Diodes TL432 User Manual
5
3
Description
TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
Pin Assignments
The TL431 and TL432 are three terminal adjustabl e shunt
regulators offering excellent temperature stability and output
current handling capability up to 100mA. The output voltage
may be set to any chosen voltage between 2.5 and 36 volt s
by selection of two external divider resistors.
The devices can be used as a replacement 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: V
• All devices are:
• Totally Lead-Free & Fully RoHS compliant
(Notes 1 & 2)
• Halogen and Antimony Free. “Green” Device
(Note 3)
REF
to 36V
Applications
• Opto-Coupler Linearisers
• Shunt Regulators
• Improved Zener
• Variable Reference
CATHODE
REF
NC
Leave floating or
connect to pin 5
CATHODE
CATHODE
ANODE
ANODE
NC
SO-8 is a future product
REF
CATHODE
TL431
(Top View)
1
2
SOT23
(Top View)
2
3
SOT2
(Top View)
1
2
3
4
SO-8
TL432
(Top View)
1
2
ANODE
3
5
4
3
ANODE
REF
REF
8
ANODE
7
6
ANODE
5
NC
ANODE
SOT2
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.
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2
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April 2012
© Diodes Incorporated
TL431/TL432
Absolute Maximum Ratings (Note 4)
Symbol Parameter Rating Unit
VKA
IKA
I
REF
TJ
TST
PD
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. T
6. Ratings apply to ambient temperature at 25°C.
Recommended Operating Conditions
Symbol Parameter Min Max Unit
VKA
IKA
TA
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2
Cathode Voltage 40 V
Continuous Cathode Current 150 mA
Reference Input Current -0.050 to +10 mA
Operating Junction Temperature +150
Storage Temperature -55 to +150
Power Dissipation (Notes 5, 6)
=150°C.
J, MAX
Cathode Voltage
Cathode Current 1 100 mA
Operating Ambient Temperature -40 +125 °C
ADJUSTABLE PRECISION SHUNT REGULATOR
°
C
°
C
SOT23 330
SOT25 500
SO-8* 700
V
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REF
36 V
mW
April 2012
© Diodes Incorporated
TL431/TL432
Electrical Characteristics (T
Symbol Parameter Test Conditions Min Typ. Max Unit
V
Reference voltage
REF
V
ΔV
ΔV
Deviation of reference voltage over
DEV
full temperature range (Note 5)
Ratio of the change in reference
REF
voltage to the change in cathode
KA
voltage
I
REF
ΔI
I
KA(MIN)
I
KA(OFF)
|ZKA|
θ
Notes: 7. Deviation of V
The average temperature coefficient of the reference input voltage αV
Where:
T2 – T1 = full temperature change.
αV
positive or negative.
Notes: 8. The dynamic output impedance, R
When the device is programmed with two external resistors R1 and R2, the dynamic output
impedance of the overall circuit, is defined as:
Reference input current
I
deviation over full temperature
REF
REF
range (Note 7)
Minimum cathode current for
regulation
Off-state current
Dynamic output impedance (Note 8)
Thermal Resistance Junction to
JA
Ambient
, and ΔI
DEV
can be positive or negative depending on whether the slope is
REF
Z’
Z’
Z’
=
=
=
are defined as the maximum variation of the values over the full temperature range.
