Diodes TL432 User Manual

5

3

Description

TL431/TL432

ADJUSTABLE PRECISION SHUNT REGULATOR

Pin Assignments

The TL431 and TL432 are three terminal adjustabl e shunt
regulators offering excellent temperature stability and output
current handling capability up to 100mA. The output voltage
may be set to any chosen voltage between 2.5 and 36 volt s
by selection of two external divider resistors.

The devices can be used as a replacement for zener diodes
in many applications requiring an improvement in zener
performance. Diodes’ TL431 has the same electrical
specifications as the industry standard ‘431 and is available
in 2 grades with initial tolerances of 1% and 0.5% for the
A and B grades respectively.

Features

• Temperature range -40 to +125ºC

• Reference Voltage Tolerance at 25°C

• TL431A: 2.495V ± 1.0%

• TL431B: 2.495V ± 0.5%

• Low Output Noise

• 0.2Ω Typical Output Impedance

• Sink Current Capability: 1mA to 100mA

• Adjustable Output Voltage: V

• All devices are:

• Totally Lead-Free & Fully RoHS compliant

(Notes 1 & 2)

• Halogen and Antimony Free. “Green” Device
(Note 3)

REF

to 36V

Applications

• Opto-Coupler Linearisers

• Shunt Regulators

• Improved Zener

• Variable Reference

CATHODE

REF

NC

Leave floating or

connect to pin 5

CATHODE

CATHODE

ANODE
ANODE

NC

SO-8 is a future product

REF

CATHODE

TL431

(Top View)

1

2

SOT23

(Top View)

2

3

SOT2

(Top View)

1
2
3
4

SO-8

TL432

(Top View)

1

2

ANODE

3

5

4

3

ANODE

REF

REF

8

ANODE

7
6

ANODE

5

NC

ANODE

SOT2

Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.

2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen and Antimony free,
"Green" and Lead-Free.

3. Halogen and Antimony free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.

TL431 *SO-8 is a future package

Document number: DS35044 Rev. 6 - 2

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TL431/TL432

Absolute Maximum Ratings (Note 4)

Symbol Parameter Rating Unit

VKA

IKA

I

REF

TJ

TST

PD

Notes: 4. Operation above the absolute maximum rating may cause device failure. Operation at the absolute maximum ratings, for extended periods, may
reduce device reliability. Unless otherwise stated voltages specified are relative to the ANODE pin.

5. T

6. Ratings apply to ambient temperature at 25°C.

Recommended Operating Conditions

Symbol Parameter Min Max Unit

VKA

IKA
TA

TL431 *SO-8 is a future package

Document number: DS35044 Rev. 6 - 2

Cathode Voltage 40 V
Continuous Cathode Current 150 mA

Reference Input Current -0.050 to +10 mA
Operating Junction Temperature +150
Storage Temperature -55 to +150

Power Dissipation (Notes 5, 6)

=150°C.

J, MAX

Cathode Voltage
Cathode Current 1 100 mA
Operating Ambient Temperature -40 +125 °C

ADJUSTABLE PRECISION SHUNT REGULATOR

°

C

°

C
SOT23 330
SOT25 500
SO-8* 700

V

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REF

36 V

mW

April 2012

© Diodes Incorporated

TL431/TL432

Electrical Characteristics (T

Symbol Parameter Test Conditions Min Typ. Max Unit

V

Reference voltage

REF

V

ΔV

ΔV

Deviation of reference voltage over

DEV

full temperature range (Note 5)

Ratio of the change in reference

REF

voltage to the change in cathode

KA

voltage

I

REF

ΔI

I

KA(MIN)

I

KA(OFF)

|ZKA|

θ

Notes: 7. Deviation of V

The average temperature coefficient of the reference input voltage αV

Where:
T2 – T1 = full temperature change.

αV
positive or negative.

Notes: 8. The dynamic output impedance, R

When the device is programmed with two external resistors R1 and R2, the dynamic output
impedance of the overall circuit, is defined as:

Reference input current

I

deviation over full temperature

REF

REF

range (Note 7)

Minimum cathode current for
regulation

Off-state current
Dynamic output impedance (Note 8)

Thermal Resistance Junction to

JA

Ambient

, and ΔI

DEV

can be positive or negative depending on whether the slope is

REF

Z’

Z’

Z’

=

=

=

are defined as the maximum variation of the values over the full temperature range.

