V, 18A

CIN5

CIN7

L1

C2

+ 12.0V, 15A

150µF

200k

2.2µH

2.2µH

RJK0329DPB

1.74k

10.7k

3.92k

2.0k

3.24k

52.3k

0.22µF

10µF

4.7µF

180µF

10µF

0.22µF

330µF

UGATE3

PHASE3

+

R9

C10

25

LGATE3

ISEN3

R8

C9

BOOT3

24

R10

27

27

26

L3

20

Q7

FB3

VOUT3

+3.3V, 15A

1.5µH

3.09k

11.5k

3.92k

330µF

CIN9

10µF

+16V

8

OCSET1

R11

200k

16

OCSET2

R12

200k

11

1

PGOOD2

PFO

18

21

22

PGOOD1

+

C5

330µF

+C7

180µF

C1

0.1µF

22pF

CFF3

TK/SS2

TK/SS3

CIN3

150µF

+

CIN4

10µF

CFF1

4700pF

CFF2

1000pF

RJK0332DPB

Q3

Q4

RJK0332DPB

Q6

RJK0329DPB

RJK0332DPB

CIN6

10µF

EXTBIAS

RJK0329DPB

CIN8

10µF

0.22µF

Q1

+ C11

330µF

+

CIN1

150µF

PGOOD2

VOUT1

V

RPG

100k

3

EXTBIAS

C10

0.1µF

PFO

47nF

2 PFI

14

EN2

+16V

V

R14

64.9k

R15

10k

47nF

10

PGOOD1

PGOOD1

6

EN/SS1

47nF

PGOOD2

PGOOD

PGOOD3

12

MODE/SYNC

23

13

PG3_DLY

CLKOUT

R16

200

R3

200

VOUT1 can be connected to EXTBIAS for lower IC power dissipation and IC self-bias.

External boot diode may be added for PWM2.

Care must be taken to ensure VIN does not drop below EXTBIAS.