Fairchild Semiconductor LM431SC, LM431SB, LM431SA Datasheet
LM431SA/LM431SB/LM431SC
Programmable Shunt Regulator
www.fairchildsemi.com
Features
• Programmable Output Voltage to 36 Volts
• Low Dynamic Output Impedance 0.20 Typical
• Sink Curren t Capability of 1.0 to 100mA
• Equivalent Full-Range Temperature Coefficient of
50ppm/°C Typical
• Temperature Compensated for Operation Over Full Rated
Operating Temperature Range
• Low Output Noise Voltage
• Fast Turn-on Response
Description
The LM431SA/LM431SB/LM431SC are three terminal
output adjustable regulators with thermal stability over
operating temperature range. The output voltage can be set
any value between V
volts with two external resistors. These devices have a
typical dynamic output impedance of 0.2Ω Active output
circuit provides a sharp turn-on characteristic, making these
devices excellent replacement for Zener Diodes in many
applications.
SOT-89
1
1. Ref 2. Anode 3. Cathode
SOT-23F
3
2
1
1. Cathode 2. Ref 3. Anode
(approximat ely 2.5 volts) and 36
REF
Internal Block Diagram
©2002 Fairchild Semiconductor Corporation
Rev. 1.0.3
LM431SA/LM431SB/LM431SC
Absolute Maximum Ratings
(Operating temperature range applies unless otherwise specified.)
Parameter Symbol Value Unit
Cathode Voltage V
Cathode current Range (Continuous) I
Reference Input Current Range I
Thermal Resistance Junction-Air (Note1,2)
MF Suffix Package
ML Suffix Package
Power Dissipation (Note3,4)
MF Suffix Package
ML Suffix Package
Junction Temperature T
Operating Temperature Range T
Storage Temperature Range T
Note:
1. Thermal resistance test board
Size: 76.2mm * 114.3mm * 1.6mm (1S0P)
JEDEC Standard: JESD51-3, JESD51-7
2. Assume no ambient airflow.
3. T
JMAX
4. Power dissipation calculation: PD = (TJ - TA)/
= 150
°
, Ratings apply to ambient temperature at 25
C
R
θJA
REF
R
P
OPR
STG
°
C
KA
KA
θJA
D
J
37 V
-100 ~ +150 mA
0.05 ~ +10 mA
350
°C/W
220
350
560
150 °C
-25 ~ +85 °C
-65 ~ +150 °C
mW
Recommended Operating Conditions
Parameter Symbol Min. Typ. Max. Unit
Cathode Voltage V
Cathode Current I
KA
KA
V
REF
1.0 - 100 mA
-36V
2
Electrical Characteristics
(TA = +25°C, unless otherwise specified)
LM431SA/LM431SB/LM431SC
Parameter Symbol Conditions
Reference
Input Voltage
Deviation of
Reference
Input Voltage
OverTemperature
Ratio of
Change in
Reference
Input Voltage
to the Change
in Cathode
Voltage
Reference
Input Current
Deviation of
Reference
Input Current
Over Full
Temperature
Range
Minimum
Cathode
Current for
Regulation
Off -Stage
Cathode
Current
Dynamic
Impedance
V
REF
V
∆
∆
V
∆
V
∆
I
REF
I
∆
REF
I
KA(MIN)VKA=VREF
I
KA(OFF)VKA
Z
REF
T
REF
KA
KA
/
/
/∆T
VKA=V
V
KA=VREF
T
MIN≤TA≤TMAX
IKA
=10mA
IKA=10mA,
=10KΩ,R2=∞
R
1
I
=10mA,
KA
=10KΩ,R2=∞
R
1
T
=Full Range
A
=36V, V
VKA=V
I
=1 to 100mA ,f ≥1.0kHz
KA
, IKA=10mA 2.450 2.500 2.550 2.470 2.495 2.520 2.482 2.495 2.508 V
REF
, IKA=10mA
∆
VKA=10V-
V
REF
VKA=36V-
∆
10V
=0 - 0.05 1.0 - 0.05 1.0 - 0.05 1.0
REF
,
REF
LM431SA LM431SB LM431SC
Min. Typ. Max. Min. Typ. Max. Min. Typ. Max.
-
4.5 17
- -1.0 -2.7 - -1.0 -2.7 - -1.0 -2.7
- -0.5 -2.0 - -0.5 -2.0 - -0.5 -2.0
-1.54 -1.54 -1.54
-
0.4 1.2
- 0.45 1.0 - 0.45 1.0 - 0.45 1.0 mA
- 0.15 0.5 - 0.15 0.5 - 0.15 0.5 Ω
-
-
4.5 17
0.4 1.2
-
4.5 17 mV
-
0.4 1.2
Unit
mV/V
A
µ
A
µ
A
µ
Note1
T
MIN
= -25°C, T
MAX
= +85°C
3
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