Spec. No.
: C502A3
CYStech Electronics Corp. Issued Date : 2003.03.26
Revised Date : 2005.06.29
Page No. : 1/6
Adjustable Precision Shunt Regulators
TL431XA3
Description
The TL431 series are three-terminal adjustable regulators with guaranteed TO-92
thermal stability over applicable temperature ranges. The output voltage
may be set to any value between VREF (approximately 2.495 volts) and 36 volts with two external resistors.
These devices have a typical dynamic output impedance of 0.2Ω. Active output circuitry provides a very
sharp turn-on characteristic, making these devices excellent replacement for zener diodes in many
applications.
Features
• Programmable output voltage
• Temperature coefficient is 50ppm/°C typical
• Temperature compensated for operation over
• full temperature range
• Low output noise voltage
• Fast turn on response
• Pb-free package
Classification
Rank A B C
VREF 2.495±0.5% 2.495±1% 2.495±2%
Absolute Maximum Ratings
(Operating temperature range applies unless otherwise specified)
Characteristics Symbol Value Unit
Cathode Voltage VKA 37 V
Cathode Current Range (Continuous) IK -100~+150 mA
Reference Input Current Range IREF 0.05~+10 mA
Power Dissipation PD 770 mW
Operating Temperature Range Topr 0~+70 °C
Storage Temperature Range Tstg -65~+150 °C
TL431A3 CYStek Product Specification
Spec. No. : C502A3
CYStech Electronics Corp. Issued Date : 2003.03.26
Revised Date : 2005.06.29
Page No. : 2/6
Functional Block Diagram & Symbol
Functional Block Diagram : Symbol :
Cathode
Cathode
Reference +
- Reference
VREF
Anode
Anode
Test Circuits
II II
IN VZ IN VZ IN VZ
IREF R1
IREF
IZ
IZ
VREF
R2 VREF
Fig1. Test Circuit for VZ=VREF Fig 2. Test Circuit for VZ>VREF Fig3. Test Circuit for Off-State
Note : VZ=VREF(1+R1/R2)+IREFxR1 Current
Electrical Characteristics ( Ta=25°C unless otherwise specified )
Characteristics Symbol Test Conditions Min Typ Max Unit
Reference Input Voltage TL431A 2.445 2.495 2.545
TL431B VREF VKA=VREF, IK=10mA 2.470 2.495 2.520 V
TL431C 2.480 2.495 2.510
Deviation of Reference Input Voltage V =V , I =10mA
VREF(dev) KA REF K - 4 17 mV
Over-Temperature Tmin≤Ta≤Tmax
IK=10mA,
Ratio of Change in Reference Input - -1.4 -2.7 mV
∆VREF / ∆VKA=10V-VREF
Voltage to the Change in Cathode
∆VKA IK=10mA,
Voltage - -1.0 -2.0 V
∆KKA=36V-10V
IK=10mA, R1=10kΩ,
Reference Input Current IREF - 2 4 µA
R2=∞
Deviation of Reference Input Current I =10mA, R1=10kΩ,
IREF(dev) K - 0.4 1.2 µA
Over Full Temperature Range R2=∞, Ta=Full Range
Minimum Cathode Current for
IK(min) VKA=VREF - 0.4 1.0 mA
Regulation
Off-State Cathode Current IK(off) VKA=36V, VREF=0 - 0.1 1.0 µA
VKA=VREF, f≤1.0KHz
Dynamic impedance ZKA - 0.2 0.5 Ω
IK=1 to 100mA
TL431A3 CYStek Product Specification
Spec. No. : C502A3
CYStech Electronics Corp. Issued Date : 2003.03.26
Revised Date : 2005.06.29
Page No. : 3/6
Characteristic Curves
CATHODE CURRENT vs
CATHODE VOLTAGE CATHODE CURRENT vs
CATHODE VOLTAGE
150 800
IK - COTHODE CURRENT (uA)
700
IK - COTHODE CURRENT (mA)
125
600
100
500
75
400
50
300
25
200
0
100
-25
0
-50
-100
-75
-200
-100
-1 -0.5 0 0.5 1 1.5 2 2.5 3
-1.5 -1 -0.5 0 0.5 1 1.5 2 2.5
VAK - CATHODE VOLTAGE (V)
VAK - CATHODE VOLTAGE (V)
REFERENCE INPUT VOLTAGE
REFERENCE INPUT CURRENT
vs AMBIENT TEMPERATURE
vs AMBIENT TEMPERATURE
2.464 350
Vref - REFERENCE INPUT
