MIC2570 Micrel, Inc.
MIC2570 10 August 2007
GND
FB
S W
MIC2570
S Y NC
U1 Micrel MIC2570-2BM
U2 Micrel MIC5203-3.3BM4
C1 AVX TPSD107M010R0100 Tantalum ESR = 0.1Ω
C2 AVX TPSE227M010R0100 Tantalum ESR = 0.1Ω
C3 Sprague 293D105X0016A2W Tantalum
D1 Motorola MBRA140T3
L1 Coilcraft DO3316P-473 DCR = 0.12Ω
7
6
1
2
8
IN
C1
100µF
10V
D1
L1
47µH
2.0V to 3.1V
2 Cells
V
OUT
= 0.22V × (1+R2/R1)
U1
MBRA140
C2
220µF
10V
MIC5203
IN
EN
GND
OUT
V
OUT
3.3V/80mA
C3
1µF
16V
1
2
3
4
R1
20k
1%
R2
374k
1%
U2
4.3V
Example 6. Low-Noise 3.3V/80mA Regulator
GND
5V
S W
MIC2570
S Y NC
U1 Micrel MIC2570-1BM
C1 AVX TPSD107M010R0100 Tantalum, ESR = 0.1Ω
C2 AVX TPSE227M010R0100 Tantalum, ESR = 0.1Ω
C3 AVX TPSE227M010R0100 Tantalum, ESR = 0.1Ω
C4 AVX TPSE227M010R0100 Tantalum, ESR = 0.1Ω
D1 Motorola MBRA140T3
D2 Motorola MBRA140T3
D3 Motorola MBRA140T3
L1 Coilcraft DO3316P-473, DCR = 1.2Ω
7
4
1
2
8
IN
C2
220µF
10V
+V
OUT
5V/50mA
2.0V to 3.1V
2 Cells
C1
100µF
16V
D1
MBRA140
L1
47µH
C3
220µF
10V
D2
MBRA140
D3
MBRA140
C4
220µF
10V
–V
OUT
–4.5V to –5V/50mA
– I
OUT
≤ +I
OUT
U1
Example 7. ±5V/50mA Regulator
GND
FB
S W
MIC2570
S Y NC
U1 Micrel MIC2570-2BM
C1 AVX TPSD107M010R0100, Tantalum ESR = 0.1Ω
C2 AVX TPSE226M035R0300, Tantalum ESR = 0.3Ω
C3 AVX TPSE226M035R0300, Tantalum ESR = 0.3Ω
D1 Motorola MBRA140T3
D2 Motorola MBRA140T3
L1 Coilcraft DO3316P-473, DCR = 0.12Ω
7
6
1
2
8
IN
C3
0.1µF
C1
100µF
10V
D3
1N4148
L1
47µH
R2
549k
1%
R1
4.99k
1%
2.0V to 3.1V
2 Cells
R3
220k
C2
22µF
35V
–V
OUT
–24V/20mA
D2
MBRA140
D1
MBRA140
C1
22µF
35V
–V
OUT
= –0.22V × (1+R2/R1) + 0.6V
U1
Example 8. –24V/20mA Regulator
