Diodes AS431 User Manual

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Description

The AS431 is a three-terminal adjustable shunt regulator with
guaranteed thermal stability over a full operation range. It features
sharp turn-on characteristics, low temperature coefficient and low
output impedance, which make it ideal substitute for Zener diode in
applications such as switching power supply, charger and other
adjustable regulators.

The output voltage of AS431 can be set to any value between VREF
(2.5V) and the corresponding maximum cathode voltage (36V).

The AS431 precision reference is offered in two voltage tolerance:

0.5% and 1.0%.

This IC is available in 4 packages: TO-92 (bulk or ammo packing),
SOT-23, SOT-23-5 and SOT-89.

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ADJUSTABLE PRECISION SHUNT REGULATORS

Features

 Programmable Precise Output Voltage from 2.5V to 36V
 High Stability under Capacitive Load
 Low Temperature Deviation: 4.5mV Typical
 Low Equivalent Full-range Temperature Coefficient with

20PPM/°C Typical

 Sink Current Capacity from 1mA to 100mA
 Low Output Noise
 Wide Operating Range of -40 to +125°C
 Lead-Free Packages: SOT-23, SOT-23-5, TO-92, SOT-89

 Totally Lead-Free; RoHS Compliant (Notes 1 & 2)

 Lead-Free Packages, Available in “Green” Molding Compound:

SOT-23, SOT-23-5, TO-92, SOT-89

 Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
 Halogen and Antimony Free. “Green” Device (Note 3)

S431

Applications

 Charger
 Voltage Adapter
 Switching Power Supply
 Graphic Card
 Precision Voltage Reference

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.

Pin Assignments

N Package R Package R Package

(SOT-23) (SOT-89 Option 1) (SOT-89 Option 2)

123

REF CATHODEANODE

1

REF CATHODEANODE

2

3

K Package Z Package Z Package

(SOT-23-5) (TO-92 (Bulk Packing)) (TO-92 (Ammo Packing

3

CATHODE

2

ANODE

1

REF

Note: 4. * Pin 2 is attached to substrate and must be connected to ANODE or open.

AS431

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S431

Typical Applications Circuit

Shunt Regulator

AS431

Document number: DS36599 Rev. 3 - 2

High Current Shunt Regulator

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S431

Typical Applications Circuit

(Cont.)

Current Source or Current Limit

AS431

Document number: DS36599 Rev. 3 - 2

Precision 5V 1A Regulator

PWM Converter with Reference

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S431

Functional Block Diagram

Absolute Maximum Ratings

(Note 5)

Symbol Parameter

V

KA

I

KA

I

REF

PD

TJ

T

STG

ESD ESD (Human Body Model) 2000 V

Note 5: Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and

functional operation of the device at these or any other conditions beyond those indicated under “Recommended Operating Conditions” is not implied.
Exposure to “Absolute Maximum Ratings” for extended periods may affect device reliability.

Cathode Voltage 40 V

Cathode Current Range (Continuous) -100 to 150 mA

Reference Input Current Range 10 mA

Power Dissipation

Junction Temperature +150 °C

Storage Temperature Range -65 to +150 °C

Z, R Package 770

N, K Package 370

Rating

Recommended Operating Conditions

Unit

mW

Symbol Parameter

V

I

TA

KA

KA

Cathode Voltage

Cathode Current 1.0 100

Operating Ambient Temperature Range -40 +125

Min Max

V

REF

36

Unit

V

mA

°C

AS431

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S431

Electrical Characteristics

(Operating Conditions: TA = +25°C, unless otherwise specified.)

Symbol Parameter

V

REF

∆V

REF

∆V

REF

∆VKA

I

REF

∆I

REF

I

KA

(Min)

I

KA

(Off)

