PROGRAMMABLE PRECISION SHUNT REGULATOR PROGRAMMABLE PRECISION REFERENCES TL431Z/AZ /CZ TO-92 PKG The TL431Z is three-terminal adjustable shunt regulator with specified termal stability. The output voltage may be set to any value between VREF(Approx. 2.5V) and 36V with two external resistors. This device has a typical output inpedance of 0.2. Active output circuitry provides a very sharp turn-on characteristic, making this device excellent replacement for zener diodes in many application. 3.Cathode 2.Anode 1.Reference SOT-23 PKG 2.Anode 1.Reference 3.Cathode FEATURES Equivalent Full Range Temperature Coefficient 50PPM/ Temperature Compensated For Operation Over Full Rate Operating Temperature Range Adjustable Output Voltage Fast Turn-on Response Sink Current Capability 1 to 100 Low (0.2 Typ.) Dynamic Output Impedance Low Output Noise ORDERING INFORMATION Device TL431Z TL431-AZ TL431-CZ TL431ZSF TL431-AZSF TL431-CZSF Marking TL431Z TL431-AZ TL431-CZ 431 Package * Packing label is different as Vref SOT-23 TO-92 FUNCTION BLOCK DIAGRAM BLOCK DIAGRAM CATHODE(K) CATHODE REFERENCE 2.5VREF REFERENCE(R) ANODE(A) ANODE HTC Jan. 2007 - Rev 1.0 1 PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ EQUIVALENT SCHEMATIC - All component values are nominal RECOMMENDED OPERATING CONDITIONS CHARACTERISTIC Cathode Voltage Cathode Current SYMBOL VKA MIN. VREF IK 1 MAX. UNIT 36 100 V DISSIPATION RATING TABLE1-FREE-AIR TEMPERATURE Package TO-92 SOT-23 TA=25 Power Rating Derating Factor Above TA=25 770 230 6.2/ 1.8/ TA=70 TA=85 TA=125 Power Rating Power Rating Power Rating 398 491 149 122 - HTC Jan. 2007 - Rev 1.0 2 PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ ABSOLUTE MAXIMUM RATINGS (Full Operating Ambient Temperature Range Applies Unless Otherwise Noted) SYMBOL RATING UNIT Cathode Voltage VKA 37 V Continuous Cathode Current Range IKA -100 ~ +150 Reference Input Current Range IREF 2~4 TJ 150 Operating Temperature TOPR -40 ~ 85 Storage Temperature TSTG -65 ~ 150 Thermal Resistance Junction to Ambient JA CHARACTERISTIC Junction Temperature TO-92 PKG = 178 TL431Z ELECTRICAL CHARACTERISTICS CHARACTERISTIC Reference Input Voltage 1 TEST CONDITION VKA=VREF, IK=10 MIN. TYP. MAX. UNIT 2.440 2.495 2.550 V 3 17 -1.4 -2.7 VKA=VREF, IK=10 Deviation of Reference Input Voltage Over (TA=25, unless otherwise specified) SYMBOL CIR-CUIT VREF /W SOT-23 PKG = 625 VREF/T 1 TA=Full Range Full Temperature Range Ratio of Change in Reference Input Voltage VKA=10V-V REF VREF/VKA 2 to the Change in Cathod IK=10 VKA=36V-10V Voltage Reference Input Current IREF 2 IKA=10, R1=10, R2= -1 -2 2.0 4 0.4 1.2 0.4 1 0.1 1 0.2 0.5 IK=10, R1=10, R2= Deviation of Reference Input Current Over Full /V IREF/T 2 IKAMIN 1 IKAOFF 3 ZKA 1 TA=Full Range Temperature Range Minimum Cathode Current for Regulation Off-State Cathode Current Dynamic Impedance VKA=VREF VKA=36V, V REF=0 VKA=VREF, IK=1~100, f1 HTC Jan. 2007 - Rev 1.0 3 PROGRAMMABLE PRECISION SHUNT REGULATOR TL431AZ ELECTRICAL CHARACTERISTICS CHARACTERISTIC Reference Input Voltage Deviation of Reference Input Voltage Over Full Temperature Range Ratio of Change in Reference Input Voltage to the Change in Cathod Voltage Reference Input Current Deviation of Reference Input Current Over Full Temperature Range Minimum Cathode Current for Regulation Off-State Cathode Current Dynamic Impedance SYMBOL CIR-CUIT VREF 1 VREF/T VREF/VKA 1 2 IREF 2 IREF/T 2 IKAMIN 1 IKAOFF 3 ZKA 1 (TA=25, unless otherwise specified) TEST CONDITION VKA=VREF, IK=10 VKA=VREF, IK=10 TA=Full Range TYP. 2.495 MAX. 2.520 UNIT V 3 17 VKA=10V-V REF -1.4 -2.7 VKA=36V-10V -1 -2 2.0 4 0.4 1.2 0.4 