MIC2570_07 Datasheet, PDF (10/15 Pages) Micrel Semiconductor – Two-Cell Switching Regulator

MIC2570
C1
2.0V to 3.1V 100µF
2 Cells
10V
L1
47µH
U1
8
IN
SW ¹
MIC2570
FB ⁶
SYNC GND
7
2
MBRA140
4.3V
3 _IN
U2
OUT ⁴
D1
2
MIC5203
EN
R2
374k
1%
C2
220µF
GND
1
10V
R1
20k
1%
V_OUT = 0.22V × (1+R2/R1)
V_{O U T}
3.3V/80mA
C3
1µF
16V
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
Example 6. Low-Noise 3.3V/80mA Regulator
C1
2.0V to 3.1V 100µF
2 Cells
16V
L1
47µH
U1
8
IN
SW ¹
MIC2570
5V ⁴
SYNC GND
7
2
D2
MBRA140
MBRA140
D1
C3
220µF
10V
+ V_{O U T}
5V/50mA
– I_OUT≤ +I_OUT
C2
220µF
10V
U1 Micrel
C1 AVX
C2 AVX
C3 AVX
C4 AVX
D1 Motorola
D2 Motorola
D3 Motorola
L1 Coilcraft
MIC2570-1BM
TPSD107M010R0100
TPSE227M010R0100
TPSE227M010R0100
TPSE227M010R0100
MBRA140T3
MBRA140T3
Tantalum, ESR = 0.1Ω
Tantalum, ESR = 0.1Ω
Tantalum, ESR = 0.1Ω
Tantalum, ESR = 0.1Ω
D3
MBRA140
C4
220µF
10V
– V_OUT
–4.5V to –5V/50mA
MBRA140T3
DO3316P-473, DCR = 1.2Ω
Example 7. ±5V/50mA Regulator
2.0V to 3.1V
2 Cells
C1
100µF
10V
L1
47µH
U1
8
IN
SW ¹
MIC2570
FB ⁶
SYNC GND
7
2
D1
MBRA140
D3
1N4148
C1
22µF
35V
R2
549k
1%
R1
4.99k
1%
C3
0.1µF
D2
–V_OUT = –0.22V × (1+R2/R1) + 0.6V MBRA140
R3
220k
C2
22µF
35V _–VOUT
U1 Micrel MIC2570-2BM
–24V/20mA
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
Example 8. –24V/20mA Regulator
Micrel, Inc.
MIC2570
10
August 2007