Order this document by TL431/D The TL431, A, B 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 V with two external resistors. These devices exhibit a wide operating current range of 1.0 mA to 100 mA with a typical dynamic impedance of 0.22 . 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 V reference makes it convenient to obtain a stable reference from 5.0 V logic supplies, and since the TL431, A, B operates as a shunt regulator, it can be used as either a positive or negative voltage reference. * * * * * * * Programmable Output Voltage to 36 V Voltage Reference Tolerance: 0.4%, Typ @ 25C (TL431B) Low Dynamic Output Impedance, 0.22 Typical PROGRAMMABLE PRECISION REFERENCES SEMICONDUCTOR TECHNICAL DATA LP SUFFIX PLASTIC PACKAGE CASE 29 (TO-92) 1 Sink Current Capability of 1.0 mA to 100 mA 2 Pin 1. Reference 2. Anode 3. Cathode 3 Equivalent Full-Range Temperature Coefficient of 50 ppm/C Typical Temperature Compensated for Operation over Full Rated Operating Temperature Range Low Output Noise Voltage P SUFFIX PLASTIC PACKAGE CASE 626 8 1 DM SUFFIX PLASTIC PACKAGE CASE 846A (Micro-8) 8 1 8 Reference Cathode 1 N/C 2 7 N/C N/C 3 6 Anode N/C 4 5 N/C (Top View) D SUFFIX PLASTIC PACKAGE CASE 751 (SOP-8) ORDERING INFORMATION Device Operating Temperature Range TL431CLP, ACLP, BCLP TO-92 TL431CP, ACP, BCP TL431CDM, ACDM, BCDM Package Plastic TA = 0 to +70C 70C 8 1 Cathode 1 8 2 7 3 6 N/C 4 5 Anode Reference Anode N/C Micro-8 (Top View) TL431CD, ACD, BCD SOP-8 TL431ILP, AILP, BILP TO-92 TL431IP, AIP, BIP TL431IDM, AIDM, BIDM Plastic TA = -40 40 to +85C 85C TL431ID, AID, BID Micro-8 SOP-8 is an internally modified SO-8 package. Pins 2, 3, 6 and 7 are electrically common to the die attach flag. This internal lead frame modification decreases power dissipation capability when appropriately mounted on a printed circuit board. SOP-8 conforms to all external dimensions of the standard SO-8 package. SOP-8 Motorola, Inc. 1998 MOTOROLA ANALOG IC DEVICE DATA Rev 6 1 TL431, A, B Series Symbol Representative Schematic Diagram Component values are nominal Cathode (K) Cathode (K) Reference (R) 800 800 Reference (R) Anode (A) 20 pF Representative Block Diagram Reference (R) 4.0 k 20 pF Cathode (K) + 150 3.28 k 2.4 k 10 k 7.2 k - 1.0 k 2.5 Vref 800 Anode (A) Anode (A) This device contains 12 active transistors. MAXIMUM RATINGS (Full operating ambient temperature range applies, unless otherwise noted.) Rating Symbol Value Unit VKA 37 V Cathode Current Range, Continuous IK -100 to +150 mA Reference Input Current Range, Continuous Iref -0.05 to +10 mA Operating Junction Temperature TJ 150 C Operating Ambient Temperature Range TL431I, TL431AI, TL431BI TL431C, TL431AC, TL431BC TA Cathode to Anode Voltage Storage Temperature Range Tstg Total Power Dissipation @ TA = 25C Derate above 25C Ambient Temperature D, LP Suffix Plastic Package P