REF
αV
αV
=
=
REF
REF
ΔV
ΔV
ΔV
ΔI
ΔI
ΔI
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2
= +25°C, unless otherwise noted)
A
V
V
DEV
DEV
V
@ 25ºC
V
@ 25ºC
REF
REF
T2 – T1
T2 – T1
Z
ΔV
ΔV
Z
Z
=
=
KA
KA
Z
Z
Z
≈
≈
KA
KA
KA
X 10
X 10
, is defined as:
KA
KA
ΔI
ΔI
KA
KA
R1
R1
R1
1 +
1 +
1 +
R2
R2
R2
ADJUSTABLE PRECISION SHUNT REGULATOR
V
= V
KA
REF
I
= 10mA
KA
VKA = V
I
I
I
I
REF
= 10mA
KA
= 10mA
KA
= 10mA, R1 = 10KΩ, R2 = ∞
KA
= 10mA,
KA
R1 = 10KΩ,
R2 = ∞
VKA = V
REF
VKA = 36V, V
VKA = V
REF,
SOT23 380
SO-8* 70
6
6
ppm/ºC
ppm/ºC
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TL431A 2.470 2.495 2.520
,
TL431B 2.482 2.495 2.507
= 0 to 70oC
T
,
A
TA = -40 to +85oC
TA = -40 to +125oC
V
KA
VKA = 36V to 10V
= 10V to V
REF
6 16
14 34
14 34
-1.4 -2.7
-1 -2
1 4 µA
= 0 to 70oC
T
A
TA = -40 to +85oC
TA = -40 to +125oC
= 0V
REF
f = 0Hz
is defined as:
REF
Vmax
Vmax
Vmin
Vmin
0.8 1.2
0.8 2.5
0.8 2.5
0.4 0.7 mA
0.05 0.5 µA
0.2 0.5 Ω
V
V
= Vmax - Vmin
= Vmax - Vmin
DEV
DEV
T1 T2
T1 T2
Temperature
Temperature
© Diodes Incorporated
April 2012
V
mV
mV/V
µA
o
C/W SOT25 250
Test Circuits
ADJUSTABLE PRECISION SHUNT REGULATOR
Figure 1. Test circuit for VKA = V
TL431/TL432
REF
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2
Figure 2. Test circuit for VKA > V
Figure 3. Test circuit for I
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OFF
REF
April 2012
© Diodes Incorporated
2
0
Typical Performance Characteristics
2600
2580
2560
2540
2520
I = 10mA
KA
V = V
KA REF
T = 25C
A
TL431/TL432
ADJUSTABLE PRECISION SHUNT REGULATOR
0.
R1 = 10K
Ω
R2 =
°
0.15
μ
∞
I = 10mA
KA
2500
2480
2460
REF
V Reference Voltage (mV)
2440
2420
2400
-55 -35 -15 5 25 45 65 85 105 125
T Free Air Temperature ( C)
A
Reference Voltage vs. Free Air Temperature
150
V = V
KA REF
T = 25C
°
A
100
50
0
KA
I Cathode Current (mA)
-50
0.1
REF
0.05
I Reference Current ( A)
0
-55 -35 -15 5 25 45 65 85 105 125
°
T Free Air Temperature ( C)
A
°
Reference Current vs. Free Air T e m perature
200
V = V
KA REF
T = 25C
°
A
μ
100
I
KMIN
0
KA
I Cathode Current ( A)
-100
-2 -1 0 1 2 3
V Cathode Voltage (V)
KA
Cathode Current vs. Cathode Voltage
0.5
V = 36V
KA
V= 0
0.45
REF
μ
0.40
-100
-2 -1
-0.2
-0.3
-0.4
0
V Cathode Voltage
KA
12
Cathode Current vs. Cathode Voltage
V = 3V to 36V
KA
3
0.35
0.30
0.25
0.20
0.15
0.10
KOFF
I Off-State Cathode Current ( A)
-0.5
-0.6
REF KA
-0.7
dV /dV (mV/V)
-0.8
-0.9
0.05
0.00
-75
-50 -25 0 25 50
T Free Air Temperature ( C)
A
75
°
100 125
Off-State Cathode Current vs. Free Air Temperature
TL431 *SO-8 is a future package
Document number: DS35044 Rev. 6 - 2
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-1.0
-50 -25 0 25 50 75 100 125
Ratio of Delta Reference Voltage to Delta Cathode
T Free Air Temperature (C)
A
Voltage vs. Free Air Temperature
© Diodes Incorporated
April 2012
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