
MAX828, MAX829
http://onsemi.com
16
+
5
4
2
3
1
OSC
MAX828: Capacitors = 10 F
MAX829: Capacitors = 3.3 F
+
+
V
in
+
+
+V
out
Figure 51. A Positive Doubler, with a Negative Inverter
V
out
All of the previously shown converter circuits have only single outputs. Applications requiring multiple outputs can be
constructed by incorporating combinations of the former circuits. The converter shown above combines Figures 24 and 36 to form
a negative output inverter with a positive output doubler. Different combinations of load regulation are shown below. In
Figures 52 and 53 the positive doubler has a constant I
out
= 15 mA while the negative inverter has the variable load. In Figures 54
and 55 the negative inverter has the constant I
out
= 15 mA and the positive doubler has the variable load.
I
out
, NEGATIVE INVERTER OUTPUT CURRENT (mA)
Figure 52. Negative Inverter Load Regulation,
Output Voltage vs. Output Current, MAX828
V
o
,
0
30
20
10
5.0
9.0
4.5
9.5
8.5
4.0
I
out
, NEGATIVE INVERTER OUTPUT CURRENT (mA)
Figure 53. Negative Inverter Load Regulation,
Output Voltage vs. Output Current, MAX829
V
o
,
Negative Inverter R
out
= 28
T
A
= 25
°
C
0
30
20
10
5.0
9.0
4.5
9.5
8.5
4.0
Positive Doubler
I
out
= 15 mA
Positive Doubler
I
out
= 15 mA
Negative Inverter
Negative Inverter
Negative Inverter R
out
= 28.8
T
A
= 25
°
C
I
out
, POSITIVE DOUBLER OUTPUT CURRENT (mA)
V
o
,
Figure 54. Positive Doubler Load Regulation,
Output Voltage vs. Output Current, MAX828
Positive Doubler
R
out
= 21.4
I
out
, POSITIVE DOUBLER OUTPUT CURRENT (mA)
V
o
,
Figure 55. Positive Doubler Load Regulation,
Output Voltage vs. Output Current, MAX829
0
30
20
10
5.0
9.0
4.5
9.5
8.5
4.0
0
30
20
10
5.0
9.0
4.5
9.5
8.5
4.0
T
A
= 25
°
C
Positive Doubler
R
out
= 20
Negative Inverter
Negative Inverter
T
A
= 25
°
C
Negative Inverter I
out
= 15 mA
Negative Inverter I
out
= 15 mA