TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2 1 of 14
www.diodes.com April 2012
© Diodes Incorporated
Description
The TL431 and TL432 are three terminal adjustable shunt
regulators offering excellent temperatur e stability and output
current handling capabilit y up to 100mA. The output voltage
may be set to any chose n voltage between 2.5 and 3 6 volts
by selection of two external divider resistors.
The devices can be used as a replacem ent for zener diodes
in many applications requiring an improvement in zener
performance. Diodes’ TL431 has the same electrical
specifications as the industry standard ‘431 and is available
in 2 grades with initial tolerances of 1% and 0.5% for the
A and B grades respectively.
Features
• Temperature range -40 to +125ºC
• Reference Voltage Tolerance at 25°C
• TL431A: 2.495V ± 1.0%
• TL431B: 2.495V ± 0.5%
• Low Output Noise
• 0.2Ω Typical Output Impedance
• Sink Current Capability: 1mA to 100mA
• Adjustable Output Voltage: VREF to 36V
• All devices are:
• Totally Lead-Free & Fully RoHS compli ant
(Notes 1 & 2)
• Halogen and Antimony Free. “ Green” Device
(Note 3)
Applications
• Opto-Coupler Linearisers
• Shunt Regulators
• Improved Zener
• Variable Reference
Pin Assignments
TL431
ANODE
REF
CATHODE 1
3
2
(Top View)
SOT23
ANODE
REF
CATHODE
NC
Leave floating or
connect to pin 5 2
34
5
(Top View)
SOT2
5
ANODE
ANODE
REF
NC
ANODE
ANODE
NC
CATHODE 1
2
3
4
8
7
6
5
(Top View)
SO-8
TL432
ANODE
REF
CATHODE
1
3
2
(Top View)
SOT2
3
Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com/quality/lead_free.html 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.
SO-8 is a future product
TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2 2 of 14
www.diodes.com April 2012
© Diodes Incorporated
Absolute Maximum Ratings (Note 4)
Symbol Parameter Rating Unit
VKA Cathode Voltage 40 V
IKA Continuous Cathode Current 150 mA
IREF Reference Input Current -0.050 to +10 mA
TJ Operating Junction Temperature +150 °C
TST Storage Temperature -55 to +150 °C
PD Power Dissipation (Notes 5, 6) SOT23 330
mW
SOT25 500
SO-8* 700
Notes: 4. Operation above the absolute maximum rating may cause device failure. Operation at the absolute maximum ratings, for extended periods, may
reduce device reliability. Unless otherwise stated voltages specified are relative to the ANODE pin.
5. TJ, MAX =150°C.
6. Ratings apply to ambient temperature at 25°C.
Recommended Operating Conditions
Symbol Parameter Min Max Unit
VKA Cathode Voltage VREF 36 V
IKA Cathode Current 1 100 mA
TA Operating Ambient Temperature -40 +125 °C
TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2 3 of 14
www.diodes.com April 2012
© Diodes Incorporated
Electrical Characteristics (TA = +25°C, unless oth erwise noted)
Symbol Parameter Test Conditions Min Typ. Max Unit
VREF Reference voltage VKA = VREF,
IKA = 10mA TL431A 2.470 2.495 2.520
V
TL431B 2.482 2.495 2.507
VDEV Deviation of reference volta ge over
full temperature range (Note 5) VKA = VREF,
IKA = 10mA
TA = 0 to 70oC 6 16
mV
TA = -40 to +85oC 14 34
TA = -40 to +125oC 14 34
ΔVREF
ΔVKA Ratio of the change in reference
voltage to the change in cathode
voltage IKA = 10mA VKA = 10V to VREF -1.4 -2.7
mV/V
VKA = 36V to 10V -1 -2
IREF Reference input current IKA = 10mA, R1 = 10KΩ, R2 = ∞ 1 4 µA
ΔIREF IREF deviation over full temperature
range (Note 7)
IKA = 10mA,
R1 = 10KΩ,
R2 = ∞
TA = 0 to 70oC 0.8 1.2
µA
TA = -40 to +85oC 0.8 2.5
TA = -40 to +125oC 0.8 2.5
IKA(MIN) Minimum cathode current for
regulation VKA = VREF 0.4 0.7 mA
IKA(OFF) Off-state current VKA = 36V, VREF = 0V 0.05 0.5 µA
|ZKA| Dynamic output impedance (Note 8) VKA = VREF, f = 0Hz 0.2 0.5 Ω
θJA Thermal Resistance Junction to
Ambient
SOT23 380
oC/W SOT25 250
SO-8* 70
Notes: 7. Deviation of VDEV, and ΔIREF are defined as the maximum variation of the values over the full temperature range.
The average temperature coefficient of the reference input voltage αVREF is defined as:
Where:
T2 – T1 = full temperature change.
