MIC4574

Micrel, Inc.

M9999-062105

6

June 2005

Applications Information

The applications circuits that follow have been constructed

and tested. Refer to “Application Note 15” for additional

information, including efficiency graphs and manufacturer’s

addresses and telephone numbers for most circuits.

C1

47µF

35V

D1

1N5819

C2

220µF

16V

L1

100µH

SGND

FB

SW

MIC4574-3.3BN

SHDN

6V to 24V

3.3V/0.5A

C1 Nichicon

UPL1V470MEH, ESR = 0.34Ω

C2 Nichicon

UPL1C221MPH, ESR = 0.16Ω

D1 Motorola

1N5819

L1

Sumida

RCH875-101K, DCR = 0.28Ω

PGND

24

1

7

3

5

Figure 1. 6V–24V to 3.3V/0.5A Buck Converter

Through Hole

C1

47µF

35V

D1

1N5819

C2

220µF

16V

L1

100µH

SGND

FB

SW

MIC4574-5.0BN

SHDN

8V to 24V

5.0V/0.5A

C1 Nichicon

UPL1J470MEH, ESR = 0.34Ω

C2 Nichicon

UPL1C221MPH, ESR = 0.16Ω

D1 Motorola

1N5819

L1

Sumida

RCH875-101K, DCR = 0.28Ω

PGND

24

1

7

3

5

Figure 2. 8V–24V to 5V/0.5A Buck Converter

Through Hole

C1

33µF

63V

MBR160

C2

220µF

16V

L1

220µH

SGND

FB

SW

MIC4574BN

SHDN

16V to 24V

12V/0.5A

R2

13.0k

1%

R1

1.50k

1%

C1 Nichicon

UPL1J330MEH, ESR = 0.35Ω

C2 Nichicon

UPL1C221MPH, ESR = 0.16Ω

D1 Motorola

MBR160

L1

Sumida

RCH106-221K, DCR = 0.78Ω

PGND

1

7

4

2

5

3

Figure 3. 16V–24V to 12V/0.5A Buck Converter

Through Hole

For a mathematical approach to component selection and

circuit design, refer to “Application Note 14.”