MIC2570
C2
68µF, 35V
Micrel
L1
47µH
U1
2.0V to 3.1V
2 Cell
C1
330µF
16V
8
D1
1N5819
1
D2
1N5819
C3
68µF
35V
D3
1N5819
R2
2.2M
1%
V
OUT
50V/10mA
IN
SW
MIC2570
FB
SYNC GND
7
2
6
C4
82µF
63V
R1
10k
1%
1+R2/R1)
U1
C1
C2
C3
C4
D1
D2
D3
L1
Micrel
Sanyo
Sanyo
Sanyo
Sanyo
Motorola
Motorola
Motorola
Sumida
V
OUT
= 0.22
MIC2570-2BM
16MV330GX Electrolytic ESR = 0.1Ω
35MV68GX Electrolytic ESR = 0.22Ω
35MV68GX Electrolytic ESR = 0.22Ω
63MV826X
Electrolytic ESR = 0.34Ω
1N5819
1N5819
1N5819
RCH106-470k DCR = 0.16Ω
Example 9. Voltage Doubler
L1
U1
2.0V to 3.1V
2 Cell
C1
100µF
10V
47µH
8
D1
MBRA140
IN
SW
MIC2570
FB
SYNC GND
7
2
1
D2
LED
X5
I
LED
R1
11k
1%
6
C2
220µF
10V
U1
C1
C2
D1
L1
Micrel
AVX
AVX
Motorola
Coilcraft
I = 0.22V/R1
MIC2570-2BM
TPSD107M010R0100 Tantalum ESR = 0.1Ω
TPSE227M010R0100 Tantalum ESR = 0.1Ω
MBRA140T3
DO3316P-473 DCR = 0.12Ω
Example 10. Constant-Current LED Supply
L1
47µH
U1
2.0V to 3.1V
2 Cell
C1
100µF
10V
8
D1
V
OUT
5V/100mA
MBRA140
1
IN
SW
MIC2570
FB
SYNC GND
7
2
R2
434k
1%
6
C2
220µF
10V
D2
1N4148
R3
100k
74C04
R1
20k
1%
V
OUT
= 0.22V
(1+R2/R1)
Enable
Shutdown
U1
C1
C2
D1
L1
Micrel
AVX
AVX
Motorola
Coilcraft
MIC2570-2BM
TPSD107M010R0100 Tantalum ESR = 0.1Ω
TPSE227M010R0100 Tantalum ESR = 0.1Ω
MBRA140T3
DO3316P-473 DCR = 0.12Ω
Example 11. 5V/100mA Regulator with Shutdown
4-72
1997
MICREL [ MICREL SEMICONDUCTOR ]