Suffix Plastic Package DM Suffix Plastic Package PD Total Power Dissipation @ TC = 25C Derate above 25C Case Temperature D, LP Suffix Plastic Package P Suffix Plastic Package PD NOTE: C -40 to +85 0 to +70 -65 to +150 C W 0.70 1.10 0.52 W 1.5 3.0 ESD data available upon request. RECOMMENDED OPERATING CONDITIONS Condition Cathode to Anode Voltage Symbol Min Max Unit VKA Vref 36 V IK 1.0 100 mA Cathode Current THERMAL CHARACTERISTICS Symbol D, LP Suffix Package P Suffix Package DM Suffix Package Unit Thermal Resistance, Junction-to-Ambient RJA 178 114 240 C/W Thermal Resistance, Junction-to-Case RJC 83 41 - C/W Characteristic 2 MOTOROLA ANALOG IC DEVICE DATA TL431, A, B Series ELECTRICAL CHARACTERISTICS (TA = 25C, unless otherwise noted.) TL431I Ch Characteristic i i S b l Symbol Reference Input Voltage (Figure 1) VKA = Vref, IK = 10 mA TA = 25C TA = Tlow to Thigh (Note 1) Min Typ TL431C Max Min Typ Max Vref V Reference Input Voltage Deviation Over Temperature Range (Figure 1, Notes 1, 2) VKA= Vref, IK = 10 mA Vref Ratio of Change in Reference Input Voltage to Change in Cathode to Anode Voltage IK = 10 mA (Figure 2), VKA = 10 V to Vref VKA = 36 V to 10 V DVref DVKA 2.44 2.41 2.495 - 2.55 2.58 2.44 2.423 2.495 - 2.55 2.567 - 7.0 - - 3.0 - mV mV/V - - Reference Input Current (Figure 2) IK = 10 mA, R1 = 10 k, R2 = TA = 25C TA = Tlow to Thigh (Note 1) Unit -1.4 -1.0 -2.7 -2.0 - - -1.4 -1.0 -2.7 -2.0 A Iref - - 1.8 - 4.0 6.5 - - 1.8 - 4.0 5.2 Reference Input Current Deviation Over Temperature Range (Figure 2, Note 1, 4) IK = 10 mA, R1 = 10 k, R2 = Iref - 0.8 2.5 - 0.4 1.2 A Minimum Cathode Current For Regulation VKA = Vref (Figure 1) Imin - 0.5 1.0 - 0.5 1.0 mA Off-State Cathode Current (Figure 3) VKA = 36 V, Vref = 0 V Ioff - 260 1000 - 2.6 1000 nA |ZKA| - 0.22 0.5 - 0.22 0.5 Dynamic Impedance (Figure 1, Note 3) VKA = Vref, IK = 1.0 mA to 100 mA f 1.0 kHz NOTES: 1. Tlow = -40C for TL431AIP TL431AILP, TL431IP, TL431ILP, TL431BID, TL431BIP, TL431BILP, TL431AIDM, TL431IDM, TL431BIDM = 0C for TL431ACP, TL431ACLP, TL431CP, TL431CLP, TL431CD, TL431ACD, TL431BCD, TL431BCP, TL431BCLP, TL431CDM, TL431ACDM, TL431BCDM Thigh = +85C for TL431AIP, TL431AILP, TL431IP, TL431ILP, TL431BID, TL431BIP, TL431BILP, TL431IDM, TL431AIDM, TL431BIDM = +70C for TL431ACP, TL431ACLP, TL431CP, TL431ACD, TL431BCD, TL431BCP, TL431BCLP, TL431CDM, TL431ACDM, TL431BCDM 2. The deviation parameter Vref is defined as the difference between the maximum and minimum values obtained over the full operating ambient temperature range that applies. Vref max Vref = Vref max -Vref min TA = T2 - T1 Vref min T1 T2 Ambient Temperature The average temperature coefficient of the reference input voltage, Vref is defined as: D Vref V @ 25_C X 10 6 D x 10 6 ref D TA (V @ 25_C) A ref Vref can be positive or negative depending on whether Vref Min or Vref Max occurs at the lower