M5291P/FP
Application Circuits
1. Step-up Circuit
V
IN
= 5 V
V
OUT
= 12 V
I
O
= 20 mA
f = 50 kHz
1
Q
S
R
2
Oscillator
D
3
C
T
820 pF
4
1.17 V
Comparator
+
−
L
510
µH
8
R
3
240
Ω
7
R
SC
3
Ω
6
+
C
IN
100
µF
V
IN
5V
5
V
OUT
12 V/20 mA
+
C
OUT
100
µF
R
1
9.1 kΩ
R
2
1 kΩ
2. Step-up Circuit with Transistor
L
10
µH
V
IN
= 5 V
V
OUT
= 12 V
I
O
= 1 A
f = 50 kHz
1
8
Q
S
R
R
3
1 kΩ
7
Oscillator
R
SC
60 mΩ
6
NPN
Tr
R
4
D
680
Ω
C
T
820 pF
2
3
1.17 V
Comparator
+
−
+
C
IN
100
µF
V
IN
5V
4
5
V
OUT
12 V/1 A
+
C
OUT
100
µF
R
1
9.1 kΩ
R
2
1 kΩ
REJ03D0841-0300 Rev.3.00 Jun 15, 2007
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