1 0.1 1 0.2 0.5 /V IKA=10, R1=10, R2= IK=10, R1=10, R2= TA=Full Range VKA=VREF VKA=36V, V REF=0 VKA=VREF, IK=1~100, f1 Reference Input Voltage SYMBOL CIR-CUIT VREF 1 (TA=25, unless otherwise specified) TEST CONDITION MIN. TYP. MAX. UNIT 2.482 2.495 2.508 V 3 17 VKA=10V-V REF -1.4 -2.7 VKA=36V-10V -1 -2 2.0 4 0.4 1.2 0.4 1 0.1 1 0.2 0.5 VKA=VREF, IK=10 VKA=VREF, IK=10 Deviation of Reference Input Voltage Over MIN. 2.470 IK=10 TL431CZ ELECTRICAL CHARACTERISTICS CHARACTERISTIC TL431Z/AZ /CZ VREF/T 1 TA=Full Range Full Temperature Range Ratio of Change in Reference Input Voltage to the Change in Cathod VREF/VKA 2 IK=10 Voltage Reference Input Current IREF 2 IKA=10, R1=10, R2= IK=10, R1=10, R2= Deviation of Reference Input Current Over Full /V IREF/T 2 IKAMIN 1 IKAOFF 3 ZKA 1 TA=Full Range Temperature Range Minimum Cathode Current for Regulation Off-State Cathode Current Dynamic Impedance VKA=VREF VKA=36V, V REF=0 VKA=VREF, IK=1~100, f1 HTC Jan. 2007 - Rev 1.0 4 PROGRAMMABLE PRECISION SHUNT REGULATOR Fig. 1 Test Circuit for V INPUT KA =V REF Fig. 2 Test Circuit for V VKA IKA TL431Z/AZ /CZ INPUT R1 DUT R2 VREF KA V REF VKA IKA REF DUT VREF VKA=VREF(1+R1/R2)+IREF R1 Fig. Test Circuit for IKA off) VKA INPUT IKA DUT HTC Jan. 2007 - Rev 1.0 5 PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ The deviation parameters V REF(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, V REF, is defined as : Maximum V REF V I(dev) 6 x10 VREF ppm = VREF at 25 TA VI(dev) Minimum V REF TA Where : TA is the recommended operating free-air temperature range of the device. VREF can be positive or negative, depending on whether minimum V REF or maximum V REF, respectively, occurs at the lower temperature. Example : Maximum V REF=2496 at 30, maximum VREF=2492 at 0, VREF=2495 at 25, TA=70 for TL431CZ VREF= 4 6 x10 ~ 2495 ~ 23PPM/ 70 Because minimum V REF occurs at the lower temperature, the coefficient is positive. Calculating Dynamic Impedance The dynamic impedance is defined as : ZKA= VKA IKA When the device is operating with two external resistors (see Figure 3), the total dynamic impedance of the circuit is given by : Z'= V I ~ZKA 1+ R1 ~ R2 Figure 1. Calculating deviation parameters and dynamic impedance HTC Jan. 2007 - Rev 1.0 6 PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ TYPICAL PERFORMANCE CHARACTERISTICS REFERENCE VOLTAGE vs FREE-AIR TEMPERATURE REFERENCE CURRENT vs FREE-AIR TEMPERATURE 2600 5 R1=10 R2= IKA=10 2580 VREF=2500 2560 4 VREF-REFERENCE VOLTAGE- VREF-REFERENCE VOLTAGE- 2540 2520 VREF=2495 2500 2480 2460 VREF=2440 2440 3 2 1 2420 2400 0 -75 -50 -25 0 25 50 75 100 125 -75 -50 TA-FREE-AIR TEMPERATURE- -25 0 25 50 75 100 125 TA-FREE-AIR TEMPERATURE- 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 RVEF at IKA=10, TA=25 Figure 4. Figure 5. CATHODE CURRENT vs CATHODE VOLTAGE CATHODE CURRENT vs CATHODE VOLTAGE 150 800 VKA=VERF TA=25 VKA=VREF TA=25 125 600 IKA-CATHODE CURRENT- IKA-CATHODE CURRENT- 100 75 50 25 0 IMIN 400 200 -25 -50 0 -75 -100 -200 -2 -1 0 1 2 3 -1 0 1 VKA-CATHODE VOLTAGE-V VKA-CATHODE VOLTAGE-V Figure 6. Figure 7. 