Adjustable Precision Shunt
Voltage Regulator
LA431A LA431B
Adjustable Precision Shunt Regulator
General Description
• LA431A and LA431B are three terminal Adjustable PrecisionShunt Regulators,
With guaranteed thermal stability over a full operation temperature range.
• The output Voltage of these ICs can be set to any value between VREF (Typical 2.50V)
and the corresponding maximum cathode voltage with two external resistors.
• These devices feature the sharp turn-on characteristics,low temperature coefficient
and low output impedance, making them ideal substitute for Zener Diode in many
applications such as switching power supplly, charger and other adjustable regulators.
TO-92
(Bulk)
TO-92
(Ammo)
• LA431 precision reference Voltage tolerance is offered in 2 grades:0.8% for LA431A
and 0.4% for LA431B
• Both LA431A and LA431B are available in TO-92 (Bulk), TO-92 (Ammo),SOT-89,
SOT-23 and SOT-23-5 packages.
SOT-89
.Features
•
•
•
•
•
•
•
•
•
Programmable Precise Output Voltage:2.50V to 18V
High Stability under Capacitive Load
Wide Operation Temperature Range:-40°C to 125°C
Low Temperature Deviation:4.5mV (Typical)
Low Equivalent Full-range Temperature Coefficient :20ppm/°C (Typical)
Sink Current Capacity:1mA to100mA
Low Dynamic Output Rresitance:0.20Ω (Typical)
Low Output Noise
RoHS Compliance and Halogen Free
SOT-23
SOT-23-5
Applications
•
•
•
•
•
Switching Power Supply
Charger
Voltage Adapter
Graphic Card
Precision Voltage Reference
TAITRON COMPONENTS INCORPORATED www.taitroncomponents.com
Tel:
Fax:
(800)-TAITRON (800)-824-8766
(800)-TAITFAX (800)-824-8329
(661)-257-6060
(661)-257-6415
Rev. A/LX
Page 1 of 14
Adjustable Precision Shunt Voltage Regulator
LA431A LA431B
Ordering Information
Pin Configuration
1: REF 2: ANODE
3: CATHODE
TO-92(Bulk)
1: REF
2: CATHODE 3: ANODE
SOT-23
1: REF 2: ANODE
3: CATHODE
1: REF 2: ANODE
TO-92(Ammo)
3: CATHODE
SOT-89
1:NC 2:NC
3: CATHODE 4: REF 5: ANODE
SOT-23-5
Rev. A/LX
www.taitroncomponents.com
Page 2 of {14
Adjustable Precision Shunt Voltage Regulator
LA431A LA431B
Functional Block Diagram
Marking information
Outline
Temperatue
Range
VREF
Tolerance
LA431AZ-08-AG
LA431AZ-08-BL
LA431AZ-08-BG
LA431BZ-08-AR
LA431BZ-08-AG
LA431BZ-08-BL
LA431BZ-08-BG
0.8%
LA431AK-08-TR70
0.4%
AZ431BZ-BG1
AZ431AZ-BE1
AZ431AZ-BG1
LA431AK-08-RG70
E43D
G43D
LA431BK-08-TR70
LA431BK-08-RG70
E43C
G43C
0.8%
LA431AN-08-TR70
LA431AN-08-RG70
EA5
GA5
0.4%
LA431BN-08-TR70
LA431BN-08-RG70
EA4
GA4
0.8%
LA431AN5-08-TR70
LA431AN5-08-RG70
E4B
G4B
0.4%
LA431BN5-08-TR70
LA431BN5-08-RG70
E4A
G4A
0.4%
-40 to 125°C
SOT-23
-40 to 125°C
SOT-23
-5
-40 to 125°C
Marking Code
Packing
Halogen Free T Type
RoHS
AZ431BZ-BE1
-40 to 125°C
SOT-89
Part Number
Halogen Free
LA431AZ-08-AR
0.8%
TO-92
RoHS
Ammo
Bulk
Ammo
Bulk
Tape
& Reel
Tape
& Reel
Tape
& Reel
Rev. A/LX
www.taitroncomponents.com
Page 3 of {14
Adjustable Precision Shunt Voltage Regulator
LA431A LA431B
Absolute Maximum Ratings (Note1)
Symbol
Description
Ratings
Unit
VKA
IKA
IREF
Cathode Voltage
Continuous Cathode Current
Reference Input Current
Z:TO-92
Power
K: SOT-89
Dissipation
N:SOT-23
N5:SOT-23-5
Junction Temperature
Storage Temperature Range
ESD
20
-100 to 150
10
V
mA
mA
PD
TJ
TSTG
ESD(Human body model)
770
mW
370
150
-65 to 150
2000
°C
°C
V
Recommend Operating Ratings(Note1)
Symbol
Description
VKA
IKA
TA
Cathode Voltage
Continuous Cathode Current
Operating Ambient Temperatrue
Ratings
Min
Max
18
VREF
1.0
100
-40
125
Unit
V
mA
°C
Note1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.Recommend
Opertaing ratings indicate conditions for which the devices is functional,but do not guarantee specific specifation
limits. For guarantee specifation and test conditions,see the Electrical Charctristics, the guarantee specifation
apply only for the test conditions listed.Some performance characteristics may degrade when the device is not
operated under the listed test conditions.
