PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
PROGRAMMABLE PRECISION REFERENCES
The TL431Z is three-terminal adjustable shunt regulator
with specified termal stability.
The output voltage may be set to any value between
V
REF
(Approx. 2.5V) and 36V with two external resistors.
This device has a typical output inpedance of 0.2Ω.
Active output circuitry provides a very sharp turn-on
characteristic, making this device excellent
replacement for zener diodes in many application.
FEATURES
● Equivalent Full Range Temperature Coefficient 50PPM/℃ ORDERING INFORMATION
● Temperature Compensated For Operation Over
Full Rate Operating Temperature Range
● Adjustable Output Voltage
● Fast Turn-on Response
● Sink Current Capability 1㎃ to 100㎃
● Low (0.2Ω Typ.) Dynamic Output Impedance
● Low Output Noise
FUNCTION BLOCK DIAGRAM
Jan. 2007 - Rev 1.0 HTC
Package
TO-92
Device Marking
TL431Z
TL431-AZ
TL431Z
TL431-AZ
TL431-CZTL431-CZ
TL431-AZSF
TL431-CZSF
SOT-23
431
TL431ZSF
1
2.5VREF
BLOCK DIAGRAM
REFERENCE CATHODE
ANODE
REFERENCE(R)
ANODE(A)
CATHODE(K)
* Packing label is
different as Vref
3
.
Cathode
2.Anode
1.Reference
2.Anode
1.Reference 3.Cathode
TO-92 PKG
SOT-23 PKG
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
E
Q
UIVALENT SCHEMATIC
- All component values are nominal
RECOMMENDED OPERATING CONDITIONS
DISSIPATION RATING TABLE1-FREE-AIR TEMPERATURE
Jan. 2007 - Rev 1.0 HTC
491㎽6.2㎽/℃
36
100
MIN.
V
㎃
TA=70℃
Power Rating
TA=85℃
Power Rating
VREF
1
TA=125℃
Power Rating
-398㎽ TO-92
2
Power Rating
Derating Factor
Above TA=25℃
UNITMAX.CHARACTERISTIC
Cathode Voltage
Cathode Current
SYMBOL
VKA
IK
770㎽
Package TA=25℃
122㎽ - SOT-23 230㎽ 1.8㎽/℃ 149㎽
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
ABSOLUTE MAXIMUM RATINGS
(Full Operating Ambient Temperature Range Applies Unless Otherwise Noted)
CHARACTERISTIC
Cathode Voltage
Continuous Cathode Current Range
Reference Input Current Range
Junction Temperature
Operating Temperature
Storage Temperature
TO-92 PKG = 178
TL431Z ELECTRICAL CHARACTERISTICS (TA=25℃, unless otherwise specified)
Reference Input Voltage VKA=VREF, IK=10㎃
Deviation of Reference VKA=VREF, IK=10㎃
Input Voltage Over TA=Full Range
Full Temperature Range
Ratio of Change in
Reference Input Voltage
to the Change in Cathod
Voltage
Reference Input Current IKA=10㎃, R1=10㏀, R2=∞
Deviation of Reference IK=10㎃, R1=10㏀, R2=∞
Input Current Over Full TA=Full Range
Temperature Range
Minimum Cathode ΔVKA=VREF
Current for Regulation
Off-State Cathode VKA=36V, VREF=0
Current
Dynamic Impedance VKA=VREF, IK=1㎃~100㎃,
f≤1㎑
Jan. 2007 - Rev 1.0 HTC
IREF 2
TSTG -65 ~ 150
Thermal Resistance Junction to Ambient ΘJA
IK=10㎃
ΔVKA=10V-VREF
2
CHARACTERISTIC CIR-CUITSYMBOL
1
2.495
TEST CONDITION
TOPR
ZKA 1
1
1
VREF
ΔVREF/ΔT
ΔVREF
/ΔVKA
ΔVKA=36V-10V
2
㎂
㎂
-1
0.4
-1.4 -2.7
㎂0.1
0.2 0.5 Ω
1.2
ΔIREF/ΔT
IKAMIN
IKAOFF 3
0.4 1 ㎃
℃
℃
℃
㎷/V
VKA
IKA
V
㎃
2.550
2.0 4
1
㎷317
IREF
TJ150
℃/W
SOT-23 PKG = 625
-2
SYMBOL
V
RATING
37
-100 ~ +150
2 ~ 4 ㎂
MIN.
-40 ~ 85
2.440
UNITTYP. MAX.
