
AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
Description
The AZ431-A 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 AZ431-A can be set to any value between V
REF
(2.5V) and the corresponding maximum cathode voltage (36V).
The AZ431-A precision reference is offered in two voltage tolerance:
0.4% and 0.8%.
This IC is available in 4 packages: TO92 (bulk or ammo packing),
SOT23, SOT25 and SOT89.
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/oC Typical
Sink Current Capacity from 1mA to 100mA
Low Output Noise
Wide Operating Range of -40 to +125oC
Lead-Free Packages: TO92, SOT23, SOT25, SOT89
Totally Lead-Free; RoHS Compliant (Notes 1 & 2)
Lead-Free Packages, Available in “Green” Molding Compound:
TO92, SOT23, SOT25, SOT89
Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
Applications
Charger
Voltage Adapter
Switching Power Supply
Graphic Card
Precision Voltage Reference
ADJUSTABLE PRECISION SHUNT REGULATORS
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
(Top View) (Top View) (Top View)
SOT23 SOT89 (Option 1) SOT89 (Option 2)

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
1
2
3 4
5
REF
ANODENC
*
CATHODE
(Note 4)
Pin Assignments (Cont.)
Note 4: * Pin 2 is attached to substrate and must be connected to ANODE or open.
(Top View) (Top View) (Top View)
SOT25 TO92 (Bulk Packing) TO92 (Ammo Packing)
Typical Applications Circuit
Shunt Regulator
High Current Shunt Regulator

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
Typical Applications Circuit (Cont.)
Current Source or Current Limit
Precision 5V 1A Regulator
PWM Converter with Reference

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
Cathode Current Range (Continuous)
Reference Input Current Range
Thermal Resistance
(Junction to Ambient)
Storage Temperature Range
Operating Ambient Temperature Range
Functional Block Diagram
Absolute Maximum Ratings (Note 5)
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.
Recommended Operating Conditions

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
V
KA
= V
REF
, I
KA
= 10mA
Deviation of Reference Voltage
Over Full Temperature Range
Ratio of Change in Reference
Voltage to the Change in
Cathode Voltage
I
KA
= 10mA, R1 = 10KΩ, R2 =
∞
Deviation of Reference Current
Over Full Temperature Range
I
KA
= 10mA, R1 = 10KΩ
R2 = ∞, TA = -40 to +125oC
Minimum Cathode Current for
Regulation
Off-state Cathode Current
V
KA
= V
REF
, I
KA
= 1 to 100mA,
f ≤ 1.0KHz
Electrical Characteristics (@T
= +25°C, unless otherwise specified.)
A

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
Electrical Characteristics (Cont.)
Test Circuit 4 for V
= V
KA
REF
Test Circuit 5 for V
KA
> V
REF
Test Circuit 6 for I
OFF

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
-60 -40 -20 0 20 40 60 80 100 120 140
2.485
2.490
2.495
2.500
2.505
2.510
Reference Voltage (V)
Ambient Temperature (oC)
VKA = V
REF
IKA = 10mA
-60 -40 -20 0 20 40 60 80 100 120 140
0.0
0.5
1.0
1.5
R1=10K,R2=Infinite
IKA=10mA
Reference Current (
A)
Ambient Temperature (0C)
-2 -1 0 1 2 3
-100
-50
0
50
100
150
Cathode Current (mA)
Cathode Voltage (V)
VKA=V
REF
TA=250C
-1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5
-200
0
200
400
600
800
Cathode Current (
A)
Cathode Voltage (V)
VKA=V
REF
TA=250C
-40 -20 0 20 40 60 80 100 120
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Off-State Cathode Current (
A)
Ambient Temperature (oC)
VKA=36V
V
REF
=0
-40 -20 0 20 40 60 80 100 120
-1.4
-1.3
-1.2
-1.1
-1.0
-0.9
VKA=3.5V to 36V
V
REF
/ V
KA
(mV/V)
Ambient Temperature (oC)
Performance Characteristics
Reference Voltage vs. Ambient Temperature Reference Current vs. Ambient Temperature
Cathode Current vs. Cathode Voltage Cathode Current vs. Cathode Voltage
Off-State Cathode Current vs. Ambient Temperature Ratio of Delta Reference Voltage to the
Ratio of Delta Cathode Voltage

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
1k 10k 100k 1M
-10
0
10
20
30
40
50
60
70
Voltage Gain (dB)
Small Signal Frequency (Hz)
TA=250C
IKA=10mA
1K 10K 100K 1,000K
0.1
1
10
Reference Impedance (
)
Frequency (Hz)
IKA=10mA
TA=25oC
1E-3 0.01 0.1 1 10 100
0
10
20
30
40
50
60
70
80
90
100
VKA=V
REF
VKA= 5V
VKA=10V
VKA=15V: No Oscillation
Stable
Stable
Cathode Current (mA)
Load Capacitance (F)
Performance Characteristics (Cont.)
Small Signal Voltage Gain vs. Frequency
Reference Impedance vs. Frequency
Stability Boundary Conditions vs. Load Capacitance

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
0 2 4 6
0
1
2
3
4
5
Input
Input and Output Voltage (V)
Time (S)
Output
Performance Characteristics (Cont.)
Pulse Response of Input and Output Voltage

