mic4574 Micrel Semiconductor, mic4574 Datasheet - Page 6

• Manufacturer Part Number: mic4574
• Description: Mic4574 200khz Simple 0.5a Buck Regulator
• Manufacturer: Micrel Semiconductor

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