Datasheet LM431B, LM431A, LM431C Datasheet (Fairchild Semiconductor)

LM431A/LM431B/LM431C

Programmable Shunt Regulator

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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 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 V
two external resistors. These devices have a typical dynamic
output imped ance of 0.2Ω Act ive output circ uit provides a
sharp turn-on characteristic, making these devices excellent
replacement for Zener Diodes in many applications.

TO-92

1

1. Ref 2. Anode 3. Cathode

8-DIP 8-SOP

1.Cathode 2.3 .4.5.7.NC

6.Anode 8.Ref

(approximately 2.5 volts) and 36 volts with

REF

1

1.Cathode 2.3.6.7.A no de

4.5.NC 8.Ref

1

Internal Block Diagram

REFERENCE

REFERENCE (R)

©2002 Fairchild Semiconductor Corporation

CATHODE

2.5 Vref

ANODE

CA THODE (K)

ANODE (A)

Rev. 1.0.6

LM431A/LM431B/LM431C

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

KA

KA

REF

37 V

-100 ~ +150 mA

0.05 ~ +10 mA

Power Dissipation
M, Z Suffix Package
N Suffix Package

P

D

770

mW

1000

Operating Temperature Range

LM431xC
LM431xI -40 ~ +85 °C
Junction Temperature T
Storage Temperature Range T

T

OPR

J

STG

-25 ~ +85 °C

150 °C

-65 ~ +150 °C

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)

LM431A/LM431B/LM431C

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 Z

V

REF

V

∆

∆

V

∆

V

∆

I

REF

I

∆

REF

I

KA(MIN)VKA=VREF

I

KA(OFF)

REF

T

REF

KA

/

/

/∆T

V

= V

KA

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

VKA=36V,
V

=0

REF

VKA=V

KA

KA

=1 to 100mA

I
f ≥1.0kHz

, I

REF

, IKA=10mA

∆

V

∆

10V

,

REF

KA

VKA=10V-

REF

VKA=36V-

LM431A LM431B LM431C

Min. Typ. Max. Min. Typ. Max. Min. Typ. Max.

Unit

=10mA 2.450 2.500 2.550 2.470 2.495 2.520 2.482 2.495 2.508 V

-

4.5 17

-

4.5 17

-

4.5 17 mV

- -1.0 -2.7 - -1.0 -2.7 - -1.0 -2.7

mV/V

- -0.5 -2.0 - -0.5 -2.0 - -0.5 -2.0

-1.54 -1.54 -1.54

-

0.4 1.2

-

0.4 1.2

-

0.4 1.2

µ

µ

- 0.45 1.0 - 0.45 1.0 - 0.45 1.0 mA

- 0.05 1.0 - 0.05 1.0 - 0.05 1.0

µ

- 0.15 0.5 - 0.15 0.5 - 0.15 0.5 Ω

A

A

A

Note1

•LM431

•LM431

C : T

X

I : T

X

MIN

MIN

= -25 °C, T

= -40°C, T

MAX

MAX

= +85°C

= +85°C

3

LM431A/LM431B/LM431C

Test Circuits

LM431A/B/C

LM431A/B/C

Figure 1. Test Circuit for VKA=V

LM431A/B/C

Figure 3. Test Circuit for l

KA(OFF)

REF

Figure 2. Test Circuit for V

KA

≥≥≥≥V

REF

4

Typical Performance Characteristic s

LM431A/LM431B/LM431C

Figure 6.

Figure 4.

Cathode Current vs. Cathode Voltage

Change In Reference Input Voltage vs.

Cathode Voltage

Figure 5.

Cathode Current vs. Cathode Voltage

Figure7. Dynamic Impedance Frequency

Figure 8. Small Signal Voltage Amplification vs. Frequency

Figure 9.