UNIT
3
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
TL431AZ ELECTRICAL CHARACTERISTICS (TA=25℃, unless otherwise specified)
Reference Input Voltage VKA=VREF, IK=10㎃
Deviation of Reference VKA=VREF, IK=10㎃
Input Voltage Over TA=Full Range
Full Temperature Range
Ratio of Change in
Reference Input Voltage
to the Change in Cathod
Voltage
Reference Input Current IKA=10㎃, R1=10㏀, R2=∞
Deviation of Reference IK=10㎃, R1=10㏀, R2=∞
Input Current Over Full TA=Full Range
Temperature Range
Minimum Cathode ΔVKA=VREF
Current for Regulation
Off-State Cathode VKA=36V, VREF=0
Current
Dynamic Impedance VKA=VREF, IK=1㎃~100㎃,
f≤1㎑
TL431CZ ELECTRICAL CHARACTERISTICS (TA=25℃, unless otherwise specified)
Reference Input Voltage VKA=VREF, IK=10㎃
Deviation of Reference VKA=VREF, IK=10㎃
Input Voltage Over TA=Full Range
Full Temperature Range
Ratio of Change in
Reference Input Voltage
to the Change in Cathod
Voltage
Reference Input Current IKA=10㎃, R1=10㏀, R2=∞
Deviation of Reference IK=10㎃, R1=10㏀, R2=∞
Input Current Over Full TA=Full Range
Temperature Range
Minimum Cathode ΔVKA=VREF
Current for Regulation
Off-State Cathode VKA=36V, VREF=0
Current
Dynamic Impedance VKA=VREF, IK=1㎃~100㎃,
f≤1㎑
Jan. 2007 - Rev 1.0 HTC
MIN. TYP. MAX. UNITCHARACTERISTIC SYMBOL CIR-CUIT TEST CONDITION
1317
VREF 1 2.470 2.495 V
㎷
-1.4 -2.7
2 2.0
ΔVREF
/ΔVKA 2 IK=10㎃
ΔVKA=10V-VREF
ΔVKA=36V-10V
ΔVREF
/ΔT
1.2
4
-2
2.520
ΔIREF
/ΔT 2 0.4
IREF
㎂
㎂
㎷/V
IKA
MIN 1 0.4 1
IKA
OFF 3 0.1 1
1 0.2 0.5
㎃
㎂
Ω
UNITCHARACTERISTIC SYMBOL CIR-CUIT TEST CONDITION
ZKA
㎷
VREF 1 2.482 2.495
ΔVREF
/ΔT 1317
ΔVREF
/ΔVKA 2 IK=10㎃
ΔVKA=10V-VREF
ΔVKA=36V-10V
IREF 2
㎷/V
-1 -2
-1.4 -2.7
ΔIREF
/ΔT 2 0.4 1.2
㎂
IKA
MIN 1 0.4 1
IKA
OFF 3 0.1 1
㎃
Ω
4㎂
㎂
2.508 V
ZKA 1 0.2 0.5
2.0
MIN. TYP. MAX.
-1
4
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
Fig. 1 Test Circuit for V KA=VREF Fig. 2 Test Circuit for V KA≥VREF
Fig. ３ Test Circuit for IKA（off)
Jan. 2007 - Rev 1.0 HTC
5
INPUT VKA
IKA
VREF
DUT
IKA
DUT
VKA
INPUT
INPUT VKA
IKA
VREF
DUT
ＩREF
VKA
=VREF
(1+R1/R2)+IREF
R1
R1
R2
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
The deviation parameters VREF(DEV)
and IREF(DEF)
are defined as the differences between the maximum and minimum
values obtained over the recommended temperature range. The average full-range temperature coefficient of the
reference voltage, αV REF, is defined as :
Where :
ΔTA is the recommended operating free-air temperature range of the device.
αVREF can be positive or negative, depending on whether minimum V REF or maximum VREF, respectively, occurs at the
lower temperature.
Example : Maximum VREF=2496㎷ at 30℃, maximum VREF=2492㎷ at 0℃, VREF=2495㎷ at 25℃, ΔTA=70℃
for TL431CZ
Because minimum VREF occurs at the lower temperature, the coefficient is positive.
Calculating Dynamic Impedance
The dynamic impedance is defined as :
When the device is operating with two external resistors (see Figure 3), the total dynamic impedance of the circuit
is given by :
Figure 1. Calculating deviation parameters and dynamic impedance
Jan. 2007 - Rev 1.0 HTC
6
70℃
4㎷
2495㎷ x106
）（
｜αVREF
｜= ~ 23PPM/℃
x106
VI(dev)
VREF
at 25℃）（
｜αVREF
｜
ΔTA
ppm
℃ =）
（
ΔV
ΔI （1+ ）
R1
R2
｜Z'｜= ~｜ZKA
｜
ΔVKA
ΔIKA
｜ZKA
｜=
ΔTA
VI(dev)
Maximum VREF
Minimum VREF
~
~
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
TYPICAL PERFORMANCE CHARACTERISTICS
† Data is applicable only within the recommended operating free-air † Data is applicable only within the recommended operating free-air
temperature ranges of the various devices. temperature ranges of the various devices.
