MAX1720 ON Semiconductor, MAX1720 Datasheet - Page 11

• Manufacturer Part Number: MAX1720
• Description: Switched Capacitor Voltage Inverter
• Manufacturer: ON Semiconductor

the converter’s output resistance and dramatically enhances the load regulation. For closed loop operation, the desired
regulated output voltage must be lower in magnitude than −V
the shutdown input voltage threshold is typically 0.5 V
to the converter’s input. This characteristic will not present a problem when used in applications with constant input voltage.
In this case the zener breakdown was measured at 25 mA. The performance characteristics for the above converter are shown
below. Note that the dashed curve sections represent the converter’s open loop performance.
A zener diode can be used with the shutdown input to provide closed loop regulation performance. This significantly reduces
−1.0
−2.0
−3.0
−4.0
−5.0
0
Figure 31. Load Regulation, Output Voltage vs.
T
A
= 25°C
10
A
I
out
, OUTPUT CURRENT (mA)
20
Output Current
V
in
Figure 32. Line and Load Regulated Negative Output Voltage
30
+
40
1
2
3
B
Capacitors = 10 mF
OSC
50
10 k
http://onsemi.com
in
MAX1720
and therefore, the regulated output voltage will change proportional
60
6
5
4
in
11
. The output will regulate at a level of −V
+
Curve
A
B
R
R
1
2
V
3.3 V
5.0 V
in
+
(V)
−V
out
V
4.5
6.5
z
(V)
Z
+ V
th(SHDN)
V
out
−2.8
−3.8
(V)
. Note that