αVREF can be positive or negative depending on whether the slope is
positive or negative.
Notes: 8. The dynamic output impedance, RZ, is defined as:
When the device is programmed with two external resistors R1 and R2, the dynamic output
impedance of the overall circuit, is defined as:
=T2 – T1
αV
REF
V
DEV
V
REF
@ 25ºC X 10
6
ppm/ºC
=T2 – T1
αV
REF
V
DEV
V
REF
@ 25ºC X 10
6
ppm/ºC
Vmax
Vmin
T1 T2
V
DEV
= Vmax - Vmin
Temperature
Vmax
Vmin
T1 T2
V
DEV
= Vmax - Vmin
Temperature
=
Z
KA
ΔV
KA
ΔI
KA
=
Z
KA
ΔV
KA
ΔI
KA
=
Z’ ΔV
ΔIZ
KA
1 + R1
R2
≈
=
Z’ ΔV
ΔI
=
Z’ ΔV
ΔIZ
KA
1 + R1
R2
Z
KA
1 + R1
R2
≈
TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2 5 of 14
www.diodes.com April 2012
© Diodes Incorporated
Typical Performance Characteristics
2400
2420
2440
2460
2480
2500
2520
2540
2560
2580
2600
-55 -35 -15 5 25 45 65 85 105 125
T Free Air Temperature ( C)
Reference Vol tage vs. Free Air Temperature
A
°
V Reference Voltage (mV)
REF
I = 10mA
V = V
T = 25C
KA
KA REF
A
°
0
0.05
0.1
0.15
0.
2
-55 -35 -15 5 25 45 65 85 105 125
T Free Air Temperature ( C)
Reference Current vs. Free Air Tem perature
A
°
I Reference Current ( A)
REF
μ
R1 = 10K
R2 =
I = 10mA
Ω
∞
KA
-100
-50
0
50
100
150
-2 -1 0 1 2 3
V Cathode Voltage (V)
Cathode Current vs. Cathode Voltage
KA
I Cathode Current (mA)
KA
V = V
T = 25C
KA REF
A
°
-100
0
100
200
-2 -1 0123
V Cathode Voltage
Cathode Current vs . Cathode Voltage
KA
I
KMIN
I Cathode Current ( A)
KA
μ
V = V
T = 25C
KA REF
A
°
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.5
0
-75 -50 -25 0 25 50 75 100 125
T Free Air Temperature ( C)
Off-State Cathode Current vs. Free Ai r Temperature
A
°
I Off-S tate Cathode Current ( A)
KOFF
μ
V = 36V
V= 0
KA
REF
-1.0
-0.9
-0.8
-0.7
-0.6
-0.5
-0.4
-0.3
-0.2
-50 -25 0 25 50 75 100 125
V = 3V to 36V
KA
T Free Air Temperature (C)
Ratio of Delta Reference Voltage to Delta Cathode
Voltage vs. Free Ai r Temperature
A
dV /dV (mV/V)
REF KA
TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2 6 of 14
www.diodes.com April 2012
© Diodes Incorporated
Typical Performance Characteristics (cont.)
200
220
240
260
280
300
320
340
360
380
40
0
10 100 1K 10K 100K
f- Frequency (Hz)
Equivalent Input Noise Voltage vs . Frequency
V = Equivalent Input Noise Vol tage nV/ Hz
N
√
I = 10m A
V = V
T = 25°C
KA
KA REF
A
-15
-10
-5
0
5
10
1
5
012345678910
Time (Seconds)
Equivalent Input Noise Voltage Over A 10-S Period
Vn - Equivalent Input Noise Voltage - Vμ
I = 10m A
V = V
T = 25C
KA
KA REF
A
°
Figure 4. Test circuit for noise input voltage
TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2 7 of 14
www.diodes.com April 2012
© Diodes Incorporated
Typical Performance Characteristics (cont.)
0
10
20
30
40
50
60
70
100 1K 10K 100K 1M 10M
f Fr equency (Hz)
Smal l-Signal Voltage Ampli fi cation vs. Frequency
A Small-Signal Vo ltage Amplifi cation (dB)
V
I = 10m A
T = 25C
KA
A
°
Test circuit for voltage amplification
0.0
0.1
1.0
10.0
100.0
1K 10K 100K 1M 10M
Z Re ferenc e Impe dance ( )
KA
Ω
I = 10mA
T = 25C
KA
A°
f Frequency (Hz)
Referenc e Impedance vs. Frequency
Test circuit for reference impedance
TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2 8 of 14
www.diodes.com April 2012
© Diodes Incorporated
Typical Performance Characteristics (cont.)
