TL431AID

Order this document by TL431/D TL431, A, B Programmable Precision References 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 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 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. Series PROGRAMMABLE PRECISION REFERENCES SEMICONDUCTOR TECHNICAL DATA • • • • • • • Programmable Output Voltage to 36 V Voltage Reference Tolerance: ±0.4%, Typ @ 25°C (TL431B) Low Dynamic Output Impedance, 0.22 Ω Typical Sink Current Capability of 1.0 mA to 100 mA Equivalent Full–Range Temperature Coefficient of 50 ppm/°C Typical Temperature Compensated for Operation over Full Rated Operating Temperature Range Low Output Noise Voltage LP SUFFIX PLASTIC PACKAGE CASE 29 (TO–92) 1 2 3 Pin 1. Reference 2. Anode 3. Cathode 8 1 P SUFFIX PLASTIC PACKAGE CASE 626 8 1 DM SUFFIX PLASTIC PACKAGE CASE 846A (Micro–8) Cathode 1 N/C 2 N/C 3 N/C 4 (Top View) 8 Reference 7 N/C 6 Anode 5 N/C ORDERING INFORMATION Device TL431CLP, ACLP, BCLP TL431CP, ACP, BCP TL431CDM, ACDM, BCDM TL431CD, ACD, BCD TL431ILP, AILP, BILP TL431IP, AIP, BIP TL431IDM, AIDM, BIDM TL431ID, AID, BID TA = –40° to +85°C to +85 TA = 0° to +70°C to +70 Operating Temperature Range Package TO–92 Plastic Micro–8 D SUFFIX PLASTIC PACKAGE CASE 751 (SOP–8) Cathode 1 Anode 2 3 N/C 4 (Top View) 8 1 8 7 6 5 Reference Anode N/C SOP–8 TO–92 Plastic Micro–8 SOP–8 © Motorola, Inc. 1998 Rev 6 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. MOTOROLA ANALOG IC DEVICE DATA 1 TL431, A, B Series Symbol Cathode (K) Reference (R) 800 Anode (A) Reference (R) 800 20 pF Representative Schematic Diagram Component values are nominal Cathode (K) Representative Block Diagram Reference (R) Cathode (K) 2.4 k 3.28 k 20 pF 7.2 k 150 4.0 k 10 k + – 2.5 Vref 1.0 k 800 Anode (A) Anode (A) This device contains 12 active transistors. MAXIMUM RATINGS (Full operating ambient temperature range applies, unless otherwise noted.) Rating Cathode to Anode Voltage 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 25°C Ambient Temperature D, LP Suffix Plastic Package P Suffix Plastic Package DM Suffix Plastic Package Total Power Dissipation @ TC = 25°C Derate above 25°C Case Temperature D, LP Suffix Plastic Package P Suffix Plastic Package NOTE: ESD data available upon request. Symbol VKA IK Iref TJ TA Value 37 –100 to +150 –0.05 to +10 150 –40 to +85 0 to +70 Unit V mA mA °C °C Tstg PD –65 to +150 °C W 0.70 1.10 0.52 PD 1.5 3.0 W RECOMMENDED OPERATING CONDITIONS Condition Cathode to Anode Voltage Cathode Current Symbol VKA IK Min Vref 1.0 Max 36 100 Unit V mA THERMAL CHARACTERISTICS Characteristic Thermal Resistance, Junction–to–Ambient Thermal Resistance, Junction–to–Case Symbol RθJA RθJC D, LP Suffix Package 178 83 P Suffix Package 114 41 DM Suffix Package 240 – Unit °C/W °C/W 2 MOTOROLA ANALOG IC DEVICE DATA TL431, A, B Series ELECTRICAL CHARACTERISTICS (TA = 25°C, unless otherwise noted.) TL431I Characteristic Ch ii Reference Input Voltage (Figure 1) VKA = Vref, IK = 10 mA TA = 25°C TA = Tlow to Thigh (Note 1) Reference Input Voltage Deviation Over Temperature Range (Figure 1, Notes 1, 2) VKA= Vref, IK = 10 mA 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 Reference Input Current (Figure 2) IK = 10 mA, R1 = 10 k, R2 = ∞ TA = 25°C TA = Tlow to Thigh (Note 1) Reference Input Current Deviation Over Temperature Range (Figure 2, Note 1, 4) IK = 10 mA, R1 = 10 k, R2 = ∞ Minimum Cathode Current For Regulation VKA = Vref (Figure 1) Off–State Cathode Current (Figure 3) VKA = 36 V, Vref = 0 V Dynamic Impedance (Figure 1, Note 3) VKA = Vref, ∆IK = 1.0 mA to 100 mA f ≤ 1.0 kHz Symbol S bl Vref 2.44 2.41 ∆Vref – 2.495 – 7.0 2.55 2.58 – 2.44 2.423 – 2.495 – 3.0 2.55 2.567 – mV Min Typ Max Min TL431C Typ Max Unit V DVref DVKA – – 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 NOTES: 1. Tlow = –40°C for TL431AIP TL431AILP, TL431IP, TL431ILP, TL431BID, TL431BIP, TL431BILP, TL431AIDM, TL431IDM, TL431BIDM = 0°C for TL431ACP, TL431ACLP, TL431CP, TL431CLP, TL431CD, TL431ACD, TL431BCD, TL431BCP, TL431BCLP, TL431CDM, TL431ACDM, TL431BCDM Thigh = +85°C for TL431AIP, TL431AILP, TL431IP, TL431ILP, TL431BID, TL431BIP, TL431BILP, TL431IDM, TL431AIDM, TL431BIDM = +70°C 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, αVref is defined as: D Vref ppm V ref _C x 10 6 ref D TA (V @ 25_C) A ref αVref can be positive or negative depending on whether Vref Min or Vref Max occurs at the lower ambient temperature. (Refer to Figure 6.) + V ref @ 25_C X 10 6 +DT V ref D V Example : DV V + 8.0 mV and slope is positive, @ 25_C + 2.495 V, DT + 70_C ref A ref a 3. The dynamic impedance ZKA is defined as |Z KA| 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 KA | + DDVIKA + 0.008 x 106 + 45.8 ppm _C 70 (2.495) [ |ZKA| 1 ) R1 R2 MOTOROLA ANALOG IC DEVICE DATA 3 TL431, A, B Series ELECTRICAL CHARACTERISTICS (TA = 25°C, unless otherwise noted.) TL431AI Characteristic Ch ii Reference Input Voltage (Figure 1) VKA = Vref, IK = 10 mA TA = 25°C TA = Tlow to Thigh Reference Input Voltage Deviation Over Temperature Range (Figure 1, Notes 1, 2) VKA= Vref, IK = 10 mA 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 Reference Input Current (Figure 2) IK = 10 mA, R1 = 10 k, R2 = ∞ TA = 25°C TA = Tlow to Thigh (Note 1) Reference Input Current Deviation Over Temperature Range (Figure 2, Note 1) IK = 10 mA, R1 = 10 k, R2 = ∞ Minimum Cathode Current For Regulation VKA = Vref (Figure 1) Off–State Cathode Current (Figure 3) VKA = 36 V, Vref = 0 V Dynamic Impedance (Figure 1, Note 3) VKA = Vref, ∆IK = 1.0 mA to 100 mA f ≤ 1.0 kHz Symbol S bl Vref 2.47 2.44 ∆Vref – 2.495 – 7.0 2.52 2.55 – 2.47 2.453 – 2.495 – 3.0 2.52 2.537 – 2.483 2.475 – 2.495 2.495 3.0 2.507 2.515 – mV Min Typ Max Min TL431AC Typ Max Min TL431B Typ Max Unit V DVref DVKA – – ∆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 NOTES: 1. Tlow = –40°C for TL431AIP