LM723,LM723C
LM723/LM723C Voltage Regulator
Literature Number: SNVS765B
LM723/LM723C
Voltage Regulator
General Description
The LM723/LM723C is a voltage regulator designed prima-
rily for series regulator applications. By itself, it will supply
output currents up to 150 mA; but external transistors can be
added to provide any desired load current. The circuit fea-
tures extremely low standby current drain, and provision is
made for either linear or foldback current limiting.
The LM723/LM723C is also useful in a wide range of other
applications such as a shunt regulator, a current regulator or
a temperature controller.
The LM723C is identical to the LM723 except that the
LM723C has its performance guaranteed over a 0˚C to
+70˚C temperature range, instead of −55˚C to +125˚C.
Features
n150 mA output current without external pass transistor
nOutput currents in excess of 10A possible by adding
external transistors
nInput voltage 40V max
nOutput voltage adjustable from 2V to 37V
nCan be used as either a linear or a switching regulator
Connection Diagrams
Dual-In-Line Package Metal Can Package
00856302
Top View
Order Number LM723J/883 or LM723CN
See NS Package J14A or N14A
00856303
Note: Pin 5 connected to case.
Top View
Order Number LM723H, LM723H/883 or LM723CH
See NS Package H10C
00856320
Top View
Order Number LM723E/883
See NS Package E20A
June 1999
LM723/LM723C Voltage Regulator
© 2004 National Semiconductor Corporation DS008563 www.national.com
Equivalent Circuit*
00856304
*Pin numbers refer to metal can package.
Typical Application
00856308
for minimum temperature drift.
Typical Performance
Regulated Output Voltage 5V
Line Regulation (∆V
IN
= 3V) 0.5mV
Load Regulation (∆I
L
= 50 mA) 1.5mV
FIGURE 1. Basic Low Voltage Regulator
(V
OUT
= 2 to 7 Volts)
LM723/LM723C
www.national.com 2
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
(Note 10)
Pulse Voltage from V
+
to V
−
(50 ms) 50V
Continuous Voltage from V
+
to V
−
40V
Input-Output Voltage Differential 40V
Maximum Amplifier Input Voltage
(Either Input) 8.5V
Maximum Amplifier Input Voltage
(Differential) 5V
Current from V
Z
25 mA
Current from V
REF
15 mA
Internal Power Dissipation
Metal Can (Note 2) 800 mW
Cavity DIP (Note 2) 900 mW
Molded DIP (Note 2) 660 mW
Operating Temperature Range
LM723 −55˚C to +150˚C
LM723C 0˚C to +70˚C
Storage Temperature Range
Metal Can −65˚C to +150˚C
Molded DIP −55˚C to +150˚C
Lead Temperature (Soldering, 4 sec. max.)
Hermetic Package 300˚C
Plastic Package 260˚C
ESD Tolerance 1200V
(Human body model, 1.5 kΩin series with 100 pF)
Electrical Characteristics (Note 3) (Note 10)
Parameter Conditions LM723 LM723C Units
Min Typ Max Min Typ Max
Line Regulation V
IN
= 12V to V
IN
= 15V 0.01 0.1 0.01 0.1 %
V
OUT
−55˚C ≤T
A
≤+125˚C 0.3 %
V
OUT
0˚C ≤T
A
≤+70˚C 0.3 %
V
OUT
V
IN
= 12V to V
IN
= 40V 0.02 0.2 0.1 0.5 %
V
OUT
Load Regulation I
L
=1mAtoI
L
= 50 mA 0.03 0.15 0.03 0.2 %
V
OUT
−55˚C ≤T
A
≤+125˚C 0.6 %
V
OUT
0˚C ≤T
A
≤+70˚C 0.6 %
V
OUT
Ripple Rejection f = 50 Hz to 10 kHz, C
REF
= 0 74 74 dB
f = 50 Hz to 10 kHz, C
REF
=5µF 86 86 dB
Average Temperature Coeffic- −55˚C ≤T
A
≤+125˚C 0.002 0.015 %/˚C
ient of Output Voltage (Note 8) 0˚C ≤T
A
≤+70˚C 0.003 0.015 %/˚C
Short Circuit Current Limit R
SC
=10Ω,V
OUT
= 0 65 65 mA
Reference Voltage 6.95 7.15 7.35 6.80 7.15 7.50 V
Output Noise Voltage BW = 100 Hz to 10 kHz, C
REF
= 0 86 86 µVrms
BW = 100 Hz to 10 kHz, C
REF
=5
µF
2.5 2.5 µVrms
Long Term Stability 0.05 0.05 %/1000
hrs
Standby Current Drain I
L
=0,V
IN
= 30V 1.7 3.5 1.7 4.0 mA
Input Voltage Range 9.5 40 9.5 40 V
Output Voltage Range 2.0 37 2.0 37 V
Input-Output Voltage
Differential
3.0 38 3.0 38 V
θ
JA
Molded DIP 105 ˚C/W
θ
JA
Cavity DIP 150 ˚C/W
θ
JA
H10C Board Mount in Still Air 165 165 ˚C/W
LM723/LM723C
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Electrical Characteristics (Note 3) (Note 10) (Continued)
Parameter Conditions LM723 LM723C Units
Min Typ Max Min Typ Max
θ
JA
H10C Board Mount in 400 LF/Min
Air Flow
66 66 ˚C/W
θ
JC
22 22 ˚C/W
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: See derating curves for maximum power rating above 25˚C.