2 3 HTC Jan. 2007 - Rev 1.0 7 PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ TYPICAL PERFORMANCE CHARACTERISTICS OFF-STATE CATHODE CURRENT vs FREE-AIR TEMPERATURE RATIO DELTA REFERENCE VOLTAGE TO DELTA CATHODE VOLTAGE vs FREE-AIR TEMPERATURE 2.5 -0.85 VKA=36 V VKA=3V TO 36V -0.95 VREF/VKA-/V IOFF-OFFSTATE CATHODE CURRENT 2 1.5 -1.05 -1.15 1 -1.25 0.5 -1.35 0 -1.45 -75 -50 -25 0 25 50 75 100 125 -75 TA-FREE-AIR TEMPERATURE- -50 -25 0 25 50 75 100 125 TA-FREE-AIR TEMPERATURE- 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. EQUIVALENT INPUT NOISE VOLTAGE VS FREQUENCY 260 IO=10 TA=25 VIN-EQUIVALENT NOISE VOLTAGE- 240 220 200 180 160 140 120 100 10 100 1K 10K 100K f-FREQUENCY- Figure 10. HTC Jan. 2007 - Rev 1.0 8 PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ TYPICAL PERFORMANCE CHARACTERISTICS 19.1V 1 500 910 VCC 2000 VCC TL431 (DUT) TL2027 AV=10V/ + + 820 16 TO OSCILLOSCOPE 1 - 16 160 16 1 TL2027 22 33 0.1 33 AV=2V/V 910 VEE VEE Figure 11. Test Circuit for Equivalent Input Noise Voltage SMALL-SIGNAL VOLTAGE AMPLIFICATION VS FREQUENCY AV-SMALL-SIGNAL VOLTAGE AMPLIFICATIO 60 IKA=10 TA=25 50 15 OUTPUT 232 IKA 40 9 + 30 ~ 20 8.25 - GND 10 Test Circuit for Voltage Amplification 0 1K 10K 100K 1M 10M f-FREQUENCY- Figure 12. HTC Jan. 2007 - Rev 1.0 9 PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ TYPICAL PERFORMANCE CHARACTERISTICS REFERENCE IMPEDANCE VS FREQUENCY 100 IKA=10 TA=25 ZKA-REFERENCE IMPEDANCE 1 OUTPUT 10 ~ IKA 50 + GND 1 Test Circuit for Reference Impedance 0.1 1K 10K 100K 1M 10M f-FREQUENCY- Figure 13. REFERENCE IMPEDANCE VS FREQUENCY 6 TA=25 INPUT 220 ZKA-REFERENCE IMPEDANCE 5 OUTPUT 4 PULSE GENERATOR f=100 3 50 OUTPUT GND 2 1 Test Circuit for Pulse Response 0 -1 0 1 2 3 4 5 6 7 t-TIME- Figure 14. HTC Jan. 2007 - Rev 1.0 10 PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ APPLICATION INFORMATION R (SEE NOTE A) VO VI(BATT) R1 0.1% VREF VO =1+ TL431 R1 VREF R2 R2 0.1% RETURN NOTE A : R Should provide cathode current1 to the TL431 at minimum VI(BATT) Figure 15. Shunt Regulator VI(BATT) VO TL431 VON ~ ~ 2.5V INPUT VOFF ~ ~ VI(BATT) VIT ~ ~ 2.5V GND Figure 16. Single-Supply Comparator With Temperature-Compensated Threshold VI(BATT) R (SEE NOTE A) 2N222 2N222 30 4.7 VO =1+ R1 VREF R2 0.01 VO TL431 R2 0.1% R1 0.1% NOTE A : R Should provide cathode current1 to the TL431 at minimum VI(BATT) Figure 17. Precision High-Current Series Regulator HTC Jan. 2007 - Rev 1.0 11 PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ APPLICATION INFORMATION VI(BATT) IN LM7805 OUT VO R1 COMMON VO =1+ TL431 R1 V R2 REF MINIMUM V O=VREF+5V R2 Figure 18. Output Control of a 3-Terminal Fixed Regulator VO VI(BATT) R1 VO =1+ R2 R1 R2 VREF TL431 RETURN Figure 19. High-Current Shunt Regulator VO VI(BATT) R1 TL431 C (SEE NOTE A) R2 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 12 HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ APPLICATION INFORMATION IN VI(BATT) 8.2 LM317 OUT Adjust VO ~ ~ 5V, 1.5A 243 0.1% TL431 243 0.1% Figure 21. Precision 5-V 1.5A Regulator VO ~ ~ 5V VI(BATT) RB (SEE NOTE A) 27.4 0.1% TL431 27.4 0.1% NOTE A : RB Should provide cathode current1 to the TL431. Figure 22. Efficient 5-V Precision Regulator 12V 6.8 5V 10 10 0.1% TL431 + X NOT USED TL598 10 0.1% FEED BACK Figure 23. PWM Converter With Reference Jan. 2007 - Rev 1.0 13 HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ APPLICATION INFORMATION R3 (SEE NOTE A) OUT VI(BATT) R1A R4 (SEE NOTE A) R1B LOW LIMIT= 1+ R1B VREF R2B TL431 HIGH LIMIT= 1+ R1A VREF R2A R2A LED ON WHEN LOW LIMIT<VI(BATT)HIGH LIMIT R2B NOTE A : R3 and R4 are selected to provide the desired LED intensity and cathode current 1 to the TL431 at the available VI(BATT). Figure 24. Voltage Monitor 650 12V 2 R TL431 DELAY=RxCxI N ( ON 12V 12V-VREF C OFF Figure 25. Delay Timer RCL 0.1% VI(BATT) R1 TL431 IO IOUT = R1 = VREF RCL + IKA VI(BATT) + IKA IO HFE Figure 26. Precision Current Limiter Jan. 2007 - Rev 1.0 14 HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431Z/AZ /CZ APPLICATION INFORMATION VI(BATT) IO IO = VREF RS TL431 RS 0.1% Figure 27. Precision Constant-Current Sink Jan. 2007 - Rev 1.0 15 HTC