0
1
2
3
4
5
6
01 2 345678910
t Time ( s)
Pulse Response
μ
Input and Output Voltage (V)
Output
Input T = 25C
A
°
Test Circuit for Pulse Response
0
10
20
30
40
50
60
70
80
90
100
0.00001 0.0001 0.001 0.01 0.1 1
D
C -Load Capaci tance - uF
Stability Boundary Conditions
L
I - Cathode Current - mA
KA
A V = V
B V = 5V
C V = 10V
D V = 15V
KA REF
KA
KA
KA
Stable
Stable Stable
D
CCB
B
A
10
T = 25C
A
°
Test Circuit for Curve A
Test circuit for curves B, C, D
Test Circuit for Curv es B, C, D
The device is stable under all conditions with a load capacitance not exceeding 50pF. The device is stable under all
conditions with a load ca pacitance between 5nF an d 20nF. The device is stable under all conditions with a load capacitance
exceeding 300nF. With a cathode current not exceeding 5mA, the device is stable with any load capacitance.
TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2 10 of 14
www.diodes.com April 2012
© Diodes Incorporated
Ordering Information
Device Package
Code Packaging
(Note 9)
7” Tape and Reel Ammo Box
Quantity Part Number
Suffix Quantity Part Number
Suffix
TL431A(B)SA-7 SA SOT23 3000/Tape & Reel -7 NA NA
TL431A(B)W5-7 W5 SOT25 3000/Tape & Reel -7 NA NA
TL431A(B)S-13* S SO-8* 2500/Tape & Reel -13 NA NA
TL432A(B)SA-7 SA SOT23 3000/Tape & Reel -7 NA NA
* Suffix “B” denotes TL431B device.
Notes: 9. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at
http://www.diodes.com/datasheets/ap02001.pdf.
TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2 11 of 14
www.diodes.com April 2012
© Diodes Incorporated
Marking Information
(1) SOT23
12
3
XX Y W X
(Top View)
XX : Identification code
W : Week : A~Z : 1~26 week;
X: A~Z : Green
Y:Year0~9
a~z : 27~ 52 week; z represents
52 and 53 week
Device Package Identification Code
TL431ASA SOT23 AA
TL431BSA SOT23 AB
TL432ASA SOT23 BA
TL432BSA SOT23 BB
(2) SOT25
Device Package Identification Code
TL431AW5 SOT25 AA
TL431BW5 SOT25 AB
(3) SO-8*
TL431X
(Top View)
YY WW X X
Part Number
Logo
WW : Week : 01~52; 52
YY : Year : 08, 0 9,10~
XX: Internal Code
8765
1234
represents 52 and 53 week
X: tolerance A = 1%, B = 0.5%
TL431X
(Top View)
YY WW X X
Part Number
Logo
WW : Week : 01~52; 52
YY : Year : 08, 0 9,10~
XX: Internal Code
8765
1234
represents 52 and 53 week
X: tolerance A = 1%, B = 0.5%
TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2 12 of 14
www.diodes.com April 2012
© Diodes Incorporated
Package Outline Dimensions (All Dimensions in mm)
(1) Package type: SOT25
(2) Package Types: SOT23
SOT25
Dim Min Max Typ
A
0.35 0.50 0.38
B1.50 1.70 1.60
C2.70 3.00 2.80
D
⎯
⎯
0.95
H2.90 3.10 3.00
J0.013 0.10 0.05
K
1.00 1.30 1.10
L0.35 0.55 0.40
M0.10 0.20 0.15
N0.70 0.80 0.75
α
0° 8°
⎯
A
ll Dimensions in mm
SOT23
Dim Min Max Typ
A
0.37 0.51 0.40
B1.20 1.40 1.30
C2.30 2.50 2.40
D0.89 1.03 0.915
F0.45 0.60 0.535
G1.78 2.05 1.83
H2.80 3.00 2.90
J0.013 0.10 0.05
K
0.903 1.10 1.00
K1 - - 0.400
L0.45 0.61 0.55
M0.085 0.18 0.11
α
0° 8° -
A
ll Dimensions in mm
A
M
JL
D
B C
H
KN
A
M
JL
D
F
BC
H
K
G
K1
TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2 13 of 14
www.diodes.com April 2012
© Diodes Incorporated
Package Outline Dimensions (All Dimensions in mm)
(3) Package Types: SO-8*
SO-8*
Dim Min Max
A
- 1.75
A
10.10 0.20
A
21.30 1.50
A
30.15 0.25
b0.3 0.5
D4.85 4.95
E5.90 6.10
E1 3.85 3.95
e1.27 Typ
h- 0.35
L0.62 0.82
θ
0° 8°
All Dimensions in mm
Gauge Plane
Seating Plane
Det ail ‘A’
Det ail ‘A’
E
E1
h
L
D
eb
A2
A1
A
45
°
7
°~
9
°
A3
0.254
TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2 14 of 14
www.diodes.com April 2012
© Diodes Incorporated
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