Z

KA

θ

JC

Reference Voltage

Deviation of Reference Voltage
Over Full Temperature Range

Ratio of Change in Reference
Voltage to the Change in Cathode
Voltage

Reference Current 5

Deviation of Reference Current
Over Full Temperature Range

Minimum Cathode Current for
Regulation

Off-state Cathode Current 6

Dynamic Impedance 4

Thermal Resistance –

0.5%

1.0% 2.475 2.500 2.525

Test

Circuit

4

4

5

5

4

Conditions Min Typ Max Unit

= V

, I

REF

= 10mA

KA

V

KA

0 to +70°C – 4.5 8

V

= V

REF

= 10mA

,

-40 to +85°C – 4.5 10

KA

I

KA

-40 to +125°C – 4.5 16

= 10V to V

∆V

REF

∆V

= 0

KA

KA

= 36V to 10V

I

= 10mA

KA

I

= 10mA, R1 = 10KΩ, R2 = ∞

KA

= 10mA, R1 = 10KΩ, R2 = ∞,

I

KA

T

= -40 to +125°C

A

V

= V

KA

V

KA

V

KA

REF

= 36V, V

= V

, IKA = 1 to 100mA,

REF

f ≤ 1.0KHz

SOT-23

SOT-23-5

TO-92

SOT-89

REF

2.487 2.500 2.512

– -1.0 -2.7

– -0.5 -2.0

–

–

–

–

–

–

–

–

–

0.7 4

0.4 1.2

0.4 1.0

0.05 1.0

0.15 0.5

135.9

135.9

81.9

29.8

V

mV

mV/V

µA

µA

mA

µA

Ω

–

–

°C/W

–

–

AS431

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Electrical Characteristics

(Cont.)

Test Circuit 4 for V

= V

KA

REF

AS431

Document number: DS36599 Rev. 3 - 2

Test Circuit 5 for V

KA

> V

REF

Test Circuit 6 for I

OFF

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Performance Characteristics

Reference Voltage vs. Ambient Temperature Reference Current vs. Ambient Temperature

2.510

VKA = V

REF

IKA = 10mA

2.505

2.500

1.5

1.0

R1=10K,R2=Infinite
I

=10mA

KA

2.495

Reference Voltage (V)

2.490

0.5

Reference Current (A)

2.485

-60 -40 -20 0 20 40 60 80 100 120 140

Ambient Temperature (oC)

0.0

-60 -40 -20 0 20 40 60 80 100 120 140

Ambient Temperature (0C)

Cathode Current vs. Cathode Voltage Cathode Current vs. Cathode Voltage

150

100

VKA=V

TA=250C

REF

50

Cathode Current (mA)

-50

0

-100

-2 -1 0 1 2 3

Cathode Voltage (V)

800

VKA=V

REF

TA=250C

600

400

200

0

Cathode Current (A)

-200

-1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5

Cathode Voltage (V)

Off-State Cathode Current Ratio of Delta Reference Voltage to the

vs. Ambient Temperature Ratio of Delta Cathode Voltage

2.0

1.8

Off-State Cathode Current (A)

VKA=36V
V

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

=0

REF

-40-200 20406080100120

Ambient Temperature (oC)

-0.9

-1.0

-1.1

(mV/V)

KA

/ V

-1.2

REF

V

-1.3

-1.4

-40 -20 0 20 40 60 80 100 120

Ambient Temperature (oC)

VKA=3.5V to 36V

AS431

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S431

Performance Characteristics

(Cont.)

Small Signal Voltage Gain vs. Frequency

70

60

50

40

30

20

Voltage Gain (dB)

10

0

-10
1k 10k 100k 1M

Small Signal Frequency (Hz)

TA=250C

=10mA

I

KA

Reference Impedance vs. Frequency

IKA=10mA

=25oC

T

10

A

1

Reference Impedance ()

0.1
1K 10K 100K 1,000K

Frequency (Hz)

Stability Boundary Conditions vs. Load Capacitance

100

90

80

70

Stable

60

50

40

30

Cathode Current (mA)

20

10

0

Load Capacitance (F)

Stable

TA=25oC

VKA=V

VKA= 5V:No oscillation

=10V:No oscillation

V

KA

=15V:No oscillation

V

KA

0.10.010.001

REF

1

10

AS431

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Performance Characteristics

(Cont.)