Electrical Characteristics (TA=25°C, unless otherwise specified)
Symbol
VREF
Description
Reference
Voltage
0.4%
0.8%
Min.
Typ.
Max.
Unit
Test
Circuit
Test Conditions
2.490
2.480
-
2.500
2.500
4.5
4.5
4.5
2.510
2.520
8
10
16
V
V
Fig.1
VKA=VREF,IKA=10mA
-1.0
-2.7
-0.5
-2.0
0.7
4.0
∆ VREF
Deviation of Reference Voltage
Over Full Temperature Range
∆ VREF
∆ VKA
Ratio of change in Reference
Voltage to the change in
Cathode Voltage
-
Reference Current
-
IREF
mV
Fig.1
mV/ V
Fig.2
uA
Fig.2
0°C to 70°C
VKA=VREF
-40°C to 85°C
IKA=10mA
-40°C to125°C
∆ VKA= VREF
to 10V
IKA=10mA
∆ VKA= 10V to
18V
IKA=10mA,R1=10KΩ,R2=∞
Rev. A/LX
www.taitroncomponents.com
Page 4 of {14
Adjustable Precision Shunt Voltage Regulator
LA431A LA431B
∆ IREF
IKA(Min)
IKA(Off)
ZKA
Deviation of Reference Current
Over Full Temperature Range
-
0.4
1.2
uA
Fig.2
IKA=10mA, R1=10KΩ,R2=∞
TA =-40°C to125°C
Minimum Cathode Current for
Regulation
Off-state Cathode Current
-
0.4
1.0
mA
Fig.1
VKA=VREF
-
0.05
1.0
uA
Fig.3
Dynamic Impedance
-
0.2
0.5
Ω
Fig.1
Thermal Resisitance
-
107.04
111.03
177.65
177.65
° C/W
-
VKA=18V, VREF=0V
VKA=VREF, IKA=1mA to
100mA,f≤1.0KHz
Z:TO-92
K: SOT-89
N:SOT-23
N5:SOT-23-5
Parameter Test Circuit
Fig.1 Test Circuit for VKA=VREF
Fig.2 Test Circuit for VKA>VREF
Fig.3 Test Circuit for IKA(Off)
Rev. A/LX
www.taitroncomponents.com
Page 5 of {14
Adjustable Precision Shunt Voltage Regulator
LA431A LA431B
Typical Characteristics Curves
Fig.4 VREF-TA
Fig.5 IREF-TA
R1=10K Ω
Reference Current IREF (uA)
Reference Voltage VREF (V)
VKA=VREF
IKA=10mA
Operation Ambient Temperature TA (° C)
R2= ∞
IKA=10mA
Operation Ambient Temperature TA (° C)
VKA=VREF
TA=25 ° C
Cathode Voltage VKA (V)
Fig.7 IKA-VKA
Cathode Current IKA (uA)
Cathode Current IKA (mA)
Fig.6 IKA-VKA
VKA=VREF
TA=25 ° C
Cathode Voltage VKA (V)
Rev. A/LX
www.taitroncomponents.com
Page 6 of {14
Adjustable Precision Shunt Voltage Regulator
LA431A LA431B
Fig.9
Ratio of change in Reference Voltage
to the change in Cathode Voltage
(mV/V)
Off-State Cathode Current IKA (off) (uA)
( A)
Fig.8 IKA(Off)-TA
VKA=18V
VREF=0V
Operation Ambient Temperature TA (° C)
∆ VREF -TA
∆ VKA
VKA=3.5V to 18V
Operation Ambient Temperature TA (° C)
Cathode Current IKA (mA)
Fig.10 IKA-CLOAD
