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 2006 Semtech Corp.

www.semtech.com

SC2620

POWER MANAGEMENT

Typical Application Circuits

R3

60.4k

SC2620

GND

SS2

PVIN

SW1

FB2

ROSC

COMP2

C9

47pF

11.3k

BOOST1

C1

22

µF

BOOST2

SW2

L1

22

µH

C2

0.1

µF

L2

10

µH

C4

0.1

µF

SS1

PGOOD1

COMP1

FB1

C3

D1

UPS140

D2

UPS140

R9

82.5k

OUT1

5V/2A

11.5k

R4

15.0k

R2

R1

5.76k

C7

0.1

µF

C10

0.1

µF

2.2nF

R5

R7

12.4k

C5

C8

2.7nF

D4

1N4148

L1 : Coiltronic DR74

OUT2

1.5V/2A

D3

1N4148

12-30V

L2 : Coiltronic DR73

47

µF

C6

68pF

C1 : Murata GRM21BR60J226M

C3 : Murata GRM31CR60J 476M

10

R10

C15

10

µF

VIN

C12

47pF

C11

47pF

C16

0.1

µF

C15: Murata GRM32DF51H106Z

Efficiency

40

45

50

55

60

65

70

75

80

85

90

0

0.5

1

1.5

2

Load Current (A)

Efficiency

40

45

50

55

60

65

70

75

80

85

90

00.5

11.5

2

Load Current (A)

Figure 18(a). 350kHz 12V-30V Input to 5V and 1.5V Step-down Converter. Notice that Channel 2 is bootstrapped

from OUT1. Channel 2 will be held off if OUT1 voltage is below 90% of its set value.

2

µs/div

CH1 : SW1 Voltage, 10V/div

CH2 : SW2 Voltage, 10V/div

Figure 18(b). Switching Waveforms. I

CH1

CH2