TL431AILP, TL431IP, TL431ILP, TL431BID, TL431BIP, TL431BILP, TL431AIDM, TL431IDM, TL431BIDM = 0°C for TL431ACP, TL431ACLP, TL431CP, TL431CLP, TL431CD, TL431ACD, TL431BCD, TL431BCP, TL431BCLP, TL431CDM, TL431ACDM, TL431BCDM Thigh = +85°C for TL431AIP, TL431AILP, TL431IP, TL431ILP, TL431BID, TL431BIP, TL431BILP, TL431IDM, TL431AIDM, TL431BIDM = +70°C 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, αVref is defined as: D Vref ppm V ref _C V x 10 6 ref (V @ 25_C) A A ref αVref can be positive or negative depending on whether Vref Min or Vref Max occurs at the lower ambient temperature. (Refer to Figure 6.) + V ref @ 25_C X 10 6 D T +DT V ref D Example : DV V + 8.0 mV and slope is positive, @ 25_C + 2.495 V, DT + 70_C ref A ref a 3. The dynamic impedance ZKA is defined as |Z KA| 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 KA | + DDVIKA + 0.008 x 106 + 45.8 ppm _C 70 (2.495) [ |ZKA| 1 ) R1 R2 4 MOTOROLA ANALOG IC DEVICE DATA TL431, A, B Series Figure 1. Test Circuit for VKA = Vref Input VKA Figure 2. Test Circuit for VKA > Vref Input R1 Iref IK VKA Figure 3. Test Circuit for Ioff Input Ioff VKA IK Vref R2 Vref V KA + Vref 1 ) R1 ) Iref S R1 R2 Figure 4. Cathode Current versus Cathode Voltage 150 IK , CATHODE CURRENT (mA) IK , CATHODE CURRENT ( µA) 100 50 0 –50 –100 –2.0 VKA = Vref TA = 25°C Input VKA IK 800 600 Input 400 200 0 Figure 5. Cathode Current versus Cathode Voltage VKA = Vref TA = 25°C VKA IK IMin –1.0 0 1.0 2.0 3.0 –200 –1.0 0 1.0 VKA, CATHODE VOLTAGE (V) 2.0 3.0 VKA, CATHODE VOLTAGE (V) Figure 6. Reference Input Voltage versus Ambient Temperature Vref , REFERENCE INPUT VOLTAGE (mV) 2580 2560 2540 2520 2500 2480 2460 2440 2420 2400 –55 –25 0 25 50 75 100 125 Vref Min = 2440 mV Vref Typ = 2495 mV Input Vref Iref , REFERENCE INPUT CURRENT ( µA) 2600 VKA IKVKA = Vref IK = 10 mA 3.0 2.5 2.0 1.5 Figure 7. Reference Input Current versus Ambient Temperature Vref Max = 2550 mV IK = 10 mA 1.0 0.5 0 –55 –25 0 25 50 75 100 125 Input 10k Iref VKA IK TA, AMBIENT TEMPERATURE (°C) TA, AMBIENT TEMPERATURE (°C) MOTOROLA ANALOG IC DEVICE DATA 5 TL431, A, B Series Figure 8. Change in Reference Input Voltage versus Cathode Voltage ∆ Vref , REFERENCE INPUT VOLTAGE (mV) IK = 10 mA TA = 25°C –8.0 Ioff , OFF–STATE CATHODE CURRENT (nA) 0 1.0 k 100 10 1.0 0.1 0.01 –55 VKA = 36 V Vref = 0 V VKA Ioff Figure 9. Off–State Cathode Current versus Ambient Temperature –16 Input R1 IK Vref VKA Input –24 R2 –32 0 10 20 30 40 –25 0 25 50 75 100 125 VKA, CATHODE VOLTAGE (V) TA, AMBIENT TEMPERATURE (5C) Figure 10. Dynamic Impedance versus Frequency 100 |ZKA|, DYNAMIC IMPEDANCE (Ω ) 1.0 k 50 10 – + Output IK Gnd |ZKA|, DYNAMIC IMPEDANCE (Ω ) TA = 25_C ∆ IK = 1.0 mA to 100 mA 0.320 0.300 0.280 0.260 0.240 0.220 0.200 –55 Figure 11. Dynamic Impedance versus Ambient Temperature VKA = Vref ∆ IK = 1.0 mA to 100 mA f ≤ 1.0 kHz Output 1.0 k IK 50 – + Gnd 1.0 0.1 1.0 k 10 k 100 k f, FREQUENCY (MHz) 1.0 M 10 M –25 0 