TL1431 Programmable voltage reference Features ■ Adjustable output voltage: VREF to 36 V ■ Sink current capability: 1 to 100 mA ■ Typical output impedance: 0.22 Ω ■ 0.4% and 0.25% voltage precision Description The TL1431 is a programmable shunt voltage reference with guaranteed temperature stability over the entire operating temperature range. Z TO92 (Plastic package) The output voltage may be set to any value between 2.5 V and 36 V with two external resistors. The TL1431 operates with a wide current range from 1 to 100 mA with a typical dynamic impedance of 0.2 Ω. March 2008 D SO-8 (Batwing plastic micropackage) Rev 4 1/16 www.st.com 16 Schematic diagrams 1 TL1431 Schematic diagrams Figure 1. TO92 pin connections (top view) Cathode Anode Reference 1 Figure 2. 2 3 SO-8 pin connections (top view) