NSC LM123K

LM123/LM323A/LM323
3-Amp, 5-Volt Positive Regulator
General Description
The LM123 is a three-terminal positive regulator with a preset 5V output and a load driving capability of 3 amps. New
circuit design and processing techniques are used to provide
the high output current without sacrificing the regulation
characteristics of lower current devices.
The LM323A offers improved precision over the standard
LM323. Parameters with tightened specifications include
output voltage tolerance, line regulation, and load regulation.
The 3 amp regulator is virtually blowout proof. Current limiting, power limiting, and thermal shutdown provide the same
high level of reliability obtained with these techniques in the
LM109 1 amp regulator.
No external components are required for operation of the
LM123. If the device is more than 4 inches from the filter capacitor, however, a 1 µF solid tantalum capacitor should be
used on the input. A 0.1 µF or larger capacitor may be used
on the output to reduce load transient spikes created by fast
switching digital logic, or to swamp out stray load capacitance.
An overall worst case specification for the combined effects
of input voltage, load currents, ambient temperature, and
power dissipation ensure that the LM123 will perform satisfactorily as a system element.
For applications requiring other voltages, see LM150 series
adjustable regulator data sheet.
Operation is guaranteed over the junction temperature range
−55˚C to +150˚C for LM123, −40˚C to +125˚C for LM323A,
and 0˚C to +125˚C for LM323. A hermetic TO-3 package is
used for high reliability and low thermal resistance.
Features
n
n
n
n
n
n
n
Guaranteed 1% initial accuracy (A version)
3 amp output current
Internal current and thermal limiting
0.01Ω typical output impedance
7.5V minimum input voltage
30W power dissipation
P+ Product Enhancement tested
Connection Diagram
Metal Can Package
DS007771-2
Order Number LM123K STEEL, LM323AK STEEL or LM323K STEEL
See NS Package Number K02A
Order Number LM123K/883
See NS Package Number K02C
Typical Applications
Basic 3 Amp Regulator
DS007771-3
*Required if LM123 is more than 4" from filter capacitor.
†Regulator is stable with no load capacitor into resistive loads.
© 1999 National Semiconductor Corporation
DS007771
www.national.com
LM123/LM323A/LM323 3-Amp, 5-Volt Positive Regulator
April 1998
Absolute Maximum Ratings (Note 1)
Operating Junction Temperature Range
LM123
LM323A
LM323
Storage Temperature Range
Lead Temperature (Soldering, 10 sec.)
ESD Tolerance (Note 5)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
(Note 5)
Input Voltage
Power Dissipation
20V
Internally Limited
LM123 Electrical Characteristics
Parameter
Output Voltage
−55˚C
−40˚C
0˚C
−65˚C
to
to
to
to
+150˚C
+125˚C
+125˚C
+150˚C
300˚C
2000V
(Note 2)
Conditions
LM123
Units
Min
Typ
Max
Tj = 25˚C
VIN = 7.5V, IOUT = 0A
4.7
5
5.3
V
7.5V ≤ VIN ≤ 15V
4.6
5.4
V
Line Regulation (Note 4)
0A ≤ IOUT ≤ 3A, P ≤ 30W
Tj = 25˚C
5
25
mV
Load Regulation (Note 4)
7.5V ≤ VIN ≤ 15V
Tj = 25˚C, VIN = 7.5V,
25
100
mV
20
mA
0A ≤ IOUT ≤ 3A
Quiescent Current
7.5V ≤ VIN ≤ 15V,
12
Output Noise Voltage
0A ≤ IOUT ≤ 3A
Tj = 25˚C
40
Short Circuit Current Limit
10 Hz ≤ f ≤ 100 kHz
Tj = 25˚C
VIN = 15V
VIN = 7.5V
µVrms
3
4.5
4
5
A
35
mV
Long Term Stability
Thermal Resistance Junction
to Case (Note 3)
2
LM323A/LM323 Electrical Characteristics
Parameter
Output Voltage
A
˚C/W
(Note 2)
Conditions
LM323A
LM323
Units
Min
Typ
Max
Min
Typ
Max
Tj = 25˚C
VIN = 7.5V, IOUT = 0A
4.95
5
5.05
4.8
5
5.2
V
7.5V ≤ VIN ≤ 15V
4.85
5.15
4.75
5.25
V
Line Regulation (Note 4)
0A ≤ IOUT ≤ 3A, P ≤ 30W
Tj = 25˚C
5
10
5
25
mV
Load Regulation (Note 4)
7.5V ≤ VIN ≤ 15V
Tj = 25˚C, VIN = 7.5V,
25
50
25
100
mV
20
12
20
mA
0A ≤ IOUT ≤ 3A
Quiescent Current
7.5V ≤ VIN ≤ 15V,
12
Output Noise Voltage
0A ≤ IOUT ≤ 3A
Tj = 25˚C
40
Short Circuit Current Limit
10 Hz ≤ f ≤ 100 kHz
Tj = 25˚C
VIN = 15V
VIN = 7.5V
4.5
3
4.5
4
6
4
5
A
35
mV
35
Thermal Resistance Junction
to Case (Note 3)
2
2
µVrms
3
Long Term Stability
www.national.com
40
2
A
˚C/W
LM323A/LM323 Electrical Characteristics
(Note 2) (Continued)
Note 1: “Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits.
Note 2: Unless otherwise noted, specifications apply for −55˚C ≤ Tj ≤ +150˚C for the LM123, −40˚C ≤ Tj ≤ +125˚C for the LM323A, and 0˚C ≤ Tj ≤ +125˚C for the
LM323. Although power dissipation is internally limited, specifications apply only for P ≤ 30W.
Note 3: Without a heat sink, the thermal resistance of the TO-3 package is about 35˚C/W. With a heat sink, the effective thermal resistance can only approach the
specified values of 2˚C/W, depending on the efficiency of the heat sink.
Note 4: Load and line regulation are specified at constant junction temperature. Pulse testing is required with a pulse width ≤ 1 ms and a duty cycle ≤ 5%.
Note 5: Refer to RETS123K drawing for LM123K military specifications.
Note 6: Human body model, 1.5 kΩ in series with 100 pF.
Typical Performance Characteristics
Maximum Average Power
Dissipation for LM123
Maximum Average Power
Dissipation for LM323A, LM323
Output Impedance
DS007771-11
DS007771-10
DS007771-9
Peak Available Output Current
Short Circuit Current
DS007771-13
DS007771-12
Dropout Voltage
Ripple Rejection
Line Transient Response
Output Voltage
DS007771-16
DS007771-15
3
DS007771-14
DS007771-17
www.national.com
Typical Performance Characteristics
Quiescent Current
(Continued)
Load Transient Response
DS007771-18
Output Noise Voltage
DS007771-19
DS007771-20
Typical Applications
10 Amp Regulator with Complete Overload Protection
DS007771-6
*Select for 20 mA Current from Unregulated Negative Supply
www.national.com
4
Typical Applications
(Continued)
Adjustable Regulator 0V−10V @ 3A
DS007771-7
A1 — LM101A
C1 — 2 µF Optional — Improves Ripple Rejection, Noise, and Transient Response
Trimming Output to 5V
DS007771-8
Adjustable Output 5V−10V 0.1% Regulation
DS007771-4
*Select to Set Output Voltage
**Select to Draw 25 mA from V−
5
www.national.com
Schematic Diagram
DS007771-1
www.national.com
6
Physical Dimensions
inches (millimeters) unless otherwise noted
Metal Can Package (K)
Order Number LM123K STEEL, LM323AK STEEL or LM323K STEEL
NS Package Number K02A
7
www.national.com
LM123/LM323A/LM323 3-Amp, 5-Volt Positive Regulator
Physical Dimensions
inches (millimeters) unless otherwise noted (Continued)
Metal Can Package (K)
Mil-Aero Product
Order Number LM123K/883
NS Package Number K02C
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and
whose failure to perform when properly used in
accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a
significant injury to the user.
National Semiconductor
Corporation
Americas
Tel: 1-800-272-9959
Fax: 1-800-737-7018
Email: [email protected]
www.national.com
National Semiconductor
Europe
Fax: +49 (0) 1 80-530 85 86
Email: [email protected]
Deutsch Tel: +49 (0) 1 80-530 85 85
English Tel: +49 (0) 1 80-532 78 32
Français Tel: +49 (0) 1 80-532 93 58
Italiano Tel: +49 (0) 1 80-534 16 80
2. A critical component is any component of a life
support device or system whose failure to perform
can be reasonably expected to cause the failure of
the life support device or system, or to affect its
safety or effectiveness.
National Semiconductor
Asia Pacific Customer
Response Group
Tel: 65-2544466
Fax: 65-2504466
Email: [email protected]
National Semiconductor
Japan Ltd.
Tel: 81-3-5639-7560
Fax: 81-3-5639-7507
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.