TL431 Programmable Precision References
The TL431 integrated circuits are three-terminal programmable shunt regulator diodes. These monolithic IC voltage references operate as a low temperature coefficient zener which is programmable from Vref to 36 volts with two external resistors. These devices exhibit a wide operating current range of 1.0 to 100mA with a typical dynamic impedance of 0.22 Ω . The characteristics of these references make them
excellent replacements for zener diodes in many applications such as digital voltmeters, power supplies, and op amp circuitry. The 2.5 volt reference makes it convenient to obtain a stable reference from 5.0 volt logic supplies, and since the TL431 operates as a shunt regulator, it can be used as either a positive or negative voltage reference.
FEATURES
l Programmable Output Voltage to 36 Volts l Low Dynamic Output Impedance, 0.22 Ω Typical l Sink Current Capability of 1.0 to 100 mA l Equivalent Full-Range Temperature Coefficient of 50 ppm/ oC Typical l Temperature Compensated for operation over Full Rated Operating Temperature Range l Low Output Noise Voltage
PIN ARRANGEMENT TO-92 DIP-8
Pin: 1. Reference 2. Anode 3. Cathode
Pin: 1. Cathode 6. Anode 8. Reference Other Pins: NC
SOP-8
CIRCUIT SCHEMATIC
Pin: 1. 2. 3. 4. Cathode Anode Reference NC 5. 6. 7. 8. NC Anode Anode Reference
SYMBOL
FUNCTIONAL BLOCK DIAGRAM
This SOP-8 is an internally modified SOP-8 Package. Pins 2, 3, 6 and 7 are electrically common to the die attach flag. This internal lead frame modification decreases package thermal resistance and increases power dissipation capability when appropriately mounted on a printed circuit board. This SOP-8 conforms to all external dimensions of the standard SOP-8 package.
ORDERING INFORMATION Device TL431CT TL431CD TL431CS TL431IT TL431ID TL431IS Temperature Range 0 to +70 oC Package TO-92 DIP-8 SOP-8 TO-92 DIP-8 SOP-8
-40 to +85 oC
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TL431 Programmable Precision References
MAXIMUM RATINGS
Rating Cathode to Anode Voltage
(Full operating ambient temperature range applies unless otherwise noted.) Symbol VKA IK Iref TJ TA -40 to +85 0 to +70 T stg
o
Va l u e 37 -100 to +150 -0.05 to +10 150
Unit V mA mA
o o
Cathode Current Range, Continuous Reference Input Current Range, Continuous Operating Junction Temperature Operating Ambient Temperature Range TL431I, TL431AI, TL431BI TL431C, TL431AC, TL431BC Storage Temperature Range Total Power Dissipation @ TA = 25 C Derate above TA = 25oC Ambient Temperature T, S Suffix Packages D Suffix Package Total Power Dissipation @ TC = 25oC Derate above TA = 25oC Case Temperature T, S Suffix Packages D Suffix Package
C C
-65 to +150
o
C
PD 0.70 1.10 PD 1.5 3.0
W
W
THERMAL CHARACTERISTICS
Characteristic Thermal Resistance, Junction to Ambient Thermal Resistance, Junction to Case Symbol Rθ JA Rθ JC T, S Suffix 178 83 D Suffix 114 41 Unit