‡ Data is for devices having the indicated value of V
REF
at IKA=10㎷,
TA=25℃
Figure 4. Figure 5.
Figure 6. Figure 7.
Jan. 2007 - Rev 1.0 HTC
7
VREF
-REFERENCE VOLTAGE
-
2400
REFERENCE VOLTAGE vs
FREE-AIR TEMPERATURE†
2420
2440
2460
2480
2500
2520
2540
2560
2580
2600
VREF
=2500㎷‡
VREF
=2495㎷‡
VREF
=2440㎷‡
-75 -50 -25 0 25 50 75 100 125
TA-FREE-AIR TEMPERATURE-℃
VREF
-REFERENCE VOLTAGE
-
0
REFERENCE CURRENT vs
FREE-AIR TEMPERATURE †
1
2
3
4
5
R1=10㏀
R2=∞
IKA
=10㎃
-75 -50 -25 0 25 50 75 100 125
TA-FREE-AIR TEMPERATURE-℃
IKA
-CATHODE CURRENT
-
-100
CATHODE CURRENT vs
CATHODE VOLTAGE
-75
-50
-25
0
25
50
75
100
125
150
VKA
=VREF
TA=25℃
-2 -1 0 1 2 3
VKA
-CATHODE VOLTAGE-V
IKA
-CATHODE CURRENT
-
-200
CATHODE CURRENT vs
CATHODE VOLTAGE
0
200
400
600
800
VKA
=VERF
TA=25℃
-1 0 1 2 3
VKA
-CATHODE VOLTAGE-V
IMIN
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
TYPICAL PERFORMANCE CHARACTERISTICS
† Data is applicable only within the recommended operating free-air † Data is applicable only within the recommended operating free-air
temperature ranges of the various devices. temperature ranges of the various devices.
Figure 8. Figure 9.
Figure 10.
Jan. 2007 - Rev 1.0 HTC
8
IOFF
-OFFSTATE CATHODE CURREN
T
0
OFF-STATE CATHODE CURRENT
vs FREE-AIR TEMPERATURE†
0.5
1
1.5
2
2.5
VKA
=36
V
-75 -50 -25 0 25 50 75 100 125
TA-FREE-AIR TEMPERATURE-℃
ΔV
REF
/ΔV
KA
-㎷/
V
-1.45
RATIO DELTA REFERENCE VOLTAGE TO
DELTA CATHODE VOLTAGE vs
FREE-AIR TEMPERATURE †
-1.25
-1.15
-1.05
-0.95
-0.85
VKA
=3V TO 36V
-75 -50 -25 0 25 50 75 100 125
TA-FREE-AIR TEMPERATURE-℃
VIN-EQUIVALENT NOISE VOLTAGE-㎵
100
EQUIVALENT INPUT NOISE VOLTAGE
VS FREQUENCY
120
140
160
180
200
220
240
260
IO=10㎃
TA=25℃
10 100 1K 10K 100K
f-FREQUENCY-㎐
-1.35
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 11. Test Circuit for Equivalent Input Noise Voltage
Test Circuit for Voltage Amplification
Figure 12.
Jan. 2007 - Rev 1.0 HTC
9
VCC
+
-
+
-
910Ω
500㎌
19.1
V
1㏀
910Ω
820Ω
16Ω
TL431
(DUT)
2000㎌
160㏀
0.1㎌
VEE
16㏀ 16㏀
TL2027
AV=10V/㎷
TO OSCILLOSCOPE
22㎌
TL2027
1㎌
33㏀
33㏀
1㎌
VEE
VCC
AV=2V/V
AV-SMALL-SIGNAL VOLTAGE AMPLIFICATI
O
0
SMALL-SIGNAL VOLTAGE AMPLIFICATION
VS FREQUENCY
10
20
30
40
50
60
IKA
=10㎃
TA=25℃
1K 10K 100K 1M 10M
f-FREQUENCY-㎐
9㎌
~
15㏀
OUTPUT
232Ω
8.25㏀
IKA
GND
+
-
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
TYPICAL PERFORMANCE CHARACTERISTICS
Test Circuit for Reference Impedance
Figure 13.
Test Circuit for Pulse Response
Figure 14.
