Motorola LM323AT, LM323T Datasheet

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The LM323,A are monolithic integrated circuits which supply a fixed
positive 5.0 V output with a load driving capability in excess of 3.0 A. These
three–terminal regulators employ internal current limiting, thermal shutdown,
and safe–area compensation. The A–suffix is an improved device with
superior electrical characteristics and a 2% output voltage tolerance. These
regulators are offered with a 0° to +125°C temperature range in a low cost
plastic power package.

Although designed primarily as a fixed voltage regulator, these devices
can be used with external components to obtain adjustable voltages and
currents. These devices can be used with a series pass transistor to supply
up to 15 A at 5.0 V.

• Output Current in Excess of 3.0 A

• Available with 2% Output Voltage Tolerance

• No External Components Required

• Internal Thermal Overload Protection

• Internal Short Circuit Current Limiting

• Output Transistor Safe–Area Compensation

• Thermal Regulation and Ripple Rejection Have Specified Limits

Order this document by LM323/D

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3–AMPERE, 5 VOLT

POSITIVE

VOLTAGE REGULATORS

SEMICONDUCTOR

TECHNICAL DATA

T SUFFIX

PLASTIC PACKAGE

CASE 221A

Pin 1. Input

2. Ground

3. Output

1

2

3

Simplified Application

Input

Cin*

0.33

µ

F

A common ground is required between the input and the output voltages. The input
voltage must remain typically 2.5 V above the output voltage even during the low point
on the input ripple voltage.

LM323, A

Output

CO**

Heatsink surface is connected to Pin 2.

ORDERING INFORMATION

*Cin is required if regulator is located an appreciable

*distance from power supply filter. (See Applications

*Information for details.)

**CO is not needed for stability; however, it does

**improve transient response.

MOTOROLA ANALOG IC DEVICE DATA

Output

Voltage

Device

LM323T
LM323A T

 Motorola, Inc. 1996 Rev 0

Tolerance

4%
2%

Operating

Temperature

Range

TJ = 0° to +125°C

Package

Plastic
Power

1

MAXIMUM RATINGS

Rating Symbol Value Unit

Input Voltage V
Power Dissipation P
Operating Junction Temperature Range T
Storage Temperature Range T
Lead Temperature (Soldering, 10 s) T

in
D

J

stg

solder

LM323, A

20 Vdc

Internally Limited W

0 to +125 °C

–65 to +150 °C

300 °C

ELECTRICAL CHARACTERISTICS (T

J

= T

low

to T

[Note 1], unless otherwise noted.)

high

LM323A LM323

Characteristics Symbol Min Typ Max Min Typ Max Unit

Output Voltage

(Vin = 7.5 V, 0 ≤ I

≤ 3.0 A, TJ = 25°C)

out

Output Voltage

(7.5 V ≤ Vin ≤ 15 V, 0 ≤ I
P ≤ P

max

) (Note 2)

≤ 3.0 A,

out

Line Regulation

(7.5 V ≤ Vin ≤ 15 V, TJ = 25°C) (Note 3)

Load Regulation

(Vin = 7.5 V, 0 ≤ I
(Note 3)

≤ 3.0 A, TJ = 25°C)

out

Thermal Regulation

(Pulse = 10 ms, P = 20 W, TA = 25°C)

Quiescent Current

(7.5 V ≤ Vin ≤ 15 V, 0 ≤ I

out

≤ 3.0 A)

Output Noise Voltage

(10 Hz ≤ f ≤ 100 kHz, TJ = 25°C)

Ripple Rejection

(8.0 V ≤ Vin ≤ 18 V, I
f = 120 Hz, TJ = 25°C)

out

= 2.0A,

Short Circuit Current Limit

(Vin = 15 V, TJ = 25°C)
(Vin = 7.5 V, TJ = 25°C)

Reg

Reg

Reg

V

O

V

O

line

load

therm

I

B

V

N

4.9 5.0 5.1 4.8 5.0 5.2 V

4.8 5.0 5.2 4.75 5.0 5.25 V

– 1.0 15 – 1.0 25 mV

– 10 50 – 10 100 mV

– 0.001 0.01 – 0.002 0.03 %VO/W

– 3.5 10 – 3.5 20 mA

– 40 – – 40 – µV

RR 66 75 – 62 75 – dB

I

SC

–
–

4.5

5.5

–
–

–
–

4.5

5.5

–

–
Long Term Stability S – – 35 – – 35 mV
Thermal Resistance, Junction–to–Case (Note 4) R

NOTES: 1.T

to T

low

2.Although power dissipation is internally limited, specifications apply only for P ≤ P

3.Load and line regulation are specified at constant junction temperature. Pulse testing is required with a pulse width ≤ 1.0 ms and a duty cycle ≤ 5%.

4.Without a heatsink, the thermal resistance (R

2.0°C/W, depending on the ef ficiency of the heatsink.

= 0° to +125°C

high

θJA

ΘJC

is 65°C/W). With a heatsink, the effective thermal resistance can approach the specified values of

– 2.0 – – 2.0 – °C/W

= 25 W.

max

rms

A

2

MOTOROLA ANALOG IC DEVICE DATA

LM323, A

Representative Schematic Diagram

Q1

Q4

Q5

Q6 Q7

1.0k

300

Q3 10k

Q12

Q11

6.0k

Q8

2.0k
Q13

Q14

Q2

Q10

1.0k

2.6k

3.9k

Q9

6.0k

3.0k

5.6k

40pF

Q17 Q18

Q15

2.8k

VOLTAGE REGULATOR PERFORMANCE

The performance of a voltage regulator is specified by its
immunity to changes in load, input voltage, power dissipation,
and temperature. Line and load regulation are tested with a
pulse of short duration (< 100 µs) 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.

Thermal regulation is defined as the change in output
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

2

210

Q24

Q21

100

200

Q25

Q26

13

200

Q20

Q16

Q19

1.0k

10pF

Q23

7.2k

Q22

6.7V

50520

16k

300

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.

Figure 1 shows the line and thermal regulation response of
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 Á. Figure 2 shows
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 Á.

Input

Q27

0.12

Output

840

1.7k

Gnd

Figure 1. Line and Thermal Regulation Figure 2. Load and Thermal Regulation

2

, OUTPUT

out

V

∆

VOLTAGE DEVIATION (V)

, INPUT

in

V

(2.0 mV/DIV)

18 V

8.0 V

VOLTAGE (V)

V

= 5.0 V

out

Vin = 8.0 V
I

= 2.0 A

out

→

18 V → 8.0 V

1

t, TIME (2.0 ms/DIV)

1

= Reg

2

MOTOROLA ANALOG IC DEVICE DATA

= 2.4 mV

line

= 0.0015% VO/W

therm

2

, OUTPUT

out

V

∆

(2.0 mV/DIV)

, OUTPUT

out

I

CURRENT (A) VOLTAGE DEVIA TION (V)

2

2.0

0

V

= 5.0 V

out

Vin = 15 V
I

= 0 A

out

→

2.0 A → 0 A

2

1

t, TIME (2.0 ms/DIV)

= Reg

1

line

= Reg

2

therm

= 5.4 mV

= 0.0015% VO/W= Reg

3