November 2007 Rev 6 1/21
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LM723
High precision voltage regulator
Features
■Input voltage up to 40 V
■Output voltage adjustable from 2 to 37 V
■Positive or negative supply operation
■Series, shunt, switching or floating operation
■Output current to 150 mA without external pass
transistor
■Adjustable current limiting
Description
The LM723 is a monolithic integrated
programmable voltage regulator, assembled in
14-lead dual in-line plastic package. The circuit
provides internal current limiting. When the output
current exceeds 150 mA an external NPN or PNP
pass element may be used. Provisions are made
for adjustable current limiting and remote shut-
down.
DIP-14
Table 1. Device summary
Order code Package
LM723N DIP-14
LM723CN DIP-14
www.st.com
Contents LM723
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Contents
1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4 Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6 Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7 Applications information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
8 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
LM723 Diagram
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1 Diagram
Figure 1. Schematic diagram
Pin configuration LM723
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2 Pin configuration
Figure 2. Pin connections (top view)
LM723 Maximum ratings
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3 Maximum ratings
Table 2. Absolute maximum ratings
Symbol Parameter
Value
Unit
LM723 LM723C
VIDC input voltage 40 40 V
ΔVI-O Dropout voltage 40 40 V
IOOutput current 150 150 mA
IREF Current from VREF 15 25 mA
TOP Operating Temperature -55 to 125 0 to 70 °C
TSTG Storage Temperature -65 to 150 -65 to 150 °C
TJJunction Temperature 150 125 °C
Table 3. Thermal data
Symbol Parameter DIP14 Unit
RthJA Thermal resistance junction-ambient Max 200 °C/W
Circuit LM723
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4 Circuit
Note: VI = 12 V; VO = 5 V; IO = 1 mA; R1/R2
≤
10 k
Ω
Figure 3. Test circuit (pin configuration relative to the plastic package)
LM723 Electrical characteristics
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5 Electrical characteristics
Table 4. Electrical characteristics for LM723 (refer to the test circuits, TA = 25 °C, unless
otherwise specified.)
Symbol Parameter Test conditions Min. Typ. Max. Unit
ΔVO/ΔVILine regulation
VI = 12 to 15 V 0.01 0.1
%VI = 12 to 40 V 0.02 0.2
VI = 12 to 15 V, TA = -55 to 125°C 0.3
ΔVO/VOLoad regulation IO = 1 to 50 mA 0.03 0.15 %
IO = 1 to 10 mA, TA = -55 to 125°C 0.6
VREF Reference voltage IREF = 160 µA 6.95 7.15 7.35 V
SVR Supply voltage rejection f = 100 Hz to 10kHz CREF = 0 74 dB
CREF = 5µF 86
ΔVO/ΔT Output voltage drift 150 ppm/°C
ISC Output current limit RSC = 10Ω, VO = 0 V 65 mA
VIInput voltage range 9.5 40 V
VOOutput voltage range 2 37 V
VO-VI338V
IdQuiescent current VI = 30V, IO = 0 mA 2.3 5 mA
KVH Long term stability 0.1 %/1000
hrs
eN Output noise voltage BW = 100 Hz to 10 kHz CREF = 0 20 µV
CREF = 5µF 2.5
Electrical characteristics LM723
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Table 5. Electrical characteristics for LM723C (refer to the test circuits, TA = 25 °C, unless
otherwise specified.)