ambient temperature. (Refer to Figure 6.) ppm V ref _C + 8.0 mV and slope is positive, @ 25_C + 2.495 V, DT + 70_C ref A Example : DV V + ref ref 3. The dynamic impedance ZKA is defined as |Z KA| + DDVIKA +DT a V ref V x 106 + 45.8 ppm_C + 0.008 70 (2.495) K When the device is programmed with two external resistors, R1 and R2, (refer to Figure 2) the total dynamic impedance of the circuit is defined as: |Z MOTOROLA ANALOG IC DEVICE DATA | [ |ZKA| KA 1 ) R1 R2 3 TL431, A, B Series ELECTRICAL CHARACTERISTICS (TA = 25C, unless otherwise noted.) TL431AI Ch Characteristic i i S b l Symbol Reference Input Voltage (Figure 1) VKA = Vref, IK = 10 mA TA = 25C TA = Tlow to Thigh Min Typ TL431AC Max Min Typ TL431B Max Min Typ Max Unit Vref 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 - - 3.0 - - 3.0 - Vref Reference Input Voltage Deviation Over Temperature Range (Figure 1, Notes 1, 2) VKA= Vref, IK = 10 mA DVref DVKA Ratio of Change in Reference Input Voltage to Change in Cathode to Anode Voltage IK = 10 mA (Figure 2), VKA = 10 V to Vref VKA = 36 V to 10 V mV mV/V - - Reference Input Current (Figure 2) IK = 10 mA, R1 = 10 k, R2 = TA = 25C TA = Tlow to Thigh (Note 1) Iref Reference Input Current Deviation Over Temperature Range (Figure 2, Note 1) IK = 10 mA, R1 = 10 k, R2 = -1.4 -1.0 -2.7 -2.0 - - -1.4 -1.0 -2.7 -2.0 - - -1.4 -1.0 -2.7 -2.0 A - - 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 A Minimum Cathode Current For Regulation VKA = Vref (Figure 1) Imin - 0.5 1.0 - 0.5 1.0 - 0.5 1.0 mA Off-State Cathode Current (Figure 3) VKA = 36 V, Vref = 0 V Ioff - 260 1000 - 260 1000 - 230 500 nA |ZKA| - 0.22 0.5 - 0.22 0.5 - 0.14 0.3 Dynamic Impedance (Figure 1, Note 3) VKA = Vref, IK = 1.0 mA to 100 mA f 1.0 kHz NOTES: 1. Tlow = -40C for TL431AIP TL431AILP, TL431IP, TL431ILP, TL431BID, TL431BIP, TL431BILP, TL431AIDM, TL431IDM, TL431BIDM = 0C for TL431ACP, TL431ACLP, TL431CP, TL431CLP, TL431CD, TL431ACD, TL431BCD, TL431BCP, TL431BCLP, TL431CDM, TL431ACDM, TL431BCDM Thigh = +85C for TL431AIP, TL431AILP, TL431IP, TL431ILP, TL431BID, TL431BIP, TL431BILP, TL431IDM, TL431AIDM, TL431BIDM = +70C for TL431ACP, TL431ACLP, TL431CP, TL431ACD, TL431BCD, TL431BCP, TL431BCLP, TL431CDM, TL431ACDM, TL431BCDM 2. The deviation parameter Vref is defined as the difference between the maximum and minimum values obtained over the full operating ambient temperature range that applies. Vref max Vref = Vref max -Vref min TA = T2 - T1 Vref min T1 T2 Ambient Temperature The average temperature coefficient of the reference input voltage, Vref is defined as: D Vref V @ 25_C X 10 6 D V x 10 6 ref (V @ 25_C) A A ref Vref can be positive or negative depending on whether Vref Min or Vref Max occurs at the lower ambient temperature. (Refer to Figure 6.) ppm V ref _C D T + 8.0 mV and slope is positive, @ 25_C + 2.495 V, DT + 70_C ref A Example : DV V + ref ref 3. The dynamic impedance ZKA is defined as |Z KA| + DDVIKA +DT a V ref x 106 + 45.8 ppm_C + 0.008 70 (2.495) K When the device is programmed with two external resistors, R1 and R2, (refer to Figure 2) the total dynamic impedance of the circuit is defined as: |Z 4 | [ |ZKA| KA 1 ) R1 R2 MOTOROLA ANALOG IC DEVICE DATA TL431, A, B Series Figure 1. Test Circuit for VKA = Vref Input Figure 2. Test Circuit for VKA > Vref VKA Input VKA IK Iref R1 Vref Figure 3. Test Circuit for Ioff R2 Input V KA VKA Ioff IK + Vref 1 ) R1 ) Iref S R1 R2 Vref Figure 4. Cathode Current versus Cathode Voltage Figure 5. Cathode Current versus Cathode Voltage 800 VKA = Vref TA = 25C 100 Input IK , CATHODE CURRENT ( A) IK , CATHODE CURRENT (mA) 150 VKA IK 50 0 -50 -100 -2.0 -1.0 0 1.0 2.0 3.0 600 Input VKA = Vref TA = 25C 400 200 0 -200 -1.0 0 VKA, CATHODE VOLTAGE (V) VKA IKVKA = Vref IK = 10 mA Input 2560 Vref Vref Max = 2550 mV 2540 2520 Vref Typ = 2495 mV 2500 2480 2460 2440 Vref Min = 2440 mV 2420 2400 -55 -25 0 25 50 75 TA, AMBIENT TEMPERATURE (C) MOTOROLA ANALOG IC DEVICE DATA 2.0 3.0 Figure 7. Reference Input Current versus Ambient Temperature 100 125 Iref , REFERENCE INPUT CURRENT ( A) Vref , REFERENCE INPUT VOLTAGE (mV) 2580 1.0 VKA, CATHODE VOLTAGE (V) Figure 6. Reference Input Voltage versus Ambient Temperature 2600 IMin VKA IK 3.0 2.5 2.0 1.5 IK = 10 mA 1.0 Input 10k Iref VKA IK 0.5 0 -55 -25 0 25 50 75 125 100 TA, AMBIENT TEMPERATURE (C) 5 TL431, A, B Series Figure 9. Off-State Cathode Current versus Ambient Temperature 0 IK = 10 mA TA = 25C -8.0 -16 Input VKA IK R1 -24 -32 R2 Vref 0 10 20 30 1.0 k Ioff , OFF-STATE CATHODE CURRENT (nA) Vref , REFERENCE INPUT VOLTAGE (mV) Figure 8. Change in Reference Input Voltage versus Cathode Voltage 100 10 1.0 Input 0.1 0.01 -55 40 -25 0 VKA, CATHODE VOLTAGE (V) 50 10 - + Gnd 1.0 0.1 1.0 k 10 k 100 k 1.0 M 10 M 0.280 0.260 125 100 125 0.240 0.220 0.200 -55 -25 0 25 50 75 TA, AMBIENT TEMPERATURE (_C) Figure 12. Open-Loop Voltage Gain versus Frequency Figure 13. Spectral Noise Density 80 60 50 9.0 F 40 IK 15 k Output 230 NOISE VOLTAGE (nV/ Hz) A VOL, OPEN LOOP VOLTAGE GAIN (dB) 100 VKA = Vref IK = 1.0 mA to 100 mA f 1.0 kHz Output 1.0 k IK 50 - + Gnd 0.300 f, FREQUENCY (MHz) 8.25 k Gnd 30 20 10 75 0.320 TA = 25_C IK = 1.0 mA to 100 mA Output IK 50 Figure 11. Dynamic Impedance versus Ambient Temperature |ZKA|, DYNAMIC IMPEDANCE ( ) |ZKA|, DYNAMIC IMPEDANCE ( ) 1.0 k 25 TA, AMBIENT TEMPERATURE (5C) Figure 10. Dynamic Impedance versus Frequency 100 VKA = 36 V Vref = 0 V VKA Ioff IK = 10 mA TA = 25_C 60 40 Input VKA = Vref IK = 10 mA TA = 25C 20 Output IK 0 -10 1.0 k 10 k 100 k f, FREQUENCY (MHz) 6 1.0 M 10 M 0 10 100 1.0 k 10 k 100 k f, FREQUENCY (Hz) MOTOROLA ANALOG IC DEVICE DATA TL431, A, B Series Figure 14. Pulse Response TA = 25_C Input Monitor Output 2.0 Pulse Generator f = 100 kHz 1.0 