Shunt Regulator
LM431L LM431LA LM431LB
Shunt Regulator
General Description
TO-92
•
The LM431 Series ICs are low voltage three-terminal
programmable shunt regulators with guaranteed thermal
stability over a full operation range. These monolithic ICs
voltage reference operate as a low temperature coefficient
Zener which is programmable from Vref to 18V with two external
resistors. These devices exhibit a wide operating current range
SOT-23-5
of 80µA to 50/100mA with a typical dynamic impedance of 0.05 to
0.22Ω. The characteristics of these references make them excellent
replacements for Zener diodes in many applications such as
digital voltmeters, power supplies and op amp circuitry
•
The LM431L precision reference is offered in three voltage
tolerance for V
REF
=1.240V: 1.5%, 1.0% and 0.5%.
•
These ICs are available in 4 packages: TO-92, SOT-23, SOT-23-5 and SOT-89.
.
.
SOT-23
SOT-89
Features
•
Programmable Precise Output Voltage from
1.24V to 16/18V
•
High Stability under Capacitive Load
•
Low Temperature Deviation
•
•
•
•
Low Dynamic Output Impedance: 0.05 to 0.22Ω Typical
Operating Current from 80µA to 50/100mA.
Low Output Noise Voltage
RoHS Compliance
Applications
•
•
•
•
•
Graphic Card
PC Motherboard
Voltage Adapter
Switching Power Supply
Charger
TAITRON COMPONENTS INCORPORATED
www.taitroncomponents.com
Tel:
Fax:
(800)-TAITRON (800)-824-8766
(800)-TAITFAX (800)-824-8329
(661)-257-6060
(661)-257-6415
Rev. A/DX 2007-06-04
Page 1 of 13
Shunt Regulator
LM431L
Block Diagram
Symbols
Absolute Maximum Ratings (Ta=25° C)
(Full operating ambient temperature range applies unless otherwise noted.)
Symbol
V
KA
I
KA
I
REF
T
J
T
OPR
T
STG
Description
Cathode Voltage
Cathode Current Range (Continuous)
Reference Input Current Range
(Continuous)
Operating Junction Temperature
Operating Temperature Range
Storage Temperature Range
Z:TO-92
P
D
Power Dissipation
N:SOT-23
N5:SOT-23-5
K: SOT-89
Z:TO-92
Rth
JA
Package Thermal
Impedance
N:SOT-23
N5:SOT-23-5
K: SOT-89
700
350
550
-
180
360
230
-
LM431L
16
50
3
150
-40 ~ 85
-40 ~ 125
-65 ~ 150
770
370
370
770
150
330
250
50
° C/W
mW
LM431LA
LM431LB
Unit
V
mA
mA
°C
°C
°C
18
-100 ~ +100
10
Rev. A/DX 2007-06-04
www.taitroncomponents.com
Page 3 of 13
Shunt Regulator
LM431L
Electrical Characteristics
(T
A
=25ºC, unless otherwise specified)
Symbol
V
REF
Description
Reference Input
Voltage
Reference
Input
Voltage
Deviation
0-70° C
LM431L
Min.
1.222
-
-
-
Typ.
1.240
-
7.0
-
Max.
1.258
-
20
-
LM431LA
Min.
1.228
-
-
-
Typ.
1.240
2
3
4
Max.
1.252
1-
10
15
LM431LB
Min.
1.234
-
-
-
Typ.
1.240
2
3
4
Max.
1.246
10
10
15
Unit
V
Test
Circuit
Fig.1
Conditions
V
KA
=V
REF
,I
KA
=10mA
∆V
REF
∆V
REF/
∆V
KA
I
REF
∆I
REF
-40-85
°C
-40-125
°C
Ratio of Change in
Reference Input
Voltage to Change in
Cathode to Anode
Voltage
Reference
Ta=25°
Input
C
Current
Reference Input
Current Deviation
Over Temperature
Range
Min. Cathode Current
For Regulation
mV
Fig.1
(Note1)
V
KA
=V
REF
,I
KA
=10mA
-
-0.6
-1.5
-
-0.5
-1.5
-
-0.5
-1.5
mV/V
Fig.2
IKA=
10mA
∆V
KA
=
V
KA(max)
~V
REF
-
0.15
0.3
-
0.15
0.4
-
0.15
0.4
µA
Fig.2
I
KA
=10mA, R1=10KΩ,
R2=∞
I
KA
=10mA, R1=10KΩ,
R2=∞
-
0.05
0.08
-
0.1
0.4
-
0.1
0.4
µA
Fig.2
I
MIN
-
55
80
-
55
80
-
55
80
µA
Fig.1
V
KA
=V
REF
V
KA
= V
KA(max)
,
V
REF
=0V
V
KA
=6V, V
REF
=0V
I
OFF
Off-State Cathode
Current
-
-
-
2.6
-
0.22
1000
-
0.4
-
-
-
40
10
0.05
100
50
0.15
-
-
-
40
10
0.05
100
nA
50
0.15
Ω
Fig.1
(Note2)
Fig.3
Z
KA
Dynamic Impedance
V
KA
=V
REF
,
I
KA
=1.0mA~ I
KA(max)
,
f≤1.0KHz
Fig.1- Test Circuit for V
KA
=V
REF
Fig.2- Test Circuit for V
KA
>V
REF
Rev. A/DX 2007-06-04
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Page 4 of 13
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