Note 3: Unless otherwise specified, TA= 25˚C, VIN =V
+=V
C= 12V, V−=0,V
OUT =5V,I
L= 1 mA, RSC =0,C
1= 100 pF, CREF = 0 and divider impedance as seen
by error amplifier ≤10 kΩconnected as shown in Figure 1. Line and load regulation specifications are given for the condition of constant chip temperature.
Temperature drifts must be taken into account separately for high dissipation conditions.
Note 4: L1is 40 turns of No. 20 enameled copper wire wound on Ferroxcube P36/22-3B7 pot core or equivalent with 0.009 in. air gap.
Note 5: Figures in parentheses may be used if R1/R2 divider is placed on opposite input of error amp.
Note 6: Replace R1/R2 in figures with divider shown in Figure 13.
Note 7: V+and VCC must be connected to a +3V or greater supply.
Note 8: For metal can applications where VZis required, an external 6.2V zener diode should be connected in series with VOUT.
Note 9: Guaranteed by correlation to other tests.
Note 10: A military RETS specification is available on request. At the time of printing, the LM723 RETS specification complied with the Min and Max limits in this
table. The LM723E, H, and J may also be procured as a Standard Military Drawing.
Typical Performance Characteristics
Load Regulation
Characteristics with
Current Limiting
Load Regulation
Characteristics with
Current Limiting
00856322 00856323
Load & Line Regulation vs
Input-Output Voltage
Differential
Current Limiting
Characteristics
00856324 00856325
LM723/LM723C
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Typical Performance Characteristics (Continued)
Current Limiting
Characteristics vs
Junction Temperature
Standby Current Drain vs
Input Voltage
00856326 00856327
Line Transient Response Load Transient Response
00856328 00856329
Output Impedence vs
Frequency
00856330
LM723/LM723C
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Maximum Power Ratings
Noise vs Filter Capacitor
(C
REF
in Circuit of Figure 1)
(Bandwidth 100 Hz to 10 kHz)
LM723
Power Dissipation vs
Ambient Temperature
00856331 00856332
LM723C
Power Dissipation vs
Ambient Temperature
00856333
TABLE 1. Resistor Values (kΩ) for Standard Output Voltage
Positive Applicable Fixed Output Negative Fixed 5% Output
Output Figures Output Adjustable Output Applicable Output Adjustable
Voltage ±5% ±10% (Note 6) Voltage Figures ±5% ±10%
(Note 5) R1 R2 R1 P1 R2 R1 R2 R1 P1 R2
+3.0 1, 5, 6, 9, 12 (4) 4.12 3.01 1.8 0.5 1.2 +100 7 3.57 102 2.2 10 91
+3.6 1, 5, 6, 9, 12 (4) 3.57 3.65 1.5 0.5 1.5 +250 7 3.57 255 2.2 10 240
+5.0 1, 5, 6, 9, 12 (4) 2.15 4.99 0.75 0.5 2.2 −6 (Note 7) 3, (10) 3.57 2.43 1.2 0.5 0.75
+6.0 1, 5, 6, 9, 12 (4) 1.15 6.04 0.5 0.5 2.7 −9 3, 10 3.48 5.36 1.2 0.5 2.0
+9.0 2, 4, (5, 6, 9, 12) 1.87 7.15 0.75 1.0 2.7 −12 3, 10 3.57 8.45 1.2 0.5 3.3
+12 2, 4, (5, 6, 9, 12) 4.87 7.15 2.0 1.0 3.0 −15 3, 10 3.65 11.5 1.2 0.5 4.3
+15 2, 4, (5, 6, 9, 12) 7.87 7.15 3.3 1.0 3.0 −28 3, 10 3.57 24.3 1.2 0.5 10
+28 2, 4, (5, 6, 9, 12) 21.0 7.15 5.6 1.0 2.0 −45 8 3.57 41.2 2.2 10 33
+45 7 3.57 48.7 2.2 10 39 −100 8 3.57 97.6 2.2 10 91
+75 7 3.57 78.7 2.2 10 68 −250 8 3.57 249 2.2 10 240
LM723/LM723C
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TABLE 2. Formulae for Intermediate Output Voltages
Outputs from +2 to +7 volts Outputs from +4 to +250 volts Current Limiting
(Figures 1, 4, 5, 6, 9, 12 (Figure 7)
Outputs from +7 to +37 volts Outputs from −6 to −250 volts Foldback Current Limiting
(Figures 2, 4, 5, 6, 9, 12)(Figures 3, 8, 10)
Typical Applications
00856309
for minimum temperature drift.