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
AZ431 X X- X XX XX
Packing
Package
TR : Tape & Reel
N : SOT23
K : SOT25
Product Name
E1/G1
Blank : Bulk
E1 : RoHS Compliant
G1 : Green
R : SOT89
Z : TO92
Voltage Tolerance
A: 40V
Cathode Voltage
A : 0.4%
B : 0.8%
or Ammo
Ordering Information

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
: Logo
XXX: Marking ID
(See Ordering Information)
First and Second Lines: Logo and Marking ID
(See Ordering Information)
Third Line: Date Code
Y: Year
WW: Work Week of Molding
A: Assembly House Code
XX: 7th and 8th Digits of Batch Number
Marking Information
(1) TO92
(2) SOT23
(Top View)
(Top View)

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
: Logo
XXXX: Marking ID
(See Ordering Information)
: Logo
XXX: Marking ID
(See Ordering Information)
Marking Information (Cont.)
(3) SOT25
(4) SOT89
(Top View)
(Top View)

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
2.420(0.095)
2.660(0.105)
0.360(0.014)
0.760(0.030)
Φ
1.600(0.063)
MAX
12.500(0.492)
15.500(0.610)
1.270(0.050)
TYP
3.300(0.130)
3.700(0.146)
4.300(0.169)
4.700(0.185)
1.000(0.039)
1.400(0.055)
4.400(0.173)
4.800(0.189)
3.430(0.135)
MIN
0.320(0.013)
0.510(0.020)
0.000(0.000)
0.380(0.015)
Package Outline Dimensions (All dimensions in mm.)
(1) Package Type: TO92 (Bulk Packing)

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
4.300(0.169)
4.700(0.185)
1
2.500(0.492)14.500(0.571)
2.540(0.100
)
Ty
p
1.270(0.050
)
Typ
0.
(0.015)
0.
550
(0.022
)
4.400(0.173
)
4.
800
(
0.
189
)
3.430(0.135
)
MIN
0.320(0.013
)
0
.510(0.020
)
0.000(0.000
)
0.380(0.015
)
MAX
1.100(0.043
1.400(0.055
)
3.300(0.130)
3.800(0.150)
Φ
1.600(0.063)
)
380
2.500(0.098
)
4.
000
(
0.
157
)
13.000(0.512
)
15.
000
(
0.
591
)
Package Outline Dimensions (Cont. All dimensions in mm.)
(2) Package Type: TO92 (Ammo Packing)

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
2.300(0.091)
2.500(0.098)
1.200(0.047)
1.400(0.055)
0.890(0.035)
1.030(0.041)
0.300(0.012)
0.510(0.020)
1.900(0.075)REF
2.800(0.110)
3.000(0.118)
2.0°
3.0°
0.500(0.020)
0.700(0.028)
1.050(0.041)REF
0.010(0.0004)
0.100(0.004)
0.900(0.035)
1.100(0.043)
4×
R0.100(0.004)
7.0°
7.0°
0.550(0.022)REF
0.200(0.008)MIN
0.100(0.004) GAUGE PLANE
0.080(0.003)
0.180(0.007)
R0.100(0.004)
0.0°~10.0°
Package Outline Dimensions (Cont. All dimensions in mm.)
(3) Package Type: SOT23

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
2.820(0.111)
2.650(0.104)
1
.
500
(
0
.
059
)
0
.
000
(
0
.
000
)
0.300(0.012)
0.950(0.037)
0
.
900
(
0
.
035
)
0.100(0.004)
0.200(0.008)
0
.
300
(
0
.
012
)
8°
0°
3.100(0.122)
1
.
700
(
0
.
067
)
3
.
000
(
0
.
118
)
0.500(0.020)
0
.
150
(
0
.
006
)
1
.300(
0.051
)
0.200(0.008)
0
.
600
(
0
.
024
)
1.800(0.071)
2.000(0.079)
0
.
700
(
0
.
028
)
REF
TYP
1
.
450
(
0
.
057
)
MAX
Package Outline Dimensions (Cont. All dimensions in mm.)
(4) Package Type: SOT25

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
45
1.550(0.061)REF
4.400(0.173)
4.600(0.181)
0.900(0.035)
1.200(0.047)
3.950(0.156)
4.250(0.167)
3.000(0.118)
TYP
0.480(0.019)
2.300(0.091)
2.600(0.102)
0.320(0.013)
0.540(0.021)
3
10
2.060(0.081)REF
1.400(0.055)
1.600(0.063)
0.350(0.014)
0.450(0.018)
R0.150(0.006)
3
10
1.500(0.059)
0.320(0.013)REF
1.620(0.064)REF
2.210(0.087)REF
0.320(0.013)
0.540(0.021)
1.800(0.071)
Option 1 Option 2
0.620(0.024)
1.030(0.041)REF
R 0.200(0.008)
1.620(0.064)
1.830(0.072)
2.630(0.104)
2.930(0.115)
Option 1
Package Outline Dimensions (Cont. All dimensions in mm.)
(5) Package Type: SOT89

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
Y
G
Z
Y
X E
Grid placement courtyard
Suggested Pad Layout
(1) Package Type: SOT23

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
Suggested Pad Layout (Cont.)
(2) Package Type: SOT25

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
Suggested Pad Layout (Cont.)
(3) Package Type: SOT89

AZ431-A
Document number: DS36721 Rev. 5 - 2
September 2015
© Diodes Incorporated
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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).
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final and determinative format released by Diodes Incorporated.
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written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:
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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.
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failure of the life support device or to affect its safety or effectiveness.
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www.diodes.com
IMPORTANT NOTICE
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