AS431 Description Applications Features Pin Assignments

20 Pages·2017·0.54 MB·English

by  Diodes Incorporated

AS431

ADJUSTABLE PRECISION SHUNT REGULATORS

Description Pin Assignments

The AS431 is a three-terminal adjustable shunt regulator with
guaranteed thermal stability over a full operation range. It features (Top View) (Top View)
sharp turn-on characteristics, low temperature coefficient and low ANODE
output impedance, which make it ideal substitute for Zener diode in
3
applications such as switching power supply, charger and other NC 1 5 ANODE

adjustable regulators.

* 2
(Note 4)
The output voltage of AS431 can be set to any value between VREF

(2.5V) and the corresponding maximum cathode voltage (36V). 1 2 CATHODE 3 4 REF

REF CATHODE

The AS431 precision reference is offered in two voltage tolerance:
SOT23 SOT25
0.5% and 1.0%.

Note 4: * Pin 2 is attached to substrate and must be connected to ANODE or
This IC is available in 4 packages: TO92 (Ammo Packing), SOT23,
open.
SOT25 and SOT89.

(Top View) (Top View)
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 1 2 3 1 2 3
 Sink Current Capacity from 1mA to 100mA REF ANODE CATHODE REF ANODE CATHODE
 Low Output Noise SOT89 (Option 1) SOT89 (Option 2)
 Wide Operating Range of -40 to +125°C

 Lead-Free Packages: SOT23, SOT25, TO92 (Ammo Packing), (Top View)
SOT89
 Totally Lead-Free; RoHS Compliant (Notes 1 & 2) 3 CATHODE
 Lead-Free Packages, Available in “Green” Molding Compound:
SOT23, SOT25, TO92 (Ammo Packing), SOT89 2 ANODE
 Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
 Halogen and Antimony Free. “Green” Device (Note 3) 1 REF

TO92 (Ammo Packing)
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) & 2015/863/EU (RoHS 3) compliant.
2. See https://www.diodes.com/quality/lead-free/ 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.

AS431 1 of 20 May 2018
Document number: DS36599 Rev. 4 - 2 www.diodes.com © Diodes Incorporated
AS431

Typical Applications Circuit

Shunt Regulator

High Current Shunt Regulator

Current Source or Current Limit

AS431 2 of 20 May 2018
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AS431

Typical Applications Circuit
(Cont.)

Precision 5V 1A Regulator

PWM Converter with Reference

AS431 3 of 20 May 2018
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AS431

Functional Block Diagram

Absolute Maximum Ratings (Note 5)

Symbol Parameter Rating Unit
VKA Cathode Voltage 40 V
IKA Cathode Current Range (Continuous) -100 to 150 mA
IREF Reference Input Current Range 10 mA
Z, R Package 770
PD Power Dissipation mW
N, K Package 370
TJ Junction Temperature +150 °C
TSTG Storage Temperature Range -65 to +150 °C
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.

Recommended Operating Conditions

Symbol Parameter Min Max Unit
VKA Cathode Voltage VREF 36 V
IKA Cathode Current 1.0 100 mA
TA Operating Ambient Temperature Range -40 +125 °C

AS431 4 of 20 May 2018
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AS431

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

Test
Symbol Parameter Conditions Min Typ Max Unit
Circuit
0.5% 2.487 2.500 2.512
VREF Reference Voltage 4 VKA = VREF, IKA = 10mA V
1.0% 2.475 2.500 2.525
0 to +70°C — 4.5 8
Deviation of Reference Voltage VKA = VREF,
∆VREF Over Full Temperature Range 4 IKA = 10mA -40 to +85°C — 4.5 10 mV
-40 to +125°C — 4.5 16
∆VREF Ratio of Change in Reference ∆VKA = 10V to VREF — -1.0 -2.7
∆VKA Voltage to the Change in Cathode 5 IKA = 10mA mV/V
Voltage ∆VKA = 36V to 10V — -0.5 -2.0
IREF Reference Current 5 IKA = 10mA, R1 = 10kΩ, R2 = ∞ — 0.7 4 µA
∆IREF Deviation of Reference Current 5 IKA = 10mA, R1 = 10kΩ, R2 = ∞, — 0.4 1.2 µA
Over Full Temperature Range TA = -40 to +125°C
(MIKiAn ) MReingiumlautmio nC athode Current for 4 VKA = VREF — 0.4 1.0 mA
IKA Off-state Cathode Current 6 VKA = 36V, VREF = 0 — 0.05 1.0 µA
(Off)
ZKA Dynamic Impedance 4 Vf ≤K A1 =.0 VkHREzF , IKA = 1 to 100mA, — 0.15 0.5 Ω
SOT23 — 135.9 —
SOT25 — 135.9 —
θJC Thermal Resistance — °C/W
TO92 (Ammo Packing) — 81.9 —
SOT89 — 29.8 —

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AS431

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

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AS431

Performance Characteristics

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

2.510 1.5
V = V
KA REF R=10K,R=Infinite
2.50 5 IKA = 10mA IKA1=10mA2
)V )A
( egatloV ecnerefeR 22..4590 50 ( tnerruC ecnerefeR 01..50
2.49 0

