Data Sheet
ADJUSTABLE PRECISION SHUNT REGULATORS
General Description
The AS431 is a three-terminal adjustable shunt regula-
tor with guaranteed thermal stability over a full opera-
tion range. It features sharp turn-on characteristics, low
temperature coefficient and low output impedance,
which make it ideal substitute for Zener diode in appli-
cations such as switching power supply, charger and
other adjustable regulators.
The output voltage of AS431 can be set to any value
between V
REF
(2.5V) and the corresponding maximum
cathode voltage (36V).
The AS431 precision reference is offered in two volt-
age 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.
AS431
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 Coeffi-
cient with 20PPM/
o
C Typical
Sink Current Capacity from 1mA to 100mA
Low Output Noise
Wide Operating Range of -40 to 125
o
C
Applications
·
·
·
·
·
Charger
Voltage Adapter
Switching Power Supply
Graphic Card
Precision Voltage Reference
SOT-89
TO-92(Bulk Packing)
TO-92(Ammo Packing)
SOT-23
SOT-23-5
Figure 1. Package Types of AS431
Dec. 2012 Rev. 2. 6
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BCD Semiconductor Manufacturing Limited
Data Sheet
ADJUSTABLE PRECISION SHUNT REGULATORS
Pin Configuration
N Package
(SOT-23)
ANODE
AS431
R Package
(SOT-89)
K Package
(SOT-23-5)
3
NC
1
2
3
5
ANODE
(Note 1)
*
1
REF
2
CATHODE
1
2
3
CATHODE
4
REF
REF ANODE CATHODE
Note 1:
*
Pin 2 is attached to substrate and
must be connected to ANODE or open
Z Package
(TO-92(Bulk Packing))
Z Package
(TO-92(Ammo Packing))
3
2
1
CATHODE
ANODE
REF
3
2
1
CATHODE
ANODE
REF
Figure 2. Pin Configuration of AS431 (Top View)
Functional Block Diagram
CATHODE
REF
+
-
V
REF
ANODE
Figure 3. Functional Block Diagram of AS431
Dec. 2012 Rev. 2. 6
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BCD Semiconductor Manufacturing Limited
Data Sheet
ADJUSTABLE PRECISION SHUNT REGULATORS
Ordering Information
AS431
Circuit Type
Voltage Tolerance
A: 0.5%
B: 1.0%
Package
N: SOT-23
R: SOT-89
K: SOT-23-5
Z: TO-92
-
E1: Lead Free
G1: Green
TR: Tape and Reel or Ammo
Blank: Bulk
AS431
Package
Temperature
Range
-40 to 125
o
C
Voltage
Tolerance
0.5%
1.0%
0.5%
1.0%
0.5%
Part Number
Lead Free
AS431ANTR-E1
AS431BNTR-E1
AS431AKTR-E1
AS431BKTR-E1
AS431AZ-E1
AS431AZTR-E1
AS431BZ-E1
AS431BZTR-E1
AS431ARTR-E1
AS431BRTR-E1
Green
AS431ANTR-G1
AS431BNTR-G1
AS431AKTR-G1
AS431BKTR-G1
AS431AZ-G1
AS431AZTR-G1
AS431BZ-G1
AS431BZTR-G1
AS431ARTR-G1
AS431BRTR-G1
Marking ID
Lead Free
EB5
EB6
E6H
E6I
AS431AZ-E1
AS431AZ-E1
AS431BZ-E1
AS431BZ-E1
E43G
E43H
Green
GB5
GB6
G6H
G6I
AS431AZ-G1
AS431AZ-G1
AS431BZ-G1
AS431BZ-G1
G43G
G43H
Packing
Type
Tape & Reel
Tape & Reel
Tape & Reel
Tape & Reel
Bulk
Ammo
Bulk
Ammo
Tape & Reel
Tape & Reel
SOT-23
SOT-23-5
-40 to 125
o
C
TO-92
-40 to 125 C
o
0.5%
1.0%
1.0%
SOT-89
-40 to 125
o
C
0.5%
1.0%
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.
Dec. 2012 Rev. 2. 6
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BCD Semiconductor Manufacturing Limited
Data Sheet
ADJUSTABLE PRECISION SHUNT REGULATORS
Absolute Maximum Ratings (Note 2)
Parameter
Cathode Voltage
Cathode Current Range (Continuous)
Reference Input Current Range
Power Dissipation
Junction Temperature
Storage Temperature Range
ESD (Human Body Model)
Symbol
V
KA
I
KA
I
REF
P
D
T
J
T
STG
ESD
Value
40
-100 to 150
10
Z, R Package: 770
mW
N, K Package: 370
150
-65 to 150
2000
o
C
o
C
AS431
Unit
V
mA
mA
V
Note 2: 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
Parameter
Cathode Voltage
Cathode Current
Operating Ambient
Temperature Range
Symbol
V
KA
I
KA
T
A
Min
V
REF
1.0
-40
Max
36
100
125
Unit
V
mA
o
C
Dec. 2012 Rev. 2. 6
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BCD Semiconductor Manufacturing Limited
Data Sheet
ADJUSTABLE PRECISION SHUNT REGULATORS
Electrical Characteristics
Operating Conditions: T
A
=25
o
C, unless otherwise specified.
Parameter
Reference Voltage
0.5%
1.0%
Test
Circuit
4
Symbol
V
REF
Conditions
V
KA
=V
REF,
I
KA
=10mA
0 to 70
o
C
-40 to 85
o
C
-40 to 125
o
C
ΔV
KA
=
10V to V
REF
ΔV
KA
=
36V to 10V
Min
2.487
2.475
Typ
2.500
2.500
4.5
4.5
4.5
-1.0
-0.5
0.7
0.4
0.4
0.05
0.15
135.9
135.9
81.9
29.8
o
AS431
Max
2.512
2.525
8
10
16
-2.7
Unit
V
Deviation of Reference Voltage
Over Full Temperature Range
4
ΔV
REF
V
KA
=V
REF
I
KA
= 10mA
mV
Ratio of Change in Reference
Voltage to the Change in
Cathode Voltage
Reference Current
Deviation of Reference Current
Over Full Temperature Range
Minimum Cathode Current for
Regulation
Off-state Cathode Current
Dynamic Impedance
5
ΔV
REF
ΔV
KA
I
REF
ΔI
REF
I
KA
(Min)
I
KA
(Off)
Z
KA
I
KA
=10mA
mV/V
-2.0
4
1.2
1.0
1.0
0.5
μA
μA
mA
μA
Ω
5
5
4
6
4
I
KA
=10mA,R1=10KΩ, R2=∞
I
KA
=10mA, R1=10KΩ
R2=∞, T
A
=-40 to 125
o
C
V
KA
=V
REF
V
KA
=36V, V
REF
=0
V
KA
=V
REF
, I
KA
=1 to 100mA,
f
≤
1.0KHz
SOT-23
SOT-23-5
TO-92
SOT-89
Thermal Resistance
θ
JC
C/W
Dec. 2012 Rev. 2. 6
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BCD Semiconductor Manufacturing Limited
