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 PIN ARRANGEMENT l Programmable Output Voltage to 36 Volts TO-92 DIP-8 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 Pin: 1. Reference 2. Anode 3. Cathode Full Rated Operating Temperature Range l Low Output Noise Voltage Pin: 1. Cathode 6. Anode 8. Reference Other Pins: NC SOP-8 CIRCUIT SCHEMATIC Pin: 1. 2. 3. 4. SYMBOL Cathode Anode Reference NC 5. 6. 7. 8. NC Anode Anode Reference 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. FUNCTIONAL BLOCK DIAGRAM ORDERING INFORMATION Device TL431CT TL431CD TL431CS TL431IT TL431ID TL431IS 9-1 Temperature Range 0 to +70 oC -40 to +85 oC Package TO-92 DIP-8 SOP-8 TO-92 DIP-8 SOP-8 TL431 Programmable Precision References MAXIMUM RATINGS (Full operating ambient temperature range applies unless otherwise noted.) Rating Symbol Va l u e VKA 37 V Cathode Current Range, Continuous IK -100 to +150 mA mA Cathode to Anode Voltage Unit Reference Input Current Range, Continuous Iref -0.05 to +10 Operating Junction Temperature TJ 150 Operating Ambient Temperature Range TL431I, TL431AI, TL431BI TL431C, TL431AC, TL431BC TA Storage Temperature Range T stg o C o C -40 to +85 0 to +70 o Total Power Dissipation @ TA = 25 C Derate above TA = 25oC Ambient Temperature T, S Suffix Packages D Suffix Package PD Total Power Dissipation @ TC = 25oC Derate above TA = 25oC Case Temperature T, S Suffix Packages D Suffix Package PD o -65 to +150 C W 0.70 1.10 W 1.5 3.0 THERMAL CHARACTERISTICS Characteristic Thermal Resistance, Junction to Ambient Thermal Resistance, Junction to Case Symbol T, S Suffix Rθ JA 178 D Suffix Unit 114 o C/W 83 41 o C/W Symbol Min Max VΚA Vref 36 V IK 1.0 100 mA Rθ JC RECOMMENDED OPERATING CONDITIONS Condition / Value Thermal Resistance, Junction to Ambient Thermal Resistance, Junction to Case 9-2 Unit TL431 Programmable Precision References ELECTRICAL CHARACTERISTICS (Ambient temperature at 25oC unless otherwise noted) Characteristic Symbol Reference Input Voltage (Fig. 1) VKA = Vref, IK = 10mA TA = 25oC TA = Tlow to Thigh (Note 1) Min TL431I Typ Max Min TL431C Typ Max Unit Vref V Reference Input Voltage Deviation Over Temperature Range (Fig. 1, Note 1, 2, 4) VKA = Vref, IK = 10mA ∆Vref 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 ∆Vref ∆VKA 2.44 2.41 2.495 --- 2.55 2.58 2.44 2.423 2.495 --- 2.55 2.567 --- 7.0 30 --- 3.0 17 mV/V ----- -1.4 -1.0 -2.7 -2.0 ----- -1.4 -1.0 -2.7 -2.0 µA Iref 8 Reference Input Current (Fig. 2) IK = 10mA, R1 = 10k, R2 = TA = 25oC TA = Tlow to Thigh (Note 1) mV ----- 1.8 --- 4.0 6.5 ----- 1.8 --- 4.0 5.2 ∆Iref --- 0.8 2.5 --- 0.4 1.2 µA Minimum Cathode Current for Regulation VKA = Vref (Fig. 1) Imin --- 0.5 1.0 --- 0.5 1.0 mA Off - State Cathode Current (Fig. 3) VKA = 36V, Vref = 0V Ioff --- 260 1000 --- 2.6 1000 nA Dynamic Impedance (Fig. 1, Note 3) VKA = Vref, ∆IK = 1.0mA to 100mA, f < 1.0 kHz ZKA --- 0.22 0.5 --- 0.22 0.5 Ω 8 Reference Input Current Deviation Over Temperature Range (Fig. 2, Note 1, 4) IK = 10mA, R1 = 10k, R2 = ELECTRICAL CHARACTERISTICS (Ambient temperature at 25oC unless otherwise noted) Characteristic Symbol Reference Input Voltage (Fig. 1) VKA = Vref, IK = 10mA TA = 25oC TA = Tlow to Thigh (Note 1) TL431AI Typ Max TL431AC Min Typ Max Min TL431B Typ Max Vref Reference Input Voltage Deviation Over Temperature Range (Fig. 1, Note 1, 2, 4) VKA = Vref, IK = 10mA ∆Vref 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 ∆Vref ∆VKA Unit V 2.47 2.44 2.495 --- 2.52 2.55 2.47 2.453 2.495 --- 2.52 2.537 2.483 2.475 2.495 2.495 2.507 2.515 --- 7.0 30 --- 3.0 17 --- 3.0 17 mV mV/V ----- -1.4 -1.0 -2.7 -2.0 ----- -1.4 -1.0 -2.7 -2.0 ----- -1.4 -1.0 -2.7 -2.0 µA Iref 8 Reference Input Current (Fig. 2) IK = 10mA, R1 = 10k, R2 = TA = 25oC TA = Tlow to Thigh (Note 1) Min ----- 1.8 --- 4.0 6.5 ----- 1.8 --- 4.0 5.2 ----- 1.1 --- 2.0 4.0 ∆Iref --- 0.8 2.5 --- 0.4 1.2 --- 0.4 1.2 µA Minimum Cathode Current for Regulation VKA = Vref (Fig. 1) Imin --- 0.5 1.0 --- 0.5 1.0 --- 0.5 1.0 mA Off - State Cathode Current (Fig. 3) VKA = 36V, Vref = 0V Ioff --- 260 1000 --- 260 1000 --- 230 500 nA Dynamic Impedance (Fig. 1, Note 3) VKA = Vref, ∆IK = 1.0mA to 100mA, f < 1.0 kHz ZKA --- 0.22 0.5 --- 0.22 0.5 --- 0.14 0.3 Ω 8 Reference Input Current Deviation Over Temperature Range (Fig. 2, Note 1, 4) IK = 10mA, R1 = 10k, R2 = 9-3 9-4