© Semiconductor Components Industries, LLC, 2003
April, 2021 − Rev. 3
1 Publication Order Number:
LM431A/D
Programmable Shunt
Regulator
LM431A, LM431B, LM431C
Description
The LM431A/LM431B/LM431C are three−terminal output
adjustable regulators with thermal stability over the full operating
temperature range. The output voltage can be set to any value between
V
REF
(approximately 2.5 V) and 36 V with two external resistors.
These devices have a typical dynamic output impedance of 0.2 W.
Active output circuit provides a sharp turn−on characteristic, making
these devices excellent replacements for Zener diodes in many
applications.
Features
• Programmable Output Voltage to 36 V
• Low Dynamic Output Impedance: 0.2 W (Typical)
• Sink Current Capability: 1.0 to 100 mA
• Equivalent Full−Range Temperature Coefficient of 50 ppm/°C
(Typical)
• Temperature Compensated for Operation Over Full Rated
Operating Temperature Range
• Low Output Noise Voltage
• Fast Turn−on Response
Figure 1. Block Diagram
TO−92
CASE 135AN
www.onsemi.com
See detailed ordering and shipping information in the package
dimensions section on page 6 of this data sheet.
ORDERING INFORMATION
MARKING DIAGRAM
PIN CONNECTIONS
LM431
XXXX
ALYW
LM431XXXX = Specific Device Code
A = Assembly Location
L = Wafer Lot
YW = Assembly Start Week
1
2
3
1
2
3
TO−92
CASE 135AR
123
1 − Ref
2 − Anode
3 − Cathode
123
LM431A, LM431B, LM431C
www.onsemi.com
2
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
KA
Cathode Voltage 37 V
I
KA
Cathode Current Range (Continuous) −100 to +150 mA
I
REF
Reference Input Current Range −0.05 to +10 mA
P
D
Power Dissipation 770 mW
R
θ
jA
Thermal Resistance, Junction to Ambient 160 °C/W
T
OPR
Operating Temperature Range − LM431xC −25 to +85 °C
Operating Temperature Range − LM431xI −40 to +85 °C
T
J
Junction Temperature 150 °C
T
STG
Storage Temperature Range −65 to +150 °C
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality
should not be assumed, damage may occur and reliability may be affected.
RECOMMENDED OPERATING CONDITIONS
Symbol Parameter Min Max Unit
V
KA
Cathode Voltage V
REF
36 V
I
KA
Cathode Current 1.0 100 mA
Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond
the Recommended Operating Ranges limits may affect device reliability.
ELECTRICAL CHARACTERISTICS (Values are at T
A
= 25°C unless otherwise noted)
Symbol
Parameter Conditions
LM431A LM431B LM431C
Unit
Min Typ Max Min Typ Max Min Typ Max
V
REF
Reference Input
Voltage
V
KA
= V
REF
, I
KA
= 10 mA 2.450 2.500 2.550 2.470 2.495 2.520 2.482 2.495 2.508 V
DV
REF
/DT
Deviation of
Reference Input
Voltage Over−
Temperature
V
KA
= V
REF
, I
KA
=10 mA
T
MIN
≤ T
A
≤ T
MAX
(Note 1)
− 4.5 17.0 − 4.5 17.0 − 4.5 17.0 mV
DV
REF
/
DV
KA
Ratio of Change in
Reference Input
Voltage to the
Change in Cathode
Voltage
I
KA
= 10 mA
DV
KA
=
10 V−V
REF
− −1.0 −2.7 − −1.0 −2.7 − −1.0 −2.7
mV/V
DV
KA
=
36 V−10 V
− −0.5 −2.0 − −0.5 −2.0 − −0.5 −2.0
I
REF
Reference Input
Current
I
KA
= 10 mA, R1 = 10 kW,
R2 = ∞
− 1.5 4.0 − 1.5 4.0 − 1.5 4.0
mA
DI
REF
/DT
Deviation of
Reference Input
Current Over Full
Temperature Range
I
KA
= 10 mA, R1 = 10 kW,
R2 = ∞, T
A
= Full Range
− 0.4 1.2 − 0.4 1.2 − 0.4 1.2
mA
I
KA(MIN)
Minimum Cathode
Current for
Regulation
V
KA
= V
REF
− 0.45 1.00 − 0.45 1.00 − 0.45 1.00 mA
I
KA(OFF)
Off − Stage
Cathode Current
V
KA
= 36 V, V
REF
= 0 −
0.05 1.00
−
0.05 1.00
−
0.05 1.00
mA
Z
KA
Dynamic
Impedance
V
KA
= V
REF
, I
KA
= 1 to 100
mA,
f ≥ 1.0 kHz
−
0.15 0.50
−
0.15 0.50
−
0.15 0.50
W
Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product
performance may not be indicated by the Electrical Characteristics if operated under different conditions.
1. LM431xC: T
MIN
= −25°C, T
MAX
= +85°C
LM431xI: T
MIN
= −40°C, T
MAX
= +85°C