Page 1
AS431I
Document number: DS36816 Rev. 2 - 2
1 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
Diodes Incorporated
Description
The AS431I 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 AS431I can be set to any value between V
REF
(2.5V) and the corresponding maximum cathode voltage (36V).
The AS431I is offered in two grade initial voltage tolerance at +25oC,
0.5%, and 1%.
This IC is available in 3 packages: TO-92 (bulk or ammo packing),
SOT-23 and SOT-89.
Features
Programmable Precise Output Voltage from 2.5V to 36V
High Stability Under Capacitive Load
Low Minimum Cathode Current for Regulation: 10µA (Typ.), 50µA
(Max.)
Low Temperature Deviation: 4.5mV Typical
Sink Current Capacity from 50µA to 100mA
Low Output Noise
Wide Operating Range: -40 to +125oC
Applications
Charger
Voltage Adapter
Switching Power Supply
Graphic Card
Precision Voltage Reference
1 2 3
REF ANODE CATHODE
CATHODE
ANODE
REF
3
2
1
1 2
3
REF ANODE CATHODE
LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR
Pin Assignments
(Top View) (Top View) (Top View)
(SOT-23/ N Package) (SOT-89 (Option 1/ R Package) (SOT-89 (Option 2/ R Package)
Page 2
AS431I
Document number: DS36816 Rev. 2 - 2
2 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
Diodes Incorporated
1
2
3
CATHODE
ANODE
REF
CATHODE
ANODE
REF
1
2
3
V
OUT
=(1+R1/R2)*V
REF
V
OUT
=(1+R2/R3)*V
REF
Pin Assignments (Cont.)
(Top View) (Top View)
(TO-92 (Bulk Packing)/ Z Package) (TO-92 (Ammo Packing)/ Z Package)
Typical Applications Circuit
Shunt Regulator
High Current Shunt Regulator
Page 3
AS431I
Document number: DS36816 Rev. 2 - 2
3 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
Diodes Incorporated
I
OUT=VREF
/R2+ I
KA
Typical Applications Circuit (Cont.)
Current Source or Current Limit
Precision 5V 1A Regulator
PWM Converter with Reference
Page 4
AS431I
Document number: DS36816 Rev. 2 - 2
4 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
Diodes Incorporated
REF
V
REF
CATHODE
ANODE
+
-
Symbol
Parameter
Rating
Unit
VKA
Cathode Voltage
40
V
I
KA
Cathode Current Range (Continuous)
-100 to 150
mA
I
REF
Reference Input Current Range
10
mA
P
D
Power Dissipation
TO-92
770
mW
SOT-89
770
SOT-23
370
TJ
Junction Temperature
+150
ºC
T
STG
Storage Temperature Range
-65 to +150
ºC
ESD
ESD (Human Body Model)
2000
V
Symbol
Parameter
Min
Max
Unit
V
KA
Cathode Voltage
V
REF
36 V I
KA
Cathode Current
0.05
100
mA
TA
Operating Ambient Temperature Range
-40
+125
ºC
Functional Block Diagram
Absolute Maximum Ratings (Note 1)
Note 1: Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stres s 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
Page 5
AS431I
Document number: DS36816 Rev. 2 - 2
5 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
Diodes Incorporated
Symbol
Parameter
Test
Circuit
Conditions
Min
Typ
Max
Unit
V
REF
Reference Voltage
0.5%
4
V
KA
= V
REF
, I
KA
= 10mA
2.487
2.500
2.512
V
1.0%
2.475
2.500
2.525
∆V
REF
Deviation of Reference Voltage
Over Full Temperature Range
4
V
KA
= V
REF
,
I
KA
= 10mA
0 to +70°C
–
4.5
8
mV
-40 to +85°C
–
4.5
10
-40 to +125°C
–
4.5
16
∆V
REF
∆VKA
Ratio of Change in Reference
Voltage to the Change in Cathode
Voltage
5
I
KA
= 10mA
∆V
KA
= 10V to V
REF
–
-1.0
-2.7
mV/V
∆V
KA
= 36V to 10V
–
-0.5
-2.0
I
REF
Reference Current
5
I
KA
= 10mA, R1 = 10KΩ, R2 = ∞
–
0.035
0.5
µA
∆I
REF
Deviation of Reference Current
Over Full Temperature Range
5
I
KA
= 10mA, R1 = 10KΩ, R2 = ∞,
TA = -40 to +125°C
–
0.03
0.3
µA
I
KA
(Min)
Minimum Cathode Current for
Regulation
4
V
KA
= V
REF
–
10
50
µA
I
KA
(Off)
Off-state Cathode Current
6
V
KA
= 36V, V
REF
= 0
–
0.05
1.0
µA
Z
KA
Dynamic Impedance
4
V
KA
= V
REF
, IKA = 1 to 100mA,
f ≤ 1.0KHz
–
0.15
0.5
Ω
θ
JC
Thermal Resistance
–
TO-92 – 68
–
°C/W
SOT-89
–
29
–
SOT-23
–
113
–
Electrical Characteristics (Operating Conditions: T
= +25ºC, unless otherwise specified.)
A
Page 6
AS431I
Document number: DS36816 Rev. 2 - 2
6 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
Diodes Incorporated
V
IN
V
KA
R1
I
KA
V
REF
V
IN
V
KA
I
KA
R1
R2
V
REF
VKA=V
REF
(1+R1/R2)+ I
REF
*R1
I
REF
R3
I
OFF
V
IN
V
KA
R
1
Electrical Characteristics (Cont.)
