MIC2145
Inductor
The MIC2145 has a programmable peak current to allow the
usage of small surface mount inductors. A 10µH or 4.7µH
inductor is recommended for most portable applications such
as powering white LEDs and biasing LCD panels. The
Micrel
inductor should have a saturation current rating higher than
the peak current during circuit operation. A low ESR (Equiva-
lent Series Resistance) inductor is also desirable for high
efficiency. Below are tables that list the maximum output
current at minimum input voltage with efficiencies greater
than 80%.
V
IN(min)
(V)
V
IN(max)
(V)
4.5
9.5
RSET
(
Ω
)
I
OUT(max)
(mA)
80
25
V
OUT
(V)
5
10
12
15
5
10
12
15
5
10
12
15
10
12
15
V
IN(min)
(V)
V
IN(max)
(V)
4.5
9.5
RSET
(
Ω
)
I
OUT(max)
(mA)
160
100
V
OUT
(V)
5
10
12
15
5
10
12
15
5
10
12
15
10
12
15
2.4
11.5
14.5
4.5
9.5
3.0
11.5
14.5
4.5
9.5
3.6
11.5
14.5
9.5
5.0
11.5
14.5
10k
20
15
150
50
10k
40
30
25 0
70
10k
50
40
190
10k
130
90
2.4
11.5
14.5
4.5
9.5
3.0
11.5
14.5
4.5
9.5
3.6
11.5
14.5
9.5
5.0
11.5
14.5
10k
90
70
250
150
10k
120
100
350
170
10k
150
120
300
10k
250
200
Table 1. Typical Application for 10
µ
H Inductor in
Basic Configuration
Table 2. Typical Application for 10
µ
H Inductor in
Bootstrap Configuration
V
IN(min)
(V)
V
IN(max)
(V)
4.5
9.5
RSET
(
Ω
)
I
OUT(max)
(mA)
250
80
V
OUT
(V)
5
10
V
IN(min)
(V)
V
IN(max)
(V)
4.5
4.5
RSET
(
Ω
)
I
OUT(max)
(mA)
500
225
V
OUT
(V)
5
10
12
15
3.0
9.5
9.5
400
60
50
12
15
3.0
4.5
4.5
200
150
130
Table 3. Typical Application for 4.7
µ
H Inductor in
Basic Configuration
Table 4. Typical Application for 4.7
µ
H Inductor in
Bootstrap Configuration
MIC2145
10
May 2003
MICREL [ MICREL SEMICONDUCTOR ]