Pulse Response of Input and Output Voltage

5

4

3

2

Input and Output Voltage (V)

1

0

0246

Input

Output

Time (S)

AS431

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Ordering Information

Package

Temperature

AS431

Circuit Type

Voltage Tolerance
A: 0.5%
B: 1.0%

Package
N: SOT-23
K: SOT-23-5
R: SOT-89
Z: TO-92

Voltage

Range

Tolerance

Lead Free Green Lead Free Green

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-

E1: Lead Free
G1: Green

TR: Tape & Reel or Ammo
Blank: Bulk

Part Number Marking ID

S431

Packing

Type

Pb

Lead-Free

SOT-23

-40 to +125°C

Pb

Lead-Free

Pb

Lead-Free

SOT-23-5

TO-92

-40 to +125°C

-40 to +125°C

Pb

Lead-Free

BCD Semiconductor's Pb-free products, as designated with "E1" suffix in the part number, are RoHS compliant. Products with "G1" suffix are available in green
packages.

SOT-89

-40 to +125°C

0.5%

1.0%

0.5%

1.0%

0.5%

0.5%

1.0%

1.0%

0.5%

1.0%

AS431ANTR-E1 AS431ANTR-G1 EB5 GB5

AS431BNTR-E1 AS431BNTR-G1 EB6 GB6

AS431AKTR-E1 AS431AKTR-G1 E6H G6H

AS431BKTR-E1 AS431BKTR-G1 E6I G6I

AS431AZ-E1 AS431AZ-G1 AS431AZ-E1 AS431AZ-G1

AS431AZTR-E1 AS431AZTR-G1 AS431AZ-E1 AS431AZ-G1

AS431BZ-E1 AS431BZ-G1 AS431BZ-E1 AS431BZ-G1

AS431BZTR-E1 AS431BZTR-G1 AS431BZ-E1 AS431BZ-G1

AS431ARTR-E1 AS431ARTR-G1 E43G G43G

AS431BRTR-E1 AS431BRTR-G1 E43H G43H

Tape &

Reel

Tape &

Reel

Tape &

Reel

Tape &

Reel

Bulk

Ammo

Bulk

Ammo

Tape &

Reel

Tape &

Reel

AS431

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Package Outline Dimensions

1.000(0.039)



1.40 0(0.0 55)

(All dimensions in mm(inch).)

TO-92 (Bulk Packing)

3.4 30(0. 135)
MIN

3.300(0 .130)

3.700(0 .146)

4.40 0(0. 1 73)

4.80 0(0. 1 89)

0.3 20(0. 013)

0.5 10(0. 020)

0. 000(0. 0 00)

0. 380(0. 0 15)

F 1. 600(0. 0 63)

MAX

AS431

Document number: DS36599 Rev. 3 - 2

4. 3 00 ( 0 .16 9 )

4. 7 00 ( 0 .18 5 )

1.27 0(0. 05 0)
TY P

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0.3 60( 0. 014)

0.7 60( 0. 030)

12 . 50 0( 0 .4 9 2)

15 . 50 0( 0 .6 1 0)

2.420(0. 0 95)

2.660(0. 1 05)

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S431

Package Outline Dimensions

1.100(0.043

1.400(0.055

)

)

3.300(0.130)

3.800(0.150)

3.430(0.135)
MIN

Φ1.600(0.063)

(Cont. All dimensions in mm(inch).)

TO-92 (Ammo Packing)

4.300(0. 169)

0.320(0.013

0.510(0.020

0.000(0.000

0.380(0.015)

MAX

)
)

)

2.500( 0. 492)14.500( 0. 571)
1

4.400(0.173

4.800(0.189

4.700(0. 185)

)
)

1.270(0.050)
Typ

2.500(0. 098

4.000(0.157

)
)

13.000(0.512
(

15.

0.

000

591

)

)

AS431

Document number: DS36599 Rev. 3 - 2

0. (0.015)

380

0.550(0. 022)

Ty

)

p

2.540(0. 100

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Package Outline Dimensions

3.0°

0.500(0.020)

0.700(0.028)

2.0°

1.050(0.041)REF

2.800(0.110)

3.000(0.118)

(Cont. All dimensions in mm(inch).)

