M5291P/FP
5. Inverse Polarity Circuit
V
IN
= 5 V
V
OUT
=
−5
V
I
O
= 40 mA
f = 50 kHz
1
Q
L
2
260
µH
3
C
T
820 pF
D
V
OUT
−5
V/40 mA
4
1.17 V
Oscillator
S
R
7
R
SC
1.5
Ω
6
8
Comparator
+
−
+
C
IN
100
µF
V
IN
5V
5
+
C
OUT
100
µF
R
1
1 kΩ
R
2
3.3 kΩ
6. Inverse Polarity Circuit with Transistor
V
IN
= 5 V
V
OUT
=
−12
V
I
O
= 1 A
f = 50 kHz
PNP
Tr
R
3
100
Ω
1
R
4
24
Ω
20
µH
2
Oscillator
Q
S
R
L
7
R
SC
0.1
Ω
6
8
3
C
T
820 pF
D
4
1.17 V
Comparator
+
−
+
C
IN
100
µF
V
IN
5V
5
V
OUT
−12
V/1 A
+
C
OUT
220
µF
R
1
2.4 kΩ
R
2
22 kΩ
REJ03D0841-0300 Rev.3.00 Jun 15, 2007
Page 6 of 9