REF

αV

αV

=

=

REF

REF

ΔV

ΔV

ΔV

ΔI

ΔI

ΔI

TL431 *SO-8 is a future package

Document number: DS35044 Rev. 6 - 2

= +25°C, unless otherwise noted)

A

V

V

DEV

DEV

V

@ 25ºC

V

@ 25ºC

REF

REF

T2 – T1

T2 – T1

Z

ΔV

ΔV

Z

Z

=

=

KA

KA

Z

Z

Z

≈

≈

KA

KA

KA

X 10

X 10

, is defined as:

KA

KA

ΔI

ΔI

KA

KA

R1

R1

R1

1 +

1 +

1 +

R2

R2

R2

ADJUSTABLE PRECISION SHUNT REGULATOR

V

= V

KA

REF

I

= 10mA

KA

VKA = V
I

I

I
I

REF

= 10mA

KA

= 10mA

KA

= 10mA, R1 = 10KΩ, R2 = ∞

KA

= 10mA,

KA

R1 = 10KΩ,
R2 = ∞

VKA = V

REF

VKA = 36V, V
VKA = V

REF,

SOT23 380

SO-8* 70

6

6

ppm/ºC

ppm/ºC

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TL431A 2.470 2.495 2.520

,

TL431B 2.482 2.495 2.507

= 0 to 70oC

T

,

A

TA = -40 to +85oC
TA = -40 to +125oC
V

KA

VKA = 36V to 10V

= 10V to V

REF

6 16
14 34
14 34

-1.4 -2.7

-1 -2
1 4 µA

= 0 to 70oC

T

A

TA = -40 to +85oC
TA = -40 to +125oC

= 0V

REF

f = 0Hz

is defined as:

REF

Vmax

Vmax

Vmin

Vmin

0.8 1.2

0.8 2.5

0.8 2.5

0.4 0.7 mA

0.05 0.5 µA

0.2 0.5 Ω

V

V

= Vmax - Vmin

= Vmax - Vmin

DEV

DEV

T1 T2

T1 T2

Temperature

Temperature

© Diodes Incorporated

April 2012

V

mV

mV/V

µA

o

C/W SOT25 250

Test Circuits

ADJUSTABLE PRECISION SHUNT REGULATOR

Figure 1. Test circuit for VKA = V

TL431/TL432

REF

TL431 *SO-8 is a future package

Document number: DS35044 Rev. 6 - 2

Figure 2. Test circuit for VKA > V

Figure 3. Test circuit for I

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OFF

REF

April 2012

© Diodes Incorporated

2

0

Typical Performance Characteristics

2600
2580

2560
2540
2520

I = 10mA

KA

V = V

KA REF

T = 25C

A

TL431/TL432

ADJUSTABLE PRECISION SHUNT REGULATOR

0.

R1 = 10K

Ω

R2 =

°

0.15

μ

∞

I = 10mA

KA

2500
2480
2460

REF

V Reference Voltage (mV)

2440
2420
2400

-55 -35 -15 5 25 45 65 85 105 125
T Free Air Temperature ( C)

A

Reference Voltage vs. Free Air Temperature

150

V = V

KA REF

T = 25C

°

A

100

50

0

KA

I Cathode Current (mA)

-50

0.1

REF

0.05

I Reference Current ( A)

0

-55 -35 -15 5 25 45 65 85 105 125

°

T Free Air Temperature ( C)

A

°

Reference Current vs. Free Air T e m perature

200

V = V

KA REF

T = 25C

°

A

μ

100

I

KMIN

0

KA

I Cathode Current ( A)

-100

-2 -1 0 1 2 3
V Cathode Voltage (V)

KA

Cathode Current vs. Cathode Voltage

0.5

V = 36V

KA

V= 0

0.45

REF

μ

0.40

-100

-2 -1

-0.2

-0.3

-0.4

0

V Cathode Voltage

KA

12

Cathode Current vs. Cathode Voltage

V = 3V to 36V

KA

3

0.35

0.30

0.25

0.20

0.15

0.10

KOFF

I Off-State Cathode Current ( A)

-0.5

-0.6

REF KA

-0.7

dV /dV (mV/V)

-0.8

-0.9

0.05

0.00

-75

-50 -25 0 25 50
T Free Air Temperature ( C)

A

75

°

100 125

Off-State Cathode Current vs. Free Air Temperature

TL431 *SO-8 is a future package

Document number: DS35044 Rev. 6 - 2

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-1.0

-50 -25 0 25 50 75 100 125

Ratio of Delta Reference Voltage to Delta Cathode

T Free Air Temperature (C)

A

Voltage vs. Free Air Temperature

© Diodes Incorporated

April 2012

0

5

ADJUSTABLE PRECISION SHUNT REGULATOR

Typical Performance Characteristics (cont.)