25 50 75 100 125 TA, AMBIENT TEMPERATURE (_C) Figure 12. Open–Loop Voltage Gain versus Frequency A VOL, OPEN LOOP VOLTAGE GAIN (dB) 60 50 40 30 20 10 0 –10 1.0 k 10 k 100 k f, FREQUENCY (MHz) 1.0 M 10 M 0 10 IK = 10 mA TA = 25_C 9.0 µF 15 k 8.25 k Gnd IK Output NOISE VOLTAGE (nV/ √Hz) 230 60 80 Figure 13. Spectral Noise Density 40 Input 20 VKA = Vref IK = 10 mA TA = 25°C IK Output 100 1.0 k f, FREQUENCY (Hz) 10 k 100 k 6 MOTOROLA ANALOG IC DEVICE DATA TL431, A, B Series Figure 14. Pulse Response 3.0 VOLTAGE SWING (V) 2.0 1.0 0 5.0 0 0 4.0 Input 8.0 t, TIME (µs) 12 16 20 TA = 25_C Output 140 220 Output 50 Gnd IK , CATHODE CURRENT (mA) Input Monitor Pulse Generator f = 100 kHz 120 100 80 Stable 60 40 20 0 100 pF 1000 pF 0.01 µF 0.1 µF 1.0 µF 10 µF D C 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 = 25°C Stable A B B A Figure 15. Stability Boundary Conditions CL, LOAD CAPACITANCE Figure 16. Test Circuit For Curve A of Stability Boundary Conditions 150 IK V+ CL Figure 17. Test Circuit For Curves B, C, And D of Stability Boundary Conditions 150 IK V+ 10 k CL TYPICAL APPLICATIONS Figure 18. Shunt Regulator V+ R1 Vout Figure 19. High Current Shunt Regulator V+ R1 Vout R2 R2 V out + 1 ) R1 R2 V ref V out + 1 ) R1 R2 V ref MOTOROLA ANALOG IC DEVICE DATA 7 TL431, A, B Series Figure 20. Output Control for a Three–Terminal Fixed Regulator MC7805 Out In Common R1 Figure 21. Series Pass Regulator V+ Vout R1 V+ Vout R2 R2 + 1 ) R1 Vref R2 V out min + V ) 5.0V ref V out V out + 1 ) R1 Vref R2 V out min + V ) V ref be Figure 22. Constant Current Source RCL Figure 23. Constant Current Sink Isink V+ Iout V+ I I out V + Rref Sink + VRref S CL RS Figure 24. TRIAC Crowbar V+ R1 Vout V+ Figure 25. SRC Crowbar Vout R1 R2 R2 V out(trip) + 1) R1 V ref R2 V out(trip) + 1 ) R1 R2 V ref 8 MOTOROLA ANALOG IC DEVICE DATA TL431, A, B Series Figure 26. Voltage Monitor V+ l R1 R3 Vout Figure 27. Single–Supply Comparator with Temperature–Compensated Threshold V+ Vout Vin R2 R4 Vth = Vref Vin < Vref > Vref V V ref ref Vout V+ ≈ 2.0 V 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 Figure 28. Linear Ohmmeter 25 V 1N5305 2.0 mA 10 k Calibrate 25 V – LM11 + Figure 29. Simple 400 mW Phono Amplifier 38 V Tl = 330 to 8.0 Ω TI 8.0 Ω 360 k 1.0 µF Vout * Thermalloy * THM 6024 * Heatsink on * LP Package * 0.05 µF Tone 25 k Volume 47 k 330 5.0 k 1% 50 k 1% 10 kΩ V 500 k 1% 5.0 M 1% 1.0 MΩ V + 470 µF 1.0 kΩ V 100 kΩ V Range RX Rx + Vout D W V –5.0 V Range 56 k 10 k MOTOROLA ANALOG IC DEVICE DATA 9 TL431, A, B Series Figure 30. High Efficiency Step–Down Switching Converter 150 mH @ 2.0 A TIP115 1.0 k 4.7 k MPSA20 2200 µF 4.7 k 0.1 µF 2.2 k 10 51 k 4.7 k 1N5823 0.01µF 100 k 470 µF + Vout = 5.0 V Iout = 1.0 A Vin = 10 V to 20 V + Test Line Regulation Load Regulation Output Ripple Output Ripple Efficiency Conditions Vin = 10 V to 20 V, Io = 1.0 A Vin = 15 V, Io = 0 A to 1.0 A Vin = 10 V, Io = 1.0 A Vin = 20 V, Io = 1.0 A Vin = 15 V, Io = 1.0 A Results 53 mV (1.1%) 25 mV (0.5%) 50 mVpp P.A.R.D. 100 mVpp P.A.R.D. 82% 10 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) where IC is the device cathode current and Gm is in mhos Go = 1.25 (Vcp2) µmhos. 