220 Output 50 Gnd 0 5.0 0 4.0 120 100 A) VKA = Vref B) VKA = 5.0 V @ IK = 10 mA C) VKA = 10 V @ IK = 10 mA D) VKA = 15 V @ IK = 10 mA D) TA = 25C Stable A A B B 80 Stable C 60 D 40 20 Input 0 IK , CATHODE CURRENT (mA) VOLTAGE SWING (V) 3.0 Figure 15. Stability Boundary Conditions 140 12 8.0 16 20 0 100 pF 1000 pF 0.01 F 0.1 F 1.0 F 10 F CL, LOAD CAPACITANCE t, TIME (s) Figure 16. Test Circuit For Curve A of Stability Boundary Conditions Figure 17. Test Circuit For Curves B, C, And D of Stability Boundary Conditions 150 150 IK IK V+ 10 k V+ CL CL TYPICAL APPLICATIONS Figure 18. Shunt Regulator V+ Figure 19. High Current Shunt Regulator Vout V+ Vout R1 R1 R2 V out + 1 ) R1 R2 R2 V ref MOTOROLA ANALOG IC DEVICE DATA V out + 1 ) R1 R2 V ref 7 TL431, A, B Series Figure 20. Output Control for a Three-Terminal Fixed Regulator Figure 21. Series Pass Regulator V+ MC7805 Out In Common V+ Vout R1 Vout R1 R2 V out Figure 22. Constant Current Source RCL V+ + 1 ) R1 V ref R2 V out min + V ) V ref be + 1 ) R1 V ref R2 V out min + V ) 5.0V ref V out R2 Figure 23. Constant Current Sink V+ Iout Isink I I out Sink CL RS V+ Vout Figure 25. SRC Crowbar V+ Vout R1 8 out(trip) S + RVref Figure 24. TRIAC Crowbar V + VRref + 1) R1 R2 R1 V ref R2 V out(trip) + 1 ) R1 R2 R2 V ref MOTOROLA ANALOG IC DEVICE DATA TL431, A, B Series Figure 26. Voltage Monitor V+ Figure 27. Single-Supply Comparator with Temperature-Compensated Threshold Vout l R1 V+ R3 Vout Vin R2 R4 Vth = Vref L.E.D. indicator is `on' when V+ is between the upper and lower limits. + 1 ) R1 R2 Upper Limit + 1 ) R3 R4 Lower Limit V V 50 k 1% 10 k V 1.0 k V 500 k 1% 100 k V 25 V - LM11 + Range RX Rx + Vout D 38 V Tl = 330 to 8.0 W V -5.0 V Range MOTOROLA ANALOG IC DEVICE DATA 330 TI 10 k Calibrate 1.0 M V 2.0 V Figure 29. Simple 400 mW Phono Amplifier 2.0 mA 5.0 M 1% > Vref ref 25 V 5.0 k 1% Vout V+ ref Figure 28. Linear Ohmmeter 1N5305 Vin < Vref 8.0 + 470 F 360 k 1.0 F * Vout * Thermalloy * THM 6024 * Heatsink on * LP Package 56 k 10 k 0.05 F Tone 25 k Volume 47 k 9 TL431, A, B Series Figure 30. High Efficiency Step-Down Switching Converter 150 mH @ 2.0 A Vin = 10 V to 20 V TIP115 Vout = 5.0 V Iout = 1.0 A 1.0 k 4.7 k + 4.7 k MPSA20 1N5823 0.01F 100 k 2200 F 470 F 4.7 k + 0.1 F 2.2 k Test 10 51 k 10 Conditions Results Line Regulation Vin = 10 V to 20 V, Io = 1.0 A 53 mV (1.1%) Load Regulation Vin = 15 V, Io = 0 A to 1.0 A 25 mV (0.5%) Output Ripple Vin = 10 V, Io = 1.0 A 50 mVpp P.A.R.D. Output Ripple Vin = 20 V, Io = 1.0 A 100 mVpp P.A.R.D. Efficiency Vin = 15 V, Io = 1.0 A 82% MOTOROLA ANALOG IC DEVICE DATA TL431, A, B Series APPLICATIONS INFORMATION The TL431 is a programmable precision reference which is used in a variety of ways. It serves as a reference voltage in circuits where a non-standard reference voltage is needed. Other uses include feedback control for driving an