40
380

√

360

I = 10mA

KA

V = V

KA RE F

T = 25°C

A

1

10

TL431/TL432

I = 10mA

KA

V = V

KA RE F

°

T = 25C

A

340
320

300
280
260
240

N

220

V = Equivalent Input Noise Voltage nV/ Hz

200

10 100 1K 10K 100K

Equivalent Input Noise Voltage vs. Frequency

f- Frequency (Hz)

5

0

-5

-10

Vn - Equivalent Input Noise Voltage - Vμ

-15
012345678910

Equivalent Input Noise Voltage Over A 10-S Period

Time (Seconds)

Figure 4. Test circuit for noise input voltage

TL431 *SO-8 is a future package

Document number: DS35044 Rev. 6 - 2

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ADJUSTABLE PRECISION SHUNT REGULATOR

Typical Performance Characteristics (cont.)

70

I = 10mA

KA

T = 25C

°

60

50

40

30

20

10

V

A Small-Signal Voltage Amplification (dB)

0

100

100.0

Ω

10.0

1.0

KA

0.1

Z Refer ence Impe danc e ( )

0.0
1K 10K

1K 10K 100K 1M

f Frequency (Hz)

Small-Signal Voltage Amplification vs. Frequency

100K

f Frequency (Hz)

Reference Impedance vs. Frequency

A

10M

I = 10mA

KA

T = 25C

°

A

1M 10M

TL431/TL432

Test circuit for voltage amplification

Test circuit for reference impedance

TL431 *SO-8 is a future package

Document number: DS35044 Rev. 6 - 2

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ADJUSTABLE PRECISION SHUNT REGULATOR

Typical Performance Characteristics (cont.)

6

T = 25C

°

Input

5

4

A

TL431/TL432

3

2

Input and Output Voltage (V)

1

Output

Test Circuit for Pulse Response

0

01 2

100

90
80
70

Stable

60

345678910

t Time ( s)

Stab le

μ

T = 25CA°

A

Stab le

Pulse Response

D

C

D

CB

50
40
30

KA

I - Cathode Current - mA

20
10

0

0.00001 0.0001

B

A V = V
B V = 5V
C V = 10V
D V = 15V

0.001 0.01 0.1 1

C -Load Capacitance - uF

L

Stability Boundary Conditions

KA REF

KA
KA
KA

10

Test Circuit for Curve A

Test circuit for curves B, C, D

Test Circuit for Curves B, C, D

The device is stable under all conditions with a load capacitance not exceeding 50pF. The device is stable under all
conditions with a load capacitance between 5nF and 20 nF. The device is stable und er all conditions with a load capacitance
exceeding 300nF. With a cathode current not exceed ing 5mA, the device is stable with any load capacitance.

TL431 *SO-8 is a future package

Document number: DS35044 Rev. 6 - 2

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Applications Information

TL431/TL432

ADJUSTABLE PRECISION SHUNT REGULATOR

TL431 *SO-8 is a future package

Document number: DS35044 Rev. 6 - 2

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Ordering Information

TL431/TL432

ADJUSTABLE PRECISION SHUNT REGULATOR

Device

TL431A(B)SA-7 SA SOT23 300 0/Tape & Reel -7 NA NA
TL431A(B)W5-7 W5 SOT25 3000/Tape & Reel -7 NA NA
TL431A(B)S-13* S SO-8* 2500/Tape & Reel -13 NA NA

TL432A(B)SA-7 SA SOT23 300 0/Tape & Reel -7 NA NA

* Suffix “B” denotes TL431B device.
Notes: 9. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at

http://www.diodes.com/datasheets/ap02001.pdf.

Package

Code

Packaging

(Note 9)

7” Tape and Reel Ammo Box

Quantity

Part Number

Suffix

Quantity

Part Number

Suffix

TL431 *SO-8 is a future package

Document number: DS35044 Rev. 6 - 2

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Marking Information

(1) SOT23

TL431/TL432

ADJUSTABLE PRECISION SHUNT REGULATOR

(Top View)

(2) SOT25

(3) SO-8*

Logo

Logo

Part Number

Part Number

XX

3

Y W X

: Identification code

XX

Y

:Year0~9

: Week : A~Z : 1~26 week;

