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 2004 Semtech Corp.

www.semtech.com

SC4605

POWER MANAGEMENT

Applications Information (Cont.)

Design Example 4: 5V to 3.3V @ 5A application with SC4605 and its typical efficiency characteristics.

Efficiency vs Load current

0.9

0.91

0.92

0.93

0.94

0.95

0.96

0.97

0.98

123

45

Load current (A)

Vin=5V

Vo=3.3V

R3

2.87k

C3

4.7u

C2 2.2n

C6

150u

R1

14.3k

C7

150u

R11

100

C1

220p

ON/OFF

C14

0.1u

VIN =5V

ON/OFF

R6

1.0

R5

1.0

J1

1

2

3

4

5

6

D2

ETQ P 6F2R 5

2.5u

C5

22u

C4

22u

C71

1u

M1

2 x S i7882

V O U T=3.3V /5A

M2

C12

22u

C9

10n

R8

97.6

R7

4.7k

R9

1.5k

C20

470pF

R10

100

J2

1

2

3

4

5

R12

100

GND

TRIM

U1

S C 4605

VCC

2

ISET

3

COMP

4

FSET

5

BST

1

DRVH

10

DRVL

8

VSENSE

6

GND

7

PHASE

9

C10

22u

R13

1

R3

2.87k

C3

4.7u

C2 2.2n

C6

150u

R1

14.3k

C7

150u

R11

100

C1

220p

ON/OFF

C14

0.1u

VIN =5V

ON/OFF

R6

1.0

R5

1.0

J1

1

2

3

4

5

6

D2

ETQ P 6F2R 5

2.5u

C5

22u

C4

22u

C71

1u

M1

2 x S i7882

V O U T=3.3V /5A

M2

C12

22u

C9

10n

R8

97.6

R7

4.7k

R9

1.5k

C20

470pF

R10

100

J2

1

2

3

4

5

R12

100

GND

TRIM

U1

S C 4605

VCC

2

ISET

3

COMP

4

FSET

5

BST

1

DRVH

10

DRVL

8

VSENSE

6

GND

7

PHASE

9

C10

22u

R13

1