FAIRCHILD LM431B

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LM431A/LM431B/LM431C
Programmable Shunt Regulator
Features
Description
•
•
•
•
The LM431A/LM431B/LM431C are three terminal output
adjustable regulators with thermal stability over operating
temperature range. The output voltage can be set any value
between VREF (approximately 2.5 volts) and 36 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.
Programmable Output Voltage to 36 Volts
Low Dynamic Output Impedance 0.20 Typical
Sink Current 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
TO-92
1
1. Ref 2. Anode 3. Cathode
8-DIP
8-SOP
1
1
1.Cathode 2.3.4.5.7.NC
6.Anode 8.Ref
1.Cathode 2.3.6.7.Anode
4.5.NC 8.Ref
Internal Block Diagram
CATHODE
REFERENCE
2.5 Vref
ANODE
CATHODE (K)
REFERENCE (R)
ANODE (A)
Rev. 1.0.7
©2003 Fairchild Semiconductor Corporation
LM431A/LM431B/LM431C
Absolute Maximum Ratings
(Operating temperature range applies unless otherwise specified.)
Parameter
Symbol
Value
Unit
Cathode Voltage
VKA
37
V
Cathode Current Range (Continuous)
IKA
-100 ~ +150
mA
IREF
-0.05 ~ +10
mA
PD
770
1000
mW
-25 ~ +85
°C
Reference Input Current Range
Power Dissipation
M, Z Suffix Package
N Suffix Package
Operating Temperature Range
LM431xC
TOPR
LM431xI
-40 ~ +85
°C
TJ
150
°C
TSTG
-65 ~ +150
°C
Junction Temperature
Storage Temperature Range
Recommended Operating Conditions
Parameter
2
Symbol
Min
Typ
Max
Unit
Cathode Voltage
VKA
VREF
-
36
V
Cathode Current
IKA
1.0
-
100
mA
LM431A/LM431B/LM431C
Electrical Characteristics
(TA = +25°C, unless otherwise specified)
Parameter
Symbol
Conditions
Reference
Input Voltage
VREF
VKA = VREF, IKA =10mA
Deviation of
Reference
Input Voltage
OverTemperature
∆VREF/
∆T
VKA=VREF, IKA=10mA
TMIN≤TA≤TMAX
LM431A
LM431B
Min. Typ. Max. Min. Typ. Max. Min. Typ. Max.
2.450 2.500 2.550 2.470 2.495 2.520 2.482 2.495 2.508
-
4.5
17
-
-1.0
-2.7
-
-0.5
IKA=10mA,
R1=10kΩ,R2=∞
-
Deviation of
Reference
Input Current
Over Full
Temperature
Range
IKA=10mA,
R1=10kΩ,R2=∞
∆IREF/∆T
TA =Full Range
-
Minimum
Cathode Current for
Regulation
IKA(MIN)
VKA=VREF
Off - Stage
Cathode
Current
IKA(OFF)
∆VREF/
∆VKA
Reference
Input Current
IREF
Dynamic
Impedance
17
-
-1.0
-2.7
-2.0
-
-0.5
1.5
4
-
0.4
1.2
-
0.45
1.0
VKA=36V,
VREF=0
-
0.05
VKA=VREF,
IKA=1 to 100mA
f ≥1.0kHz
-
0.15
IKA
=10mA
∆VKA=36V10V
ZKA
-
4.5
∆VKA=10VVREF
Ratio of
Change in
Reference
Input Voltage
to the Change
in Cathode
Voltage
LM431C
-
Unit
V
4.5
17
mV
-
-1.0
-2.7
-2.0
-
-0.5
-2.0
1.5
4
-
1.5
4
µA
0.4
1.2
0.4
1.2
µA
-
0.45
1.0
-
0.45
1.0
mA
1.0
-
0.05
1.0
-
0.05
1.0
µA
0.5
-
0.15
0.5
-
0.15
0.5
Ω
mV/V
-
-
Note1
• LM431XC : TMIN = -25 °C, TMAX = +85°C
• LM431XI : TMIN = -40°C, TMAX = +85°C
3
LM431A/LM431B/LM431C
Test Circuits
LM431A/B/C
LM431A/B/C
Figure 1. Test Circuit for VKA=VREF
LM431A/B/C
Figure 3. Test Circuit for lKA(OFF)
4
Figure 2. Test Circuit for VKA≥VREF
LM431A/LM431B/LM431C
Typical Performance Characteristics
Figure 4. Cathode Current vs. Cathode Voltage
Figure 6. Change In Reference Input Voltage vs.
Cathode Voltage
Figure 8. Small Signal Voltage Amplification vs. Frequency
Figure 5. Cathode Current vs. Cathode Voltage
Figure7. Dynamic Impedance Frequency
Figure 9. Pulse Response
5
LM431A/LM431B/LM431C
Typical Performance Characteristics (Continued)
140
A
IK, CATHODE CURRENT(mA)
120
100
A VKA = Vref
B VKA = 5.0 V @ IK = 10mA
C VKA = 10 V @ IK = 10mA
D VKA = 15 V @ IK = 10mA
B
C
o
TA = 25 C
80
60
40
D
20
0
100p
1n
10n
100n
1!
CL, LOAD CAPACITANCE
Figure 10. Stability Boundary Conditions
6
10!
LM431A/LM431B/LM431C
Typical Application
R
V O = V ref  1 + ------1-