Jan. 2007 - Rev 1.0 HTC
10
｜ZKA
｜-REFERENCE IMPEDANC
E
0.1
REFERENCE IMPEDANCE
VS FREQUENCY
1
10
100
IKA
=10㎃
TA=25℃
1K 10K 100K 1M 10M
f-FREQUENCY-㎐
1㏀
OUTPUT
50Ω IKA
~
GND
-
+
｜ZKA
｜-REFERENCE IMPEDANC
E
0
REFERENCE IMPEDANCE
VS FREQUENCY
2
5
6
TA=25℃
-1 1 3 5 7
t-TIME-㎲
OUTPUT
50Ω
GND
220Ω
PULSE
GENERATOR
f=100㎑
4
3
1
02
46
INPUT
OUTPUT
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
APPLICATION INFORMATION
NOTE A : R Should provide cathode current≥1㎃ to the TL431 at minimum V
I
(BATT)
Figure 15. Shunt Regulator
Figure 16. Single-Supply Comparator With Temperature-Compensated Threshold
NOTE A : R Should provide cathode current≥1㎃ to the TL431 at minimum V
I
(BATT)
Figure 17. Precision High-Current Series Regulator
Jan. 2007 - Rev 1.0 HTC
11
R
(SEE NOTE A)
VO
TL431
R1
0.1%
R2
0.1%
VO =
（1+ ）
R1
R2 VREF
VREF
VI(BATT)
RETURN
VO
INPUT
VIT
VI(BATT)
GND
TL431
~
~2.5V
VON
VOFF
~
~
~
~
2.5V
VI(BATT)
VO
TL431
2N222
VO =
（1+ ）
R1
R2 VREF
VI(BATT)
R
(SEE NOTE A)
2N222
4.7㏀
R1
0.1%
R2
0.1%
30Ω
0.01㎌
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
APPLICATION INFORMATION
Figure 18. Output Control of a 3-Terminal Fixed Regulator
Figure 19. High-Current Shunt Regulator
NOTE A : Refer to the stability boundary conditions in Figure 16 to determine allowable values for C.
Figure 20. Crowbar Circuit
Jan. 2007 - Rev 1.0
HTC
12
MINIMUM VO=VREF
+5V
VO
LM7805
R1
R2
VO =
（1+ ）
R1
R2 VREF
VI(BATT)
IN
OUT
TL431
COMMON
VO
TL431
R1
R2
（1+ ）
R1
R2
VO =VREF
VI(BATT)
RETURN
VO
TL431
R1
R2
VI(BATT)
C
(SEE NOTE A)
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
APPLICATION INFORMATION
Figure 21. Precision 5-V 1.5A Regulator
NOTE A : R
B
Should provide cathode current≥1㎃ to the TL431.
Figure 22. Efficient 5-V Precision Regulator
Figure 23. PWM Converter With Reference
Jan. 2007 - Rev 1.0
HTC
13
TL431
~
~5V, 1.5A
VO
TL431
VI(BATT)
RB
(SEE NOTE A)
27.4㏁
0.1%
VO
LM317
VI(BATT) IN OUT
8.2㏀ 243Ω
0.1%
243Ω
0.1%
Adjust
~
~5V
27.4㏁
0.1%
TL431
6.8㏁
5V 10㏁
10㏁
0.1%
10㏁
0.1%
-
+
FEED BACK
X
NOT
USED
TL598
12V
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
APPLICATION INFORMATION
NOTE A : R3 and R4 are selected to provide the desired LED intensity and cathode current ≥1㎃
to the TL431 at the available V
Figure 24. Voltage Monitor
Fi
g
ure 25. Dela
y
Timer
Figure 26. Precision Current Limiter
Jan. 2007 - Rev 1.0
HTC
14
TL431
VI(BATT) OUT
R1A R1B
R2B
650Ω
R2A
R3
(SEE NOTE A)
R4
(SEE NOTE A) LOW LIMIT= VREF
R1B
R2B
（1+ ）
HIGH LIMIT= VREF
R1A
R2A
（1+ ）
LED ON WHEN LOW LIMIT＜<VI(BATT)
＜HIGH LIMIT
12V
R
CON
OFF
2㏀
TL431
DELAY=RxCxIN
12V
12V-VREF
(）
TL431
VI(BATT)
IO
RCL
0.1% IOUT
=VREF
RCL + IKA
R1 =VI(BATT)
IO
HFE
+ IKA
R1
PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ
APPLICATION INFORMATION
Figure 27. Precision Constant-Current Sink
Jan. 2007 - Rev 1.0
HTC
15
IO
TL431
VI(BATT)
IO =
RS
0.1%
VREF
RS