Pulse Response

5

LM431A/LM431B/LM431C

Typical Performance Characte ristic s

140

A VKA = Vref

120

100

80

60

40

, CATHODE CURRENT(mA)

K

I

20

0
100p 1n 10n 100n 1µ 10µ

= 5.0 V @ IK = 10

B V

KA

C VKA = 10 V @ IK = 10
D VKA = 15 V @ IK = 10

TA = 25oC

CL, LOAD CAPACITANCE

Figure 10. Stability Boundary Conditions

A

mA
mA
mA

B

C

D

(Continued)

6

Typical Application

LM431A/LM431B/LM431C

R

1



V

1

------ -+

=

O



Figure 11. Shunt Regulator

V

ref

R

2

LM431A/B/C

Figure 12

LM431A/B/C

Figure 14. Current Limit or Current Source

VOV

=

LM7805/MC7805

LM431A/B/C

.

Output Control for

-

minal Fixed RegulatorThree- Ter-

R

1



1

------ -+

ref



R

2

R



V

1

------ -+

=

O



R

Figure 13. High Current Shunt Regulator

LM431A/B/C

Figure 15. Constant-Current Sink

1

V

ref

2

LM431A/B/C

7

LM431A/LM431B/LM431C

Mechanical Dimensions

Package

Dimensions in millimeters

0.46

±0.10

4.58

+0.25
–0.15

TO-92

±0.20

4.58

±0.40

14.47

1.27TYP

[1.27

±0.20

1.27TYP

]

3.60

±0.20

[1.27

±0.20

]

0.38

+0.10
–0.05

3.86MAX
(0.25)

+0.10

±0.10

1.02

–0.05

0.38

(R2.29)

8

LM431A/LM431B/LM431C

Mechanical Dimensions

Package

#1

#4

(Continued)

8-SOP

1.55

±0.20

0.061

#8

MAX

5.13

#5

±0.008

0.202

Dimensions in millimeters

0.1~0.25

MIN

0.004~0.001

0.56

0.022

()

±0.008

±0.20

4.92

0.194

±0.10

±0.004

0.006

-0.002

0.50

0.020

+

0.004

±0.20

±0.008

0.15

-0.05

+

0.10

6.00

0.236

3.95

0.156

5.72

0.225

±0.30

±0.012

±0.20

±0.008

0.071

0~8°

1.80
MAX

MAX0.10

MAX0.004

1.27

0.050

0.41

0.016

9

LM431A/LM431B/LM431C

Mechanical Dimensions

Package

6.40

±0.20

±0.008

0.252

#1

#4 #5

#8

(Continued)

MAX

9.60

0.378

8-DIP

±0.008

±0.20

9.20

0.362

Dimensions in millimeters

0.79

0.031

()

±0.10

0.46

2.54

±0.004

0.018

0.100

±0.10

±0.004

1.524

0.060

0~15°

7.62

0.300

0.25

0.010

5.08

0.200

3.40

0.134

+0.10
–0.05

+0.004
–0.002

MAX

±0.20

±0.008

0.33

0.013

MIN

3.30

0.130

±0.30
±0.012

10

Ordering Information

Product Number Output Voltage Tolerance Package Operating Temperature

LM431CCZ
LM431CCM 8-SOP
LM431BCZ

LM431BCM 8-SOP

0.5%

1%

LM431ACN

LM431ACZ TO-92

2%

LM431ACM 8-SOP

LM431CIZ
LM431CIM 8-SOP
LM431BIZ

LM431BIM 8-SOP

LM431AIZ
LM431AIM 8-SOP

0.5%

1%

2%

TO-92

TO-92

8-DIP

TO-92

TO-92

TO-92

-25 ~ +85

-40 ~ +85

LM431A/LM431B/LM431C

°

C

°

C

11

LM431A/LM431B/LM431C

DISCLAIMER

FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURT HER NOTICE TO ANY
PRODUCTS HEREI N TO IMPROVE RELIABILITY, FUNCTIO N OR DESIGN. FAIRCH IL D 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 IT S PATENT RIGHTS, NOR THE RIGHTS OF OTHE RS.

LIFE SUPPORT POL I CY

FAIRCHILD’S PR ODUCTS ARE NOT AUTH ORIZED FOR USE AS C RITICAL COMPONENT S IN LIFE SUPPORT DE VICES
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

2. A critical component in any component of a life support
device or sy stem whose fai lure to perform can be
reasonably expec ted to cause the failur e of the life support
device or system, or to affect its safety or effec t iv ene ss .

instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.

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8/20/02 0.0m 001

 2002 Fairchild Semiconductor Corporation

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