11

 2002 Semtech Corp.

www.semtech.com

POWER MANAGEMENT

SC1544

PRELIMINARY

GND

3.3V DUAL MEM

/SLP_S5

5V DUAL

Q4

IRLR3103

USB

C11

1uF

GND

PWR_OK

5VSB

C 9

0.01uF

1.8V

C3

100uF/6.3V

Q5

IRLR3103

U 1

SC1544-3.3

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

G5

3.3VDM

G6

G7

AGP

TYPEDET

PWR_OK

EN

/S3

/S5

USB

P C I

-CAP

+CAP

FC

5VSB

5VD

G1

G2/3

GND

3.3VD

G4

1.8V

G8

Q3

IRLR3103

C6

100uF/6.3V

GND

C8

100uF/6.3V

TYPEDET

EN

C7

100uF/6.3V

Q2

IRLR3103

3.3V

GND

GND

C4

100uF/6.3V

Q6

IRLR3103

C10

0.1uF

C1

100uF/6.3V

AGP

C5

100uF/6.3V

Q8

IRLR3103

/SLP_S3

Q7

IRLR3103

3.3V DUAL

C2

100uF/6.3V

5V

PCI

GND

GND

GND

Q1

IRLR3103

Notes:

(1) 3.3V option shown - see below for Q5 configuration for 2.5V option.

(2) 1.8V output shown powered from 3.3V. If powered from 5VSB, this becomes 1.8VSB.

(3) See Applications Information.

C2

100uF/6.3V

Q5

5VSB

GND

D1

GND

C6

100uF/6.3V

2.5V DUAL MEM

Q6

Q5 body diode in series with D1 to pre-charge 2.5V Dual Memory

D1 to ensure that the linear regulator will still regulate

3.3V

GND

C3

100uF/6.3V

U 1

SC1544-2.5

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

G5

2.5VDM

G6

G7

AGP

TYPEDET

PWR_OK

EN

/S3

/S5

USB

P C I

-CAP

+CAP

FC

5VSB

5VD

G1

G2/3

GND

3.3VD

G4

1.8V

G8

Typical Applications Circuits