o o
C/W C/W
RECOMMENDED OPERATING CONDITIONS
Condition / Value Thermal Resistance, Junction to Ambient Thermal Resistance, Junction to Case Symbol VΚA IK Min Vref 1.0 Max 36 100 Unit V mA
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TL431 Programmable Precision References
ELECTRICAL CHARACTERISTICS (Ambient temperature at 25oC unless otherwise noted)
TL431I Typ Max TL431C Typ Max
Characteristic
Reference Input Voltage (Fig. 1) VKA = Vref, IK = 10mA TA = 25oC TA = Tlow to Thigh (Note 1) Reference Input Voltage Deviation Over Temperature Range (Fig. 1, Note 1, 2, 4) VKA = Vref, IK = 10mA Ratio of Change in Reference Input Voltage to Change in Cathode to Anode Voltage IK = 10mA (Fig. 2), ∆VKA = 10V to Vref ∆VKA = 36V to 10V Reference Input Current (Fig. 2) IK = 10mA, R1 = 10k, R2 = TA = 25oC TA = Tlow to Thigh (Note 1) 8 Reference Input Current Deviation Over Temperature Range (Fig. 2, Note 1, 4) IK = 10mA, R1 = 10k, R2 = 8 Minimum Cathode Current for Regulation VKA = Vref (Fig. 1) Off - State Cathode Current (Fig. 3) VKA = 36V, Vref = 0V Dynamic Impedance (Fig. 1, Note 3) VKA = Vref, ∆IK = 1.0mA to 100mA, f < 1.0 kHz
Symbol
Vref
Min
Min
Unit
V
2.44 2.41 ∆Vref ---
2.495 --7.0
2.55 2.58 30
2.44 2.423 ---
2.495 --3.0
2.55 2.567 17 mV
∆Vref ∆VKA ----Iref ----∆Iref --1.8 --0.8 4.0 6.5 2.5 ------1.8 --0.4 4.0 5.2 1.2 -1.4 -1.0 -2.7 -2.0 -----1.4 -1.0 -2.7 -2.0
mV/V
µA
µA
Imin Ioff ZKA
-------
0.5 260 0.22
1.0 1000 0.5
-------
0.5 2.6 0.22
1.0 1000 0.5
mA nA Ω
ELECTRICAL CHARACTERISTICS (Ambient temperature at 25oC unless otherwise noted)
TL431AI Typ Max TL431AC Min Typ Max TL431B Typ Max
Characteristic
Reference Input Voltage (Fig. 1) VKA = Vref, IK = 10mA TA = 25oC TA = Tlow to Thigh (Note 1) Reference Input Voltage Deviation Over Temperature Range (Fig. 1, Note 1, 2, 4) VKA = Vref, IK = 10mA Ratio of Change in Reference Input Voltage to Change in Cathode to Anode Voltage IK = 10mA (Fig. 2), ∆VKA = 10V to Vref ∆VKA = 36V to 10V Reference Input Current (Fig. 2) IK = 10mA, R1 = 10k, R2 = TA = 25oC TA = Tlow to Thigh (Note 1) 8 Reference Input Current Deviation Over Temperature Range (Fig. 2, Note 1, 4) IK = 10mA, R1 = 10k, R2 = Minimum Cathode Current for Regulation VKA = Vref (Fig. 1) Off - State Cathode Current (Fig. 3) VKA = 36V, Vref = 0V Dynamic Impedance (Fig. 1, Note 3) VKA = Vref, ∆IK = 1.0mA to 100mA, f < 1.0 kHz 8
Symbol
Vref
Min
Min
Unit
V
2.47 2.44 ∆Vref ---
2.495 --7.0
2.52 2.55 30
2.47 2.453 ---
2.495 --3.0
2.52 2.537 17
2.483 2.475 ---
2.495 2.495 3.0
2.507 2.515 17 mV
∆Vref ∆VKA ----Iref ----∆Iref --1.8 --0.8 4.0 6.5 2.5 ------1.8 --0.4 4.0 5.2 1.2 ------1.1 --0.4 2.0 4.0 1.2 -1.4 -1.0 -2.7 -2.0 -----1.4 -1.0 -2.7 -2.0 -----1.4 -1.0 -2.7 -2.0
mV/V
µA
µA
Imin Ioff ZKA
-------
0.5 260 0.22
1.0 1000 0.5
-------
0.5 260 0.22
1.0 1000 0.5
-------
0.5 230 0.14
1.0 500 0.3
mA nA Ω
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