Symbol Parameter Test conditions Min. Typ. Max. Unit
ΔVO/ΔVILine regulation
VI = 12 to 15 V 0.01 0.1
%VI = 12 to 40 V 0.1 0.5
VI = 12 to 15 V, TA = 0 to 70°C 0.3
ΔVO/VOLoad regulation IO = 1 to 50 mA 0.03 0.2 %
IO = 1 to 10 mA, TA = 0 to 70°C 0.6
VREF Reference voltage IREF = 160 µA 6.8 7.15 7.5 V
SVR Supply voltage rejection f = 100 Hz to 10kHz CREF = 0 74 dB
CREF = 5µF 86
ΔVO/ΔT Output voltage drift 150 ppm/°C
ISC Output current limit RSC = 10Ω, VO = 0 V 65 mA
VIInput voltage range 9.5 40 V
VOOutput voltage range 2 37 V
VO-VI338V
IdQuiescent current VI = 30V, IO = 0 mA 2.3 4 mA
KVH Long term stability 0.1 %/1000
hrs
eN Output noise voltage BW = 100 Hz to 10 kHz CREF = 0 20 µV
CREF = 5µF 2.5
LM723 Typical performance characteristics
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6 Typical performance characteristics
(unless otherwise specified VO(NOM) = 3.3 V)
Figure 4. Maximum output current vs voltage
drop
Figure 5. Current limiting characteristics
Figure 6. Current limiting characteristics vs
junction temperature
Figure 7. Load regulation characteristics
without current limiting
Figure 8. Load regulation characteristics
with current limiting
Figure 9. Load regulation characteristics
with current limiting
Typical performance characteristics LM723
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Figure 10. Line regulation vs voltage drop Figure 11. Load regulation vs voltage drop
Figure 12. Quiescent drain current vs input
voltage
Figure 13. Line transient response
Figure 14. Load transient response Figure 15. Output impedance vs frequency
LM723 Typical performance characteristics
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Table 6. Resistor values (kΩ) for standard output voltages
Output
Volt age Applicable figures
Fixed output ± 5% Output adjustable ± 10% (1)
R1 R2 R1 P1 R2
+3 16, 18, 20, 21, 24, 26 4.12 3.01 1.8 0.5 1.2
+5 16, 18, 20, 21, 24, 26 2.15 4.99 0.75 0.5 2.2
+6 16, 18, 20, 21, 24, 26 1.15 6.04 0.5 0.5 2.7
+9 17, 18, 20, 21, 24, 26 1.87 7.15 0.75 1 2.7
+12 17, 18, 20, 21, 24, 26 4.87 7.15 2 1 3
+15 17, 18, 20, 21, 24, 26 7.87 7.15 3.3 1 3
+28 17, 18, 20, 21, 24, 26 21 7.15 5.6 1 2
+45 22 3.57 48.7 2.2 10 39
+75 22 3.57 78.7 2.2 10 68
+100 22 3.57 102 2.2 10 91
+250 22 3.57 255 2.2 10 240
-6 (2) 18 3.57 2.43 1.2 0.5 0.75
-9 18 3.48 5.36 1.2 0.5 2
-12 18 3.57 8.45 1.2 0.5 3.3
-15 18 3.65 11.5 1.2 0.5 4.3
-28 18 3.57 24.3 1.2 0.5 10
-45 23 3.57 21.2 2.2 10 33
-100 23 3.57 97.6 2.2 10 91
-250 23 3.57 249 2.2 10 240
1. Replace R1/R2 divider with the circuit of Figure 27.
2. V+ must be connected to a +3 V or greater supply.
Table 7. Formula for intermediate output voltages
Conditions
Outputs from 2 to 7V
Figure 16, 19, 20, 21, 24, 26
VO=(VREFxR2)/(R1+R2)
Outputs from 4 to 250V
Figure 22
VO=(VREF/2)x[(R2-R1)/R1]; R3=R4
Current Limit
ILIMIT=VSENSE/RSC
Outputs from 7 to 37V
Figure 17, 19, 20, 21, 24, 26
VO=VREFx[(R1+R2)/R2]
Outputs from -6 to -250V
Figure 18, Figure 23
VO=(VREF/2)x[(R1+R2)/R1];
R3=R4
Foldback Current Limiting
IKNEE=[(VOxR3)/(RSCxR4)]x[VSENSEx(R3+R4)]
/ (RSCxR4)
ISHORTCKT=(VSENSE/RSC)x[(R3+R4)/R4]
Applications information LM723
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7 Applications information
Note: R3 = (R1xR2)/(R1+R2) for minimum temperature drift.
R3 may be eliminated for minimum component count.
Typical performance
Regulated output voltage..................5 V
Line regulation (
Δ
VI = 3 V)..........0.5 mV
Load regulation (
Δ
IO = 50 mA)...1.5 mV
Note: R3 = (R1xR2)/(R1+R2) for minimum temperature drift.
R3 may be eliminated for minimum component count.
Typical performance
Regulated output voltage..................15 V
Line regulation (
Δ
VI = 3 V)............1.5 mV
Load regulation (
Δ
IO = 50 mA).....4.5 mV
Figure 16. Basic low voltage regulator (VO = 2 to 7 V)
Figure 17. Basic high voltage regulator (VO = 7 to 37 V)
LM723 Applications information
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Note: Typical performance
Regulated output voltage.................15 V
Line regulation (
Δ
VI = 3 V)...............1 mV
Load regulation (
Δ
IO = 100 mA)......2 mV
Note: Typical performance
Regulated output voltage................15 V
Line regulation (
Δ
VI = 3 V)...........1.5 mV
Load regulation (
Δ
IO = 1 A)...........15 mV
Figure 18. Negative voltage regulator
Figure 19. Positive voltage regulator (external NPN pass transistor)
Applications information LM723
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Note: Typical performance
Regulated output voltage...................5 V
Line regulation (
Δ
VI = 3 V)...........0.5 mV
Load regulation (
Δ
IO = 1 A)..........1.5 mV
Note: Typical performance
Regulated output voltage....................5 V
Line regulation (
Δ
VI = 3 V)............0.5 mV
Load regulation (
Δ
IO = 10 mA)........1 mV
Current limit knee...........................20 mA
Figure 20. Positive voltage regulator (external PNP pass transistor)
Figure 21. Foldback current limiting
LM723 Applications information
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Note: Typical performance
Regulated output voltage....................100 V
Line regulation (
Δ
VI = 20 V)...............15 mV
Load regulation (
Δ
IO = 50 mA)..........20 mV
Note: Typical performance
Regulated output voltage....................-100 V
Line regulation (
Δ
VI = 20 V).................30 mV
Load regulation (
Δ
IO = 100 mA)..........20 mV
Figure 22. Positive floating regulator
Figure 23. Negative floating regulator
Applications information LM723
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Note: Typical performance
Regulated output voltage....................5 V
Line regulation (
Δ
VI = 30 V)...........10 mV
Load regulation (
Δ
IO = 2 A)............80 mV
Note: Current limit transistor may be used for shutdown if current limiting is not required.
Typical performance
Regulated output voltage...........................5 V
Line regulation (
Δ
VI = 3 V)...................0.5 mV
Load regulation (
Δ
IO = 50 mA)............1.5 mV
Figure 24. Positive switching regulator
Figure 25. Remote shutdown regulator with current limiting
LM723 Applications information
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Note: Typical performance
Regulated output voltage............................5 V
Line regulation (
Δ
VI = 10 V).....................2 mV
Load regulation (
Δ
IO = 100 mA)..............5 mV
Figure 26. Shunt regulator
Figure 27. Output voltage adjust
Package mechanical data LM723
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8 Package mechanical data
In order to meet environmental requirements, ST offers these devices in ECOPACK®
packages. These packages have a lead-free second level interconnect. The category of
second Level Interconnect is marked on the package and on the inner box label, in
compliance with JEDEC Standard JESD97. The maximum ratings related to soldering
conditions are also marked on the inner box label. ECOPACK is an ST trademark.
ECOPACK specifications are available at: www.st.com.
LM723 Package mechanical data
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Dim.
mm. inch.
Min. Typ. Max. Min. Typ. Max.
a1 0.51 0.020
B1.39 1.65 0.055 0.065
b0.5 0.020
b1 0.25 0.010
D200.787
E8.5 0.335
e 2.54 0.100
e315.24 0.600
F 7.1 0.280
I 5.1 0.201
L3.30.130
Z 1.27 2.54 0.050 0.100
Plastic DIP-14 mechanical data
P001A
Revision history LM723
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9 Revision history
Table 8. Document revision history
Date Revision Changes
21-Jun-2004 5
22-Nov-2007 6 Added Ta b l e 1 .
LM723
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