R 2
R
V O =  1 + ------1- V ref

R 
2
R
V O =  1 + ------1- V ref

R 
2
LM7805/MC7805
LM431A/B/C
LM431A/B/C
LM431A/B/C
Figure 12. Output Control for
Three--Te r- minal Fixed Regulator
Figure 11. Shunt Regulator
LM431A/B/C
Figure 14. Current Limit or Current Source
Figure 13. High Current Shunt Regulator
LM431A/B/C
Figure 15. Constant-Current Sink
7
LM431A/LM431B/LM431C
Mechanical Dimensions
Package
Dimensions in millimeters
TO-92
+0.25
4.58 ±0.20
4.58 –0.15
14.47 ±0.40
0.46 ±0.10
1.27TYP
[1.27 ±0.20]
1.27TYP
[1.27 ±0.20]
8
(0.25)
+0.10
0.38 –0.05
1.02 ±0.10
3.86MAX
3.60 ±0.20
(R2.29)
+0.10
0.38 –0.05
LM431A/LM431B/LM431C
Mechanical Dimensions (Continued)
Package
Dimensions in millimeters
8-SOP
MIN
#5
1.80
MAX
0.071
3.95 ±0.20
0.156 ±0.008
5.72
0.225
0~
8°
+0.10
0.15 -0.05
+0.004
0.006 -0.002
MAX0.10
MAX0.004
6.00 ±0.30
0.236 ±0.012
0.41 ±0.10
0.016 ±0.004
#4
1.27
0.050
#8
5.13
MAX
0.202
#1
4.92 ±0.20
0.194 ±0.008
(
0.56
)
0.022
1.55 ±0.20
0.061 ±0.008
0.1~0.25
0.004~0.001
0.50 ±0.20
0.020 ±0.008
9
LM431A/LM431B/LM431C
Mechanical Dimensions (Continued)
Package
Dimensions in millimeters
#5
1.524 ±0.10
0.060 ±0.004
#4
0.018 ±0.004
#8
2.54
0.100
9.60
MAX
0.378
#1
9.20 ±0.20
0.362 ±0.008
(
6.40 ±0.20
0.252 ±0.008
0.46 ±0.10
0.79
)
0.031
8-DIP
5.08
MAX
0.200
7.62
0.300
3.40 ±0.20
0.134 ±0.008
+0.10
0.25 –0.05
+0.004
0~15°
10
0.010 –0.002
3.30 ±0.30
0.130 ±0.012
0.33
0.013 MIN
LM431A/LM431B/LM431C
Ordering Information
Product Number
LM431CCZ
LM431CCM
LM431BCZ
LM431BCM
Output Voltage Tolerance
0.5%
1%
LM431ACN
LM431ACZ
LM431CIZ
LM431BIZ
LM431BIM
LM431AIZ
LM431AIM
Operating Temperature
TO-92
8-SOP
TO-92
8-SOP
-25 ~ +85°C
8-DIP
2%
LM431ACM
LM431CIM
Package
TO-92
8-SOP
0.5%
1%
2%
TO-92
8-SOP
TO-92
8-SOP
-40 ~ +85°C
TO-92
8-SOP
11
LM431A/LM431B/LM431C
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY
PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY
LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER
DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and (c) whose failure to
perform when properly used in accordance with
instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.
2. A critical component in any component of a life support
device or system whose failure to perform can be
reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
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