MIC4685
Micrel
Recommended Components for a Given Output Voltage (Bootstrap Configuration)
VOUT IOUT
*
R1
R2
VIN
C1
D1
D2
L1
C4
5.0V 2.1A 3.01k 976Ω
3.3V 2.2A 3.01k 1.78k
2.5V 2.0A 3.01k 2.94k
1.8V 2.0A 3.01k 6.49k
7.5V–16V 47µF, 20V
3A, 30V 1A, 20V
39µH
330µF, 6.3V
Vishay-Dale
Vishay-Dale
595D476X0020D2T
Schottky Schottky Sumida
B330A
MBRX120 CDRH127R-390MC 594D337X06R3D2T
6.0V–16V 47µF, 20V
3A, 30V 1A, 20V
Schottky Schottky Sumida
B330A
39µH
330µF, 6.3V
Vishay-Dale
Vishay-Dale
595D476X0020D2T
MBRX120 CDRH127R-390MC 594D337X06R3D2T
5.0V–16V 47µF, 20V
3A, 30V 1A, 20V
Schottky Schottky Sumida
B330A
39µH
330µF, 6.3V
Vishay-Dale
Vishay-Dale
595D476X0020D2T
MBRX120 CDRH127R-390MC 594D337X06R3D2T
5.0V–16V 47µF, 20V
3A, 30V 1A, 20V
Schottky Schottky Sumida
B330A
39µH
330µF, 6.3V
Vishay-Dale
Vishay-Dale
595D476X0020D2T
MBRX120 CDRH127R-390MC 594D337X06R3D2T
*
Maximum output current at minimum input voltage. See SOA curves for maximum output current vs. input voltage.
Table 1. Recommended Components for Common Ouput Voltages
D2
MBRX120
1A/20V
JP3
L1
39µH
J1
J2
U1 MIC4685BR
VIN
VOUT
2
5
6
IN
SW
C3
0.33µF
50V
1
3
C2
0.1µF
50V
BS
FB
C4*
optional
R1
R2
C1
ON
47µF
20V
J3
GND
EN
C5
330µF
6.3V
C7
0.1µF
50V
OFF
D1
GND
4, Tab
B330A
or
SS33
J4
GND
* C4 can be used to provide additional stability
and improved transient response.
Note: optimized for 5VOUT
Figure 3. Schematic Diagram
MIC4685
12
September 2002
MICREL [ MICREL SEMICONDUCTOR ]