Vref - REFERENCE INPUT
2.462 300
VOLTAGE (mV)
2.46
CURRENT (nA)
250
2.458 200
2.456 150
2.454 100
2.452 50
2.45 0
0 25 50 75 100 125 0 25 50 75 100 125
AMBIENT TEMPERATURE(℃ ) AMBIENT TEMPERATURE(℃ )
CATHODE VOLTAGE vs REFERENCE
INPUT VOLTAGE DYNAMIC IMPEDANCE vs FREQUENCE
0 100
Z KA - DYNAMIC IMPEDANCE (Ω)
Δ Vref - REFERENCE INPUT
-5
VOLTAGE (mV)
-10 10
-15
-20 1
-25
-30
0.1
0 5 10 15 20 25 30 35 40
1 10 100 1000
VKA - CATHODE VOLTAGE (V)
f - FREQUENCE (KHz)
TL431A3 CYStek Product Specification
Spec. No. : C502A3
CYStech Electronics Corp. Issued Date : 2003.03.26
Revised Date : 2005.06.29
Page No. : 4/6
OPEN-LOOP VOLTAGE GAIN
vs FREQUENCY
40
OPEN-LOOP VOLTAGE GAIN
30
(dB)
20
10
0
1 10 100 1000
F - FREQUENCY (KHz)
TL431A3 CYStek Product Specification
Spec. No. : C502A3
CYStech Electronics Corp. Issued Date : 2003.03.26
Revised Date : 2005.06.29
Page No. : 5/6
TO-92 Taping Outline
H2A H2A D2
H2 H2
A
H3
H4 H
L
L1
W1
H1
W
D1 D
F1F2
T2 P1
T P
T1 P2
Millimeters
DIM Item
Min. Max.
A Component body height 4.33 4.83
D Tape Feed Diameter 3.80 4.20
D1 Lead Diameter 0.36 0.53
D2 Component Body Diameter 4.33 4.83
F1,F2 Component Lead Pitch 2.40 2.90
F1,F2 F1-F2 - ±0.3
H Height Of Seating Plane 15.50 16.50
H1 Feed Hole Location 8.50 9.50
H2 Front To Rear Deflection - 1
H2A Deflection Left Or Right - 1
H3 Component Height - 27
H4 Feed Hole To Bottom Of Component - 21
L Lead Length After Component Removal - 11
L1 Lead Wire Enclosure 2.50 -
P Feed Hole Pitch 12.50 12.90
P1 Center Of Seating Plane Location 5.95 6.75
P2 4 Feed Hole Pitch 50.30 51.30
T Over All Tape Thickness - 0.55
T1 Total Taped Package Thickness - 1.42
T2 Carrier Tape Thickness 0.36 0.68
W Tape Width 17.50 19.00
W1 Adhesive Tape Width 5.00 7.00
- 20 pcs Pitch 253 255
TL431A3 CYStek Product Specification
Spec. No. : C502A3
CYStech Electronics Corp. Issued Date : 2003.03.26
Revised Date : 2005.06.29
Page No. : 6/6
TO-92 Dimension
α2 Marking:
A
B
1 2 3
431
α3
C
D
H G
I α1 Style: Pin 1.Reference 2.Anode 3.Cathode
E
F 3-Lead TO-92 Plastic Package
CYStek Package Code: A3
*: Typical
Inches Millimeters Inches Millimeters
DIM DIM
Min. Max. Min. Max. Min. Max. Min. Max.
A 0.1704 0.1902 4.33 4.83 G 0.0142 0.0220 0.36 0.56
B 0.1704 0.1902 4.33 4.83 H - *0.1000 - *2.54
C 0.5000 - 12.70 - I - *0.0500 - *1.27
D 0.0142 0.0220 0.36 0.56 α1 - *5° - *5°
E - *0.0500 - *1.27 α2 - *2° - *2°
F 0.1323 0.1480 3.36 3.76 α3 - *2° - *2°
Notes: 1.Controlling dimension: millimeters.
2.Maximum lead thickness includes lead finish thickness, and minimum lead thickness is the minimum thickness of base material.
3.If there is any question with packing specification or packing method, please contact your local CYStek sales office.
Material:
• Lead: 42 Alloy ; solder plating
• Mold Compound: Epoxy resin family, flammability solid burning class: UL94V-0
Important Notice:
• All rights are reserved. Reproduction in whole or in part is prohibited without the prior written approval of CYStek.
• CYStek reserves the right to make changes to its products without notice.
• CYStek semiconductor products are not warranted to be suitable for use in Life-Support Applications, or systems.
• CYStek assumes no liability for any consequence of customer product design, infringement of patents, or application assistance.
TL431A3 CYStek Product Specification
