LM323 ON Semiconductor, LM323 Datasheet - Page 3

• Manufacturer Part Number: LM323
• Description: 3-AMPERE/ 5 VOLT POSITIVE VOLTAGE REGULATORS
• Manufacturer: ON Semiconductor

immunity to changes in load, input voltage, power dissipation,
and temperature. Line and load regulation are tested with a
pulse of short duration (< 100 s) and are strictly a function of
electrical gain. However, pulse widths of longer duration
(> 1.0 ms) are sufficient to affect temperature gradients
across the die. These temperature gradients can cause a
change in the output voltage, in addition to changes by line
and load regulation. Longer pulse widths and thermal
gradients make it desirable to specify thermal regulation.
voltage caused by a change in dissipated power for a
specified time, and is expressed as a percentage output
voltage change per watt. The change in dissipated power can
MOTOROLA ANALOG IC DEVICE DATA
The performance of a voltage regulator is specified by its
Thermal regulation is defined as the change in output
Q4
Q6
8.0 V
18 V
Q5
V out = 5.0 V
V in = 8.0 V
I out = 2.0 A
Figure 1. Line and Thermal Regulation
Q1
Q3
1.0k
300
Q7
Q11
18 V
6.0k
Q12
10k
t, TIME (2.0 ms/DIV)
Q8
8.0 V
2.0k 3.9k
Q13
Q14
1
Q2
Q10
520
2.6k
1.0k
Q9
1
2
VOLTAGE REGULATOR PERFORMANCE
= Reg line = 2.4 mV
= Reg therm = 0.0015% V O /W
6.0k
2
Representative Schematic Diagram
Q17
Q15
2.8k
Q18
LM323, A
3.0k
5.6k
40pF
Q16
Q20
2
Q19
be caused by a change in either input voltage or the load
current. Thermal regulation is a function of IC layout and die
attach techniques, and usually occurs within 10 ms of a
change in power dissipation. After 10 ms, additional changes
in the output voltage are due to the temperature coefficient of
the device.
a typical LM323A to a 20 W input pulse. The variation of the
output voltage due to line regulation is labeled À and the
thermal regulation component is labeled
the load and thermal regulation response of a typical LM323A
to a 20 W load pulse. The output voltage variation due to load
regulation is labeled À and the thermal regulation component
is labeled .
1.0k
Figure 1 shows the line and thermal regulation response of
10pF
Q23
7.2k
Q22
6.7V
2
50
2.0
V out = 5.0 V
V in = 15 V
I out = 0 A
0
Figure 2. Load and Thermal Regulation
16k
300
210
2.0 A
Q24
2
2
Q21
t, TIME (2.0 ms/DIV)
0 A
200
100
1
2
1
= Reg line = 5.4 mV
= Reg therm = 0.0015% V O /W
Q25
200
. Figure 2 shows
Q26
13
Q27
840
1.7k
0.12
Input
Output
Gnd
3