SOT-23

R0.100(0.004)

4×

0.900(0.035)

1.100(0.043)

0.010(0.0004)

0.100(0.004)

0.0°~10.0°

0.2 0 0(0. 0 0 8)MIN

0.550(0.022)REF

0.100(0.004) GAUGE PLANE

7.0°

R0.100(0.004)

7.0°

0.080(0.003)

0.180(0.007)

2.300(0.091)

2.500(0.098)

0.890(0.035)

1.030(0.041)

AS431

Document number: DS36599 Rev. 3 - 2

1.900(0.075)REF

1.200(0.047)

1.400(0.055)

0.300(0.012)

0.510(0.020)

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Package Outline Dimensions

)

)

8

4

1

0

1

1

.

.

0

0

(

(

0

0

0

5

0

6

.

.
2

3

(Cont. All dimensions in mm(inch).)

SOT-23-5

2.820(0.111)

3.100(0.122)

)

)

9

7

5

6

0

0

.

.

0

0

(

(

0

0

0

0

5

7

.

.

1

1

0.200(0.008)

0

0

.

.

0

(

7

0

F

E

R

0.100(0.004)

0.200(0.008)

)

)

4

2

2

1

0

0

.

.

0

0

(

(
0

0

0

0

3

6

.

.

0

0

0

2

8

)

0.950(0.037)

P

T

Y

)
7
5
0

.

X

0

A

(
0

M

5
4

.
1

AS431

Document number: DS36599 Rev. 3 - 2

0.300(0.012)

0.500(0.020)

0°

8°

1.800(0.071)

2.000(0.079)

.

0

.

0

0

0

0

(

9

.

0

0

1

.

(

3

0

0

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0

0

)

0

.

0

0

0

(

0

0

6

)

0

.

0

5

0

(

1

3

5

)

0

.

.

)

0

5

1

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Package Outline Dimensions

3. 950( 0.1 56)

4. 250( 0.1 67)

0.900(0.035)

1.200(0.047)

0.320(0.013)

0.540(0.021)

3.000(0.118)

(Cont. All dimensions in mm(inch).)

SOT-89

4.400(0.173)

4.60 0(0.18 1)

Option 1

2.300(0.091)

2.600(0.102)

0.320(0.013)

0.540(0.021)

0.48 0(0.01 9)

0.620(0.024)

TYP

3

1.400(0.055)

1.600(0.063)

2.06 0(0.08 1)RE F

3

0.350(0.014)

0.450(0.018)

10

R0.150(0.006)

2.210(0.087)REF

Option 1 Option 2

1.550(0.061)REF

1.500(0.059)

1.800(0.071)

1.030(0.041)REF

45

10

0.320(0.013)REF

1.620(0.064)REF

AS431

Document number: DS36599 Rev. 3 - 2

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R 0.200(0.008)

1.620(0.064)

1.83 0(0.07 2)

2.630(0.104)

2.930(0.115)

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Suggested Pad Layout

SOT-23

Grid placement courtyard

Y

Z

G

Y

XE

Dimensions

Value 2.900/0.114 1.100/0.043 0.800/0.031 0.900/0.035 0.950/0.037

Z

(mm)/(inch)

G

(mm)/(inch)

X

(mm)/(inch)

Y

(mm)/(inch)

E

(mm)/(inch)

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Suggested Pad Layout

(Cont.)

SOT-23-5

E2

G

Z

E1

Y

Dimensions

Value 3.600/0.142 1.600/0.063 0.700/0.028 1.000/0.039 0.950/0.037 1.900/0.075

Z

(mm)/(inch) G (mm)/(inch) X (mm)/(inch) Y (mm)/(inch)

X

E1

(mm)/(inch)

E2

(mm)/(inch)

AS431

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Suggested Pad Layout



(Cont.)

SOT-89

X1

Z

X2

Y

Dimensions

Value 4.600/0.181 0.550/0.022 1.850/0.073 0.800/0.031 1.300/0.051 1.475/0.058 1.500/0.059

Z

(mm)/(inch) X (mm)/(inch)

X1

(mm)/(inch)

(mm)/(inch) Y (mm)/(inch)

EX

X2

Y1

Y1

(mm)/(inch) E (mm)/(inch)

AS431

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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.

This document is written in English but may be translated into multiple languages for reference. Only the English version of this document is the
final and determinative format released by Diodes Incorporated.

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
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representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems.

Copyright © 2013, Diodes Incorporated

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IMPORTANT NOTICE

LIFE SUPPORT

AS431

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