2.48 5 0.0
-60 -40 -20 0 20 40 60 80 100 120 140 -60 -40 -20 0 20 40 60 80 100 120 140

Ambient Temperature (oC) Ambient Temperature (0C)

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

150 V =V 800 V =V
KA REF KA REF
T= 250C T=250C
A A
100 600
)Am )A
( tne 50 ( tne 400
rruC ed 0 rruC ed 200
o o
htaC htaC 0
-50
-200
-100
-2 -1 0 1 2 3 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5

Cathode Voltage (V) 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 V =36V -0.9 V =3.5V to 36V
KA KA
)A 1.6 VREF=0
 -1.0
( tn 1.4 )V
erruC ed 11..02 /VmV( AK -1.1
o 
htaC eta 00..68 V/ FER -1.2
tS-ffO 0.4 -1.3
0.2
0.0 -1.4
-40 -20 0 20 40 60 80 100 120 -40 -20 0 20 40 60 80 100 120
Ambient Temperature (oC) Ambient Temperature (oC)

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AS431

Performance Characteristics (Cont.)

Small Signal Voltage Gain vs. Frequency

70

60 TA=250C
I =10mA
50 KA
)B
d( n 40
ia
G e 30
g
atlo 20
V
10

0

-10
1k 10k 100k 1M
Small Signal Frequency (Hz)

Reference Impedance vs. Frequency

I =10mA
KA
T=25oC
) 10 A
( e
c
na
d
ep
m
I e
cn 1
e
re
fe
R

0.1
1K 10K 100K 1,000K

Frequency (Hz)

Stability Boundary Conditions vs. Load Capacitance

100

90

80

)A 70
m
( tn 60 Stable Stable
e
rru 50
C edoh 40 TA=25VoC=V
taC 30 V = 5KVA:NoRE oFscillation
KA
20 V =10V:No oscillation
KA
V =15V:No oscillation
10 KA

0
0.001 0.01 0.1 1 10

Load Capacitance (F)
AS431 8 of 20 May 2018
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AS431

Performance Characteristics (Cont.)

Pulse Response of Input and Output Voltage

5

Input
)V
( eg 4
a
tlo
V
tu 3
p
tu
O
dna 2 Output
tup
n
I 1

0
0 2 4 6
Time (S)

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AS431

Ordering Information

AS431 X X X - X
Product Name Voltage Tolerance Package Packing E1/G1
A : 0.5% N : SOT23 TR : Tape & Reel or E1 : RoHS Compliant
B : 1.0% K : SOT25 Ammo G1 : RoHS Compliant
R : SOT89 and Green
Z : TO92
(Ammo Packing)

RoHS
Voltage Package Compliant Status
Part Number Marking ID Packing Quantity Alternative
Tolerance (Note 7) Lead Free / (Note 6)
Green
Pb AS431ANTR- 0.5% SOT23 Lead Free EB5 Tape & Reel 3000 NRND AS431ANTR
E1 -G1
Lead-Free
Pb AS431BNTR- 1.0% SOT23 Lead Free EB6 Tape & Reel 3000 NRND AS431BNTR
E1 -G1
Lead-Free
AS431ANTR- In
0.5% SOT23 Green GB5 Tape & Reel 3000 —
G1 Production
AS431BNTR- In
1.0% SOT23 Green GB6 Tape & Reel 3000 —
G1 Production
Pb AS431AKTR- AS431AKTR
0.5% SOT25 Lead Free E6H Tape & Reel 3000 NRND
E1 -G1
Lead-Free
Pb AS431BKTR- AS431BKTR
1.0% SOT25 Lead Free E6I Tape & Reel 3000 NRND
Lead-Free E1 -G1
AS431AKTR- In
0.5% SOT25 Green G6H Tape & Reel 3000 —
G1 Production
AS431BKTR- In
1.0% SOT25 Green G6I Tape & Reel 3000 —
G1 Production
Pb AS431AZ- AS431AZTR
AS431AZ-E1 0.5% TO92 Lead Free Bulk 1000 End of Life
Lead-Free E1 -E1
Pb AS431AZTR- AS431AZ- In
0.5% TO92 Lead Free Ammo 2000 —
Lead-Free E1 E1 Production
Pb AS431BZ- AS431BZTR
AS431BZ-E1 1.0% TO92 Lead Free Bulk 1000 End of Life
Lead-Free E1 -E1
Pb AS431BZTR- AS431BZ- In
1.0% TO92 Lead Free Ammo 2000 —
Lead-Free E1 E1 Production
AS431AZ- AS431AZTR
AS431AZ-G1 0.5% TO92 Green Bulk 1000 End of Life
G1 -G1
AS431AZTR- AS431AZ- In
0.5% TO92 Green Ammo 2000 —
G1 G1 Production
AS431BZ- AS431BZTR
AS431BZ-G1 1.0% TO92 Green Bulk 1000 End of Life
G1 -G1
AS431BZTR- AS431BZ- In
1.0% TO92 Green Ammo 2000 —
G1 G1 Production

AS431 10 of 20 May 2018
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