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LM323, A
5
MOTOROLA ANALOG IC DEVICE DATA
I
V
D
V
D
V
C
V
V
Figure 9. Dropout Voltage
Figure 10. Short Circuit Current
0
10
20
30
40
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
1.0
0.5
0
t, TIME (
μ
s)
Iout = 150 mA
CO = 0
TJ = 25
°
C
1.0
C
0
10
20
30
40
t, TIME (
μ
s)
Vin = 10 V
CO = 0
TJ = 25
°
C
0.3
0.2
0.1
0
–0.1
–0.2
–0.3
1.5
0.5
0
Figure 11. Line Transient Response
Figure 12. Load Transient Response
2.5
2.0
1.5
1.0
0.5–90
–50
–10
30
70
110
150
190
TJ, JUNCTION TEMPERATURE (
°
C)
Iout = 3.0 A
Iout = 1.0 A
Iout = 0.5 A
Vout = 50 mV
8.0
6.0
4.0
2.0
05.0
10
15
20
25
S
I
Z
Vin, INPUT VOLTAGE (Vdc)
,
TJ = 0
°
C
TJ = 25
°
C
TJ = 125
°
C
APPLICATIONS INFORMATION
Design Considerations
The LM323,A series of fixed voltage regulators are
designed with Thermal Overload Protection that shuts down
the circuit when subjected to an excessive power overload
condition, Internal Short Circuit Protection that limits the
maximum current the circuit will pass, and Output Transistor
Safe–Area Compensation that reduces the output short
circuit current as the voltage across the pass transistor is
increased.
In many low current applications, compensation
capacitors are not required. However, it is recommended that
the regulator input be bypassed with a capacitor if the
regulator is connected to the power supply filter with long wire
lengths, or if the output load capacitance is large. An input
bypass capacitor should be selected to provide good
high–frequency characteristics to insure stable operation
under all load conditions. A 0.33
μ
F or larger tantalum, mylar,
or other capacitor having low internal impedance at high
frequencies should be chosen. The bypass capacitor should
be mounted with the shortest possible leads directly across
the regulator’s input terminals. Normally good construction
techniques should be used to minimize ground loops and
lead resistance drops since the regulator has no external
sense lead.