optocoupler in power supplies, voltage monitor, constant current source, constant current sink and series pass regulator. In each of these applications, it is critical to maintain stability of the device at various operating currents and load capacitances. In some cases the circuit designer can estimate the stabilization capacitance from the stability boundary conditions curve provided in Figure 15. However, these typical curves only provide stability information at specific cathode voltages and at a specific load condition. Additional information is needed to determine the capacitance needed to optimize phase margin or allow for process variation. A simplified model of the TL431 is shown in Figure 31. When tested for stability boundaries, the load resistance is 150 W. The model reference input consists of an input transistor and a dc emitter resistance connected to the device anode. A dependent current source, Gm, develops a current whose amplidute is determined by the difference between the 1.78 V internal reference voltage source and the input transistor emitter voltage. A portion of Gm flows through compensation capacitance, CP2. The voltage across CP2 drives the output dependent current source, Go, which is connected across the device cathode and anode. Model component values are: Vref = 1.78 V Gm = 0.3 + 2.7 exp (-IC/26 mA) Go = 1.25 (Vcp2) mhos. Resistor and capacitor typical values are shown on the model. Process tolerances are 20% for resistors, 10% for capacitors, and 40% for transconductances. An examination of the device model reveals the location of circuit poles and zeroes: 1 1 P1 7.96 kHz 2p R C 2 p * 1.0 M * 20 pF GM P1 + MOTOROLA ANALOG IC DEVICE DATA + 2p R 1 C + 2p * 10 M1* 0.265 pF + 60 kHz P2 P2 Z1 + 2p R 1 C + 2p * 15.91k * 20 pF + 500 kHz Z1 P1 In addition, there is an external circuit pole defined by the load: 1 P L 2p R C L L Also, the transfer dc voltage gain of the TL431 is: + G + + GMRGMGoRL Example 1: I C + 10 mA, RL+ 230 W, CL+ 0. Define the transfer gain. The DC gain is: + GMRGMGoRL + (2.138)(1.0 M)(1.25 m)(230) + 615 + 56 dB 8.25 k Loop gain + G + 218 + 47 dB 8.25 k ) 15 k G The resulting transfer function Bode plot is shown in Figure 32. The asymptotic plot may be expressed as the following equation: 1 jf 500 kHz Av 615 1 jf 1 jf 8.0 kHz 60 kHz + where IC is the device cathode current and Gm is in mhos + P2 ) ) ) The Bode plot shows a unity gain crossover frequency of approximately 600 kHz. The phase margin, calculated from the equation, would be 55.9 degrees. This model matches the Open-Loop Bode Plot of Figure 12. The total loop would have a unity gain frequency of about 300 kHz with a phase margin of about 44 degrees. 