Test Circuit 4 for V
= V
KA
REF
Test Circuit 5 for V
> V
KA
REF
Test Circuit 6 for I
OFF
Page 7
AS431I
Document number: DS36816 Rev. 2 - 2
7 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
Diodes Incorporated
-1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0
-50
-40
-30
-20
-10
0
10
20
30
40
50
Cathode Current (
A)
Cathode Voltage (V)
VKA=V
REF
TA=25oC
-60 -40 -20 0 20 40 60 80 100 120 140
2.48
2.49
2.50
2.51
2.52
Reference Voltage (V)
Temperature (0C)
VKA=V
REF
IKA=10mA
-1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0
-120
-100
-80
-60
-40
-20
0
20
40
60
80
100
120
Cathode Current (mA)
Cathode Voltage (V)
VKA=V
REF
TA=25oC
-60 -40 -20 0 20 40 60 80 100 120 140
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
Off-state Cathode Current (
A)
Temperature (0C)
VKA=36V
V
REF
=0
-60 -40 -20 0 20 40 60 80 100 120 140
-0.6
-0.4
-0.2
0.0
0.2
0.4
V
REF
/V
KA
(mV/V)
Temperature (0C)
VKA=3.5V to 36V
-40 -20 0 20 40 60 80 100 120
0.020
0.025
0.030
0.035
0.040
0.045
0.050
0.055
Reference Current (
A)
Temperature (oC)
R1=10K, R2=infinite
I
KA
=10mA
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
Page 8
AS431I
Document number: DS36816 Rev. 2 - 2
8 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
Diodes Incorporated
10F
8.2K
15K
I
KA
Output
242
GND
1k 10k 100k
-30
-20
-10
0
10
20
30
40
50
60
Small Signal Voltage Gain (dB)
Frequence (Hz)
IKA=10mA
TA=25oC
300k
0
10
20
30
40
50
60
70
80
90
100
Stable
10
1
0.1
0.01
Cathode Current (mA)
Load Capacitor (F)
VKA=V
REF
VKA=5V
VKA=10V
VKA>10V, No Oscillation
0.001
Stable
I
KA
R1 (10K)
R2
150
V
IN
V
out
Pulse
Generator
f=100KHz
220
50
Output
GND
Performance Characteristics (Cont.)
Small Signal Voltage Gain vs. Frequency
Stability Boundary Conditions vs. Load Capacitance
Pulse Response of Input and Output Voltage
Page 9
AS431I
Document number: DS36816 Rev. 2 - 2
9 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
Diodes Incorporated
AS431I X X XX – XX
Packing
Package
TR : Tape & Reel
A : 0.5%
B : 1.0%
Product Name
Blank : Bulk
G1 : Green
Voltage Tolerance
Z : TO-92
N : SOT-23
R : SOT-89
or Ammo
RoHS/Green
Package
Temperature
Range
Voltage
Tolerance
Part Number
Marking ID
Packing Type
SOT-23
-40 to +125°C
0.5%
AS431IANTR-G1
GB8
Tape & Reel
1.0%
AS431IBNTR-G1
GC9
Tape & Reel
TO-92
-40 to +125°C
0.5%
AS431IAZ-G1
AS431IAZ-G1
Bulk
0.5%
AS431IAZTR-G1
AS431IAZ-G1
Ammo
1.0%
AS431IBZ-G1
AS431IBZ-G1
Bulk
1.0%
AS431IBZTR-G1
AS431IBZ-G1
Ammo
SOT-89
-40 to +125°C
0.5%
AS431IARTR-G1
G43J
Tape & Reel
1.0%
AS431IBRTR-G1
G43K
Tape & Reel
Ordering Information
Diodes IC’s Pb-free products with "G1" suffix in the part number, are RoHS compliant and green.
Page 10
AS431I
Document number: DS36816 Rev. 2 - 2
10 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
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(inch).)
(1) Package Type: TO-92 (Bulk Packing)
Page 11
AS431I
Document number: DS36816 Rev. 2 - 2
11 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
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(inch).)
(2) Package Type: TO-92 (Ammo Packing)
Page 12
AS431I
Document number: DS36816 Rev. 2 - 2
12 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
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(inch).)
(3) Package Type: SOT-23
Page 13
AS431I
Document number: DS36816 Rev. 2 - 2
13 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
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(inch).)
(4) Package Type: SOT-89
Page 14
AS431I
Document number: DS36816 Rev. 2 - 2
14 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
Diodes Incorporated
Y
G
Z
Y
X E
Grid placement courtyard
Dimensions
Z
(mm)/(inch)
G
(mm)/(inch)
X
(mm)/(inch)
Y
(mm)/(inch)
E
(mm)/(inch)
Value
2.900/0.114
1.100/0.043
0.800/0.031
0.900/0.035
0.950/0.037
Suggested Pad Layout
(1) Package Type: SOT-23
Page 15
AS431I
Document number: DS36816 Rev. 2 - 2
15 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
Diodes Incorporated
X1
X2
Y1
E
X
Y
Z
Dimensions
Z
(mm)/(inch)
X
(mm)/(inch)
X1
(mm)/(inch)
X2
(mm)/(inch)
Y
(mm)/(inch)
Y1
(mm)/(inch)
E
(mm)/(inch)
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
Suggested Pad Layout (Cont.)
(2) Package Type: SOT-89
Page 16
AS431I
Document number: DS36816 Rev. 2 - 2
16 of 16
www.diodes.com
January 2014
© Diodes Incorporated
AS431I
A Product Line of
Diodes Incorporated
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
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
IMPORTANT NOTICE
LIFE SUPPORT
Loading...