W

a~z : 27~52 week; z represents
52 and 53 week

1

2

: A~Z : Green

X

Device Package Identification Code

TL431ASA SOT23 AA
TL431BSA SOT23 AB
TL432ASA SOT23 BA
TL432BSA SOT23 BB

Device Package Identification Code

TL431AW5 SOT25 AA
TL431BW5 SOT25 AB

(Top View)

(Top View)

8765

8765

TL431X

TL431X

YY WW X X

YY WW X X

234

234

1

1

X: tolerance A = 1%, B = 0.5%

X: tolerance A = 1%, B = 0.5%

YY

YY

: Year : 0 8, 09, 10~

: Year : 0 8, 09, 10~

: Week : 01~52; 52

: Week : 01~52; 52

WW

WW
represents 52 and 53 week

represents 52 and 53 week
XX: Inter nal Code

XX: Inter nal Code

TL431 *SO-8 is a future package

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A

⎯ ⎯

K

α

⎯

A

A

K

α

A

ADJUSTABLE PRECISION SHUNT REGULATOR

Package Outline Dimensions (All Dimensions in mm)

(1) Package type: SOT25

K

J

(2) Package Types: SOT23

K

F

J

A

B C

H

N

D

L

M

A

C

B

H

K1

D

G

L

M

TL431/TL432

SOT25

Dim Min Max Typ

0.35 0.50 0.38

B

1.50 1.70 1.60

C

2.70 3.00 2.80

D
H

2.90 3.10 3.00

J

0.013 0.10 0.05

1.00 1.30 1.10

L

0.35 0.55 0.40

M

0.10 0.20 0.15

N

0.70 0.80 0.75
0° 8°

ll Dimensions in mm

SOT23

Dim Min Max Typ

0.37 0.51 0.40

B

1.20 1.40 1.30

C

2.30 2.50 2.40

D

0.89 1.03 0.915

F

0.45 0.60 0.535

G

1.78 2.05 1.83

H

2.80 3.00 2.90

J

0.013 0.10 0.05

0.903 1.10 1.00

K1

- - 0.400

L

0.45 0.61 0.55

M

0.085 0.18 0.11
0° 8° -

ll Dimensions in mm

0.95

TL431 *SO-8 is a future package

Document number: DS35044 Rev. 6 - 2

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A

A

A

A

θ

ADJUSTABLE PRECISION SHUNT REGULATOR

Package Outline Dimensions (All Dimensions in mm)

(3) Package Types: SO-8*

E1

E

A1

Detail ‘A’

L

0.254

Gaug e Plan e
Seating Plane

7°~9

°

Detail ‘A’

A3

h

°

45

e

b

D

A2

A

TL431/TL432

SO-8*

Dim Min Max

- 1.75

1

0.10 0.20

2

1.30 1.50

3

0.15 0.25

b

0.3 0.5

D

4.85 4.95

E

5.90 6.10

E1

3.85 3.95

e
h
L

All Dimensions in mm

1.27 Typ

- 0.35

0.62 0.82
0° 8°

TL431 *SO-8 is a future package

Document number: DS35044 Rev. 6 - 2

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TL431/TL432

ADJUSTABLE PRECISION SHUNT REGULATOR

IMPORTANT NOTICE

DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS
DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION).

Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other
changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability
arising out of the application or use of this document or any product described herein; neither does Diodes Incorporated convey any
license under its patent or trademark rights, nor the rights of others. Any Customer or user of this document or products described
herein in such applications shall assume all risks of such use and will agree to hold Diodes Incorporated and all the companies
whose products are represented on Diodes Incorporated website, harmless against all damages.

Diodes Incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthorized
sales channel.
Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall
indemnify and hold Diodes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney fees
arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized application.

Products described herein may be covered by one or more United States, international or foreign patents pending. Product names
and markings noted herein may also be covered by one or more United States, international or foreign trademarks.

LIFE SUPPORT

Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without
the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:

A. Life support devices or systems are devices or systems which:

1. are intended to implant into the body, or

2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided
in the labeling can be reasonably expected to result in significant injury to the user.

B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected

to cause the failure of the life support device or to affect its safety or effectiveness.

Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or
systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements
concerning their products and any use of Diodes Incorporated products in such safety-critical, life support devices or systems,
notwithstanding any devices- or systems-related information or support that may be provided by Diodes Incorporated. Further,
Customers must fully indemnify Diodes Incorporated and its representatives against any damages arising out of the use of Diodes
Incorporated products in such safety-critical, life support devices or systems.

Copyright © 2012, Diodes Incorporated

www.diodes.com

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