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 2p * 1.0 M * 20 pF GM P1 P2 + 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 LL Also, the transfer dc voltage gain of the TL431 is: + G Example 1: I C + GMRGMGoRL + 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 + ) ) ) + + + 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. MOTOROLA ANALOG IC DEVICE DATA 11 TL431, A, B Series Figure 31. Simplified TL431 Device Model VCC RL Input 15 k 9.0 mF Ref 1 500 k 8.25 k CL 3 Cathode RP2 10 M Rref 16 GM RGM 1.0 M CP1 20 pF RZ1 15.9 k Go 1.0 mmho CP2 0.265 pF Vref 1.78 V + – Anode 2 Figure 32. Example 1 Circuit Open Loop Gain Plot TL431 OPEN–LOOP VOLTAGE GAIN VERSUS FREQUENCY 60 Av, OPEN–LOOP VOLTAGE GAIN (dB) 50 40 30 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. Figure 33. Example 2 Circuit Open Loop Gain Plot TL431 OPEN–LOOP BODE PLOT WITH LOAD CAP 80 Av, OPEN–LOOP GAIN (dB) 20 10 0 –10 –20 101 102 103 104 105 106 107 60 40 20 0 –20 f, FREQUENCY (Hz) 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: Example 2. 101 102 103 104 105 106 f, FREQUENCY (Hz) + 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 + ) ) ) 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. ) 12 MOTOROLA ANALOG IC DEVICE DATA TL431, A, B Series OUTLINE DIMENSIONS LP SUFFIX PLASTIC PACKAGE CASE 29–04 (TO–92) ISSUE AE A R P SEATING PLANE B F L K 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. DIM A B C D F G H J K L N P R V 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 ––– XX G H V 1 D J C SECTION X–X N N 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. 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 –B– 1 4 F NOTE 2 –A– L C –T– SEATING PLANE J N D K M M TA B H G 0.13 (0.005) M M MOTOROLA ANALOG IC DEVICE DATA 13 TL431, A, B Series OUTLINE DIMENSIONS DM SUFFIX PLASTIC PACKAGE CASE 846A–02 (Micro–8) ISSUE D –A– K –B– 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. 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 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 PIN 1 ID G D 8 PL 0.08 (0.003) M TB S A S –T– SEATING PLANE 0.038 (0.0015) H C J L DIM A B C D G H J K L D SUFFIX PLASTIC PACKAGE CASE 751–06 (SOP–8) ISSUE T A 8 D 5 C E 1 4 H 0.25 M B M h B C e A SEATING PLANE X 45 _ 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. DIM A A1 B C D E e H h L 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_ q L 0.10 A1 B 0.25 M CB S A S q 14 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 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/ JAPAN: Nippon Motorola Ltd.: SPD, Strategic Planning Office, 141, 4–32–1 Nishi–Gotanda, Shagawa–ku, Tokyo, Japan. 03–5487–8488 16 ◊ MOTOROLA ANALOG IC DEVICE DATA TL431/D