VKA=10V :No Oscillation
VKA=15V :No Oscillation
Stable
Stable
VKA=VREF
VKA=5V
Load Capacitance CLOAD (uF)
Rev. A/LX
www.taitroncomponents.com
Page 7 of {14
Adjustable Precision Shunt Voltage Regulator
LA431A LA431B
Fig.11 VG-f
Voltage Gain VG (dB)
TA=25 ° C
IKA=10mA
Small Signal Frequency f (Hz)
Reference Impedance (Ω)
Fig.12 ZKA-f
TA=25 ° C
IKA=10mA
Frequency f (Hz)
Rev. A/LX
www.taitroncomponents.com
Page 8 of {14
Adjustable Precision Shunt Voltage Regulator
LA431A LA431B
Output and Input Voltage VOUT/VIN (V)
Fig.13 Pulse Respond of Input and Output Voltage
Input
Output
Time (uS)
Rev. A/LX
www.taitroncomponents.com
Page 9 of {14
Adjustable Precision Shunt Voltage Regulator
LA431A LA431B
Typical Application Circuit
Fig.14 Shunt Regulator
Fig.16 Current Source or Current Limit
Fig.15 High Current Shunt Regulator
Fig.17 Precision 5V 1A Regulator
Fig.18 PWM Converter With Reference
Rev. A/LX
www.taitroncomponents.com
Page 10 of
Adjustable Precision Shunt Voltage Regulator
LA431A LA431B
Dimensions in mm (inch)
TO-92 Buck
TO-92 Ammo
Rev. A/LX
www.taitroncomponents.com
Page 11 of
Adjustable Precision Shunt Voltage Regulator
LA431A LA431B
SOT-89
SOT-89
Rev. A/LX
www.taitroncomponents.com
Page 12 of
Adjustable Precision Shunt Voltage Regulator
LA431A LA431B
SOT-23
SOT-23-5
Rev. A/LX
www.taitroncomponents.com
Page 13 of
Adjustable Precision Shunt Voltage Regulator
LA431A LA431B
How to contact us:
US HEADQUARTERS
28040 WEST HARRISON PARKAWAY, VALENCIA, CA 91355-4162
Tel: (800) TAITRON (800) 824-8766 (661) 257-6060
Fax: (800) TAITFAX (800) 824-8329 (661) 257-6415
Email: [email protected]
Http://www.taitroncomponents.com
TAITRON COMPONENTS MEXICO, S.A .DE C.V.
BOULEVARD CENTRAL 5000 INTERIOR 5 PARQUE INDUSTRIAL ATITALAQUIA, HIDALGO C.P.
42970 MEXICO
Tel: +52-55-5560-1519
Fax: +52-55-5560-2190
TAITRON COMPONETS INCORPORATED E REPRESENTAÇÕES DO BRASIL LTDA
RUA DOMINGOS DE MORAIS, 2777, 2.ANDAR, SALA 24 SAÚDE - SÃO PAULO-SP 04035-001 BRAZIL
Tel: +55-11-5574-7949
Fax: +55-11-5572-0052
TAITRON COMPONETS INCORPORATED, SHANGHAI REPRESENTATIVE OFFICE
METROBANK PLAZA, 1160 WEST YAN’ AN ROAD, SUITE 1503, SHANGHAI, 200052, CHINA
Tel: +86-21-5424-9942
Fax: +86-21-5424-9931
Rev. A/LX
www.taitroncomponents.com
Page 14 of