R3 may be eliminated for
minimum component count.
Typical Performance
Regulated Output Voltage 15V
Line Regulation (∆V
IN
= 3V) 1.5 mV
Load Regulation (∆I
L
= 50 mA) 4.5 mV
FIGURE 2. Basic High Voltage Regulator
(V
OUT
= 7 to 37 Volts)
00856310
Typical Performance
Regulated Output Voltage −15V
Line Regulation (∆V
IN
= 3V) 1 mV
Load Regulation (∆I
L
= 100 mA) 2 mV
FIGURE 3. Negative Voltage Regulator
LM723/LM723C
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Typical Applications (Continued)
00856311
Typical Performance
Regulated Output Voltage +15V
Line Regulation (∆V
IN
= 3V) 1.5 mV
Typical Performance
Load Regulation (∆I
L
= 1A) 15 mV
FIGURE 4. Positive Voltage Regulator
(External NPN Pass Transistor)
00856312
Typical Performance
Regulated Output Voltage +5V
Line Regulation (∆V
IN
= 3V) 0.5 mV
Typical Performance
Load Regulation (∆I
L
= 1A) 5 mV
FIGURE 5. Positive Voltage Regulator
(External PNP Pass Transistor)
LM723/LM723C
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Typical Applications (Continued)
00856313
Typical Performance
Regulated Output Voltage +5V
Line Regulation (∆V
IN
= 3V) 0.5 mV
Typical Performance
Load Regulation (∆I
L
=10mA) 1mV
Short Circuit Current 20 mA
FIGURE 6. Foldback Current Limiting
00856314
Typical Performance
Regulated Output Voltage +50V
Line Regulation (∆V
IN
= 20V) 15 mV
Load Regulation (∆I
L
= 50 mA) 20 mV
FIGURE 7. Positive Floating Regulator
LM723/LM723C
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Typical Applications (Continued)
00856315
Typical Performance
Regulated Output Voltage −100V
Line Regulation (∆V
IN
= 20V) 30 mV
Load Regulation (∆I
L
= 100 mA) 20 mV
FIGURE 8. Negative Floating Regulator
00856316
Typical Performance
Regulated Output Voltage +5V
Line Regulation (∆V
IN
= 30V) 10 mV
Load Regulation (∆I
L
= 2A) 80 mV
FIGURE 9. Positive Switching Regulator
LM723/LM723C
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Typical Applications (Continued)
00856317
Typical Performance
Regulated Output Voltage −15V
Line Regulation (∆V
IN
= 20V) 8 mV
Load Regulation (∆I
L
= 2A) 6 mV
FIGURE 10. Negative Switching Regulator
00856318
Note: Current limit transistor may be used for shutdown if current limiting is not required.
Typical Performance
Regulated Output Voltage +5V
Line Regulation (∆V
IN
= 3V) 0.5 mV
Load Regulation (∆I
L
= 50 mA) 1.5 mV
FIGURE 11. Remote Shutdown Regulator with Current Limiting
LM723/LM723C
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Typical Applications (Continued)
00856319
Regulated Output Voltage +5V
Line Regulation (∆V
IN
= 10V) 0.5 mV
Load Regulation (∆I
L
= 100 mA) 1.5 mV
FIGURE 12. Shunt Regulator
00856321
FIGURE 13. Output Voltage Adjust
(Note 6)
LM723/LM723C
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Schematic Diagram
00856301
LM723/LM723C
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Physical Dimensions inches (millimeters)
unless otherwise noted
Leadless Chip Carrier Package (E)
Order Number LM723E/883
NS Package E20A
Metal Can Package (H)
Order Number LM723H, LM723H/883 or LM723CH
NS Package H10C
LM723/LM723C
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
Ceramic Dual-In-Line Package (J)
Order Number LM723J/883
NS Package J14A
LM723/LM723C
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
Molded Dual-In-Line Package (N)
Order Number LM723CN
NS Package N14A
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.
For the most current product information visit us at www.national.com.
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LM723/LM723C Voltage Regulator
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