MIC4574
Micrel, Inc.
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.
For a mathematical approach to component selection and
circuit design, refer to
“Application Note 14.”
L1
3
SHDN
SW
7
3.3V/0.5A
8V to 24V
3
SHDN
SW
7
L1
100µH
5.0V/0.5A
100µH
1
6V to 24V
C1
47µF
35V
5
MIC4574-3.3BN
V
IN
FB
SGND PGND
2
4
D1
1N5819
C2
220µF
16V
5
C1
47µF
35V
MIC4574-5.0BN
FB
V
IN
SGND PGND
2
4
1
D1
1N5819
C2
220µF
16V
C1
C2
D1
L1
Nichicon
Nichicon
Motorola
Sumida
UPL1V470MEH, ESR = 0.34Ω
UPL1C221MPH, ESR = 0.16Ω
1N5819
RCH875-101K, DCR = 0.28Ω
C1
C2
D1
L1
Nichicon
Nichicon
Motorola
Sumida
UPL1J470MEH, ESR = 0.34Ω
UPL1C221MPH, ESR = 0.16Ω
1N5819
RCH875-101K, DCR = 0.28Ω
Figure 1. 6V–24V to 3.3V/0.5A Buck Converter
Through Hole
Figure 2. 8V–24V to 5V/0.5A Buck Converter
Through Hole
3
SHDN
V
IN
SGND
2
SW
FB
PGND
4
7
L1
220µH
R2
13.0k
1%
R1
1.50k
1%
12V/0.5A
16V to 24V
C1
33µF
63V
5
MIC4574BN
1
MBR160
C2
220µF
16V
C1
C2
D1
L1
Nichicon
Nichicon
Motorola
Sumida
UPL1J330MEH, ESR = 0.35Ω
UPL1C221MPH, ESR = 0.16Ω
MBR160
RCH106-221K, DCR = 0.78Ω
Figure 3. 16V–24V to 12V/0.5A Buck Converter
Through Hole
M9999-062105
6
June 2005
MICREL [ MICREL SEMICONDUCTOR ]