11 TL431, A, B Series Figure 31. Simplified TL431 Device Model VCC RL CL Input 3 15 k Cathode 9.0 mF Ref RP2 10 M Vref 1.78 V + - 1 500 k 8.25 k RGM 1.0 M Anode Figure 32. Example 1 Circuit Open Loop Gain Plot RZ1 15.9 k CP2 0.265 pF 2 Note that the transfer function now has an extra pole formed by the load capacitance and load resistance. Note that the crossover frequency in this case is about 250 kHz, having a phase margin of about -46 degrees. Therefore, instability of this circuit is likely. TL431 OPEN-LOOP VOLTAGE GAIN VERSUS FREQUENCY 60 50 Figure 33. Example 2 Circuit Open Loop Gain Plot 40 30 TL431 OPEN-LOOP BODE PLOT WITH LOAD CAP 80 20 10 0 -10 -20 101 103 102 104 105 106 107 f, FREQUENCY (Hz) Example 2. IC = 7.5 mA, RL = 2.2 kW, CL = 0.01 mF. Cathode tied to reference input pin. An examination of the data sheet stability boundary curve (Figure 15) shows that this value of load capacitance and cathode current is on the boundary. Define the transfer gain. The DC gain is: + GMRGMGoRL + (2.323)(1.0 M)(1.25 m)(2200) + 6389 + 76 dB G The resulting open loop Bode plot is shown in Figure 33. The asymptotic plot may be expressed as the following equation: 1 jf 500 kHz Av 615 1 jf 1 jf 1 jf 8.0 kHz 60 kHz 7.2 kHz + 12 ) ) ) ) Av, OPEN-LOOP GAIN (dB) Av, OPEN-LOOP VOLTAGE GAIN (dB) CP1 20 pF GM Rref 16 Go 1.0 mmho 60 40 20 0 -20 101 102 103 104 105 106 f, FREQUENCY (Hz) With three poles, this system is unstable. The only hope for stabilizing this circuit is to add a zero. However, that can only be done by adding a series resistance to the output capacitance, which will reduce its effectiveness as a noise filter. Therefore, practically, in reference voltage applications, the best solution appears to be to use a smaller value of capacitance in low noise applications or a very large value to provide noise filtering and a dominant pole rolloff of the system. MOTOROLA ANALOG IC DEVICE DATA TL431, A, B Series OUTLINE DIMENSIONS A LP SUFFIX PLASTIC PACKAGE CASE 29-04 (TO-92) ISSUE AE B R P L F SEATING PLANE K DIM A B C D F G H J K L N P R V D X X G J H V C SECTION X-X 1 NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. 3. CONTOUR OF PACKAGE BEYOND DIMENSION R IS UNCONTROLLED. 4. DIMENSION F APPLIES BETWEEN P AND L. DIMENSION D AND J APPLY BETWEEN L AND K MINIMUM. LEAD DIMENSION IS UNCONTROLLED IN P AND BEYOND DIMENSION K MINIMUM. N N INCHES MIN MAX 0.175 0.205 0.170 0.210 0.125 0.165 0.016 0.022 0.016 0.019 0.045 0.055 0.095 0.105 0.015 0.020 0.500 --- 0.250 --- 0.080 0.105 --- 0.100 0.115 --- 0.135 --- MILLIMETERS MIN MAX 4.45 5.20 4.32 5.33 3.18 4.19 0.41 0.55 0.41 0.48 1.15 1.39 2.42 2.66 0.39 0.50 12.70 --- 6.35 --- 2.04 2.66 --- 2.54 2.93 --- 3.43 --- P SUFFIX PLASTIC PACKAGE CASE 626-05 ISSUE K 8 5 NOTES: 1. DIMENSION L TO CENTER OF LEAD WHEN FORMED PARALLEL. 2. PACKAGE CONTOUR OPTIONAL (ROUND OR SQUARE CORNERS). 3. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. -B- 1 4 F -A- NOTE 2 L C J -T- N SEATING PLANE D H M K DIM A B C D F G H J K L M N MILLIMETERS MIN MAX 9.40 10.16 6.10 6.60 3.94 4.45 0.38 0.51 1.02 1.78 2.54 BSC 0.76 1.27 0.20 0.30 2.92 3.43 7.62 BSC --- 10_ 0.76 1.01 INCHES MIN MAX 0.370 0.400 0.240 0.260 0.155 0.175 0.015 0.020 0.040 0.070 0.100 BSC 0.030 0.050 0.008 0.012 0.115 0.135 0.300 BSC --- 10_ 0.030 0.040 G 0.13 (0.005) MOTOROLA ANALOG IC DEVICE DATA M T A M B M 13 TL431, A, B Series OUTLINE DIMENSIONS DM SUFFIX PLASTIC PACKAGE CASE 846A-02 (Micro-8) ISSUE D -A- -B- K PIN 1 ID G D 8 PL 0.08 (0.003) -T- NOTES: 6. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 7. CONTROLLING DIMENSION: MILLIMETER. 8. DIMENSION A DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.15 (0.006) PER SIDE. 9. DIMENSION B DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSION. INTERLEAD FLASH OR PROTRUSION SHALL NOT EXCEED 0.25 (0.010) PER SIDE. M T B S A DIM A B C D G H J K L S SEATING PLANE C 0.038 (0.0015) INCHES MIN MAX 0.114 0.122 0.114 0.122 --- 0.043 0.010 0.016 0.026 BSC 0.002 0.006 0.005 0.009 0.187 0.199 0.016 0.028 L J H MILLIMETERS MIN MAX 2.90 3.10 2.90 3.10 --- 1.10 0.25 0.40 0.65 BSC 0.05 0.15 0.13 0.23 4.75 5.05 0.40 0.70 D SUFFIX PLASTIC PACKAGE CASE 751-06 (SOP-8) ISSUE T D A 8 NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M, 1994. 2. DIMENSIONS ARE IN MILLIMETER. 3. DIMENSION D AND E DO NOT INCLUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION 0.15 PER SIDE. 5. DIMENSION B DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.127 TOTAL IN EXCESS OF THE B DIMENSION AT MAXIMUM MATERIAL CONDITION. C 5 0.25 H E M B M 1 4 h B e X 45 _ q A C SEATING PLANE L 0.10 A1 B 0.25 14 M C B S A S DIM A A1 B C D E e H h L q MILLIMETERS MIN MAX 1.35 1.75 0.10 0.25 0.35 0.49 0.19 0.25 4.80 5.00 3.80 4.00 1.27 BSC 5.80 6.20 0.25 0.50 0.40 1.25 0_ 7_ MOTOROLA ANALOG IC DEVICE DATA TL431, A, B Series Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. "Typical" parameters which may be provided in Motorola data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including "Typicals" must be validated for each customer application by customer's technical experts. Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer. MOTOROLA ANALOG IC DEVICE DATA 15 TL431, A, B Series Mfax is a trademark of Motorola, Inc. How to reach us: USA / EUROPE / Locations Not Listed: Motorola Literature Distribution; P.O. Box 5405, Denver, Colorado 80217. 1-303-675-2140 or 1-800-441-2447 JAPAN: Nippon Motorola Ltd.: SPD, Strategic Planning Office, 141, 4-32-1 Nishi-Gotanda, Shagawa-ku, Tokyo, Japan. 03-5487-8488 Customer Focus Center: 1-800-521-6274 Mfax: RMFAX0@email.sps.mot.com - TOUCHTONE 1-602-244-6609 ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park, Motorola Fax Back System - US & Canada ONLY 1-800-774-1848 51 Ting Kok Road, Tai Po, N.T., Hong Kong. 852-26629298 - http://sps.motorola.com/mfax/ HOME PAGE: http://motorola.com/sps/ 16 TL431/D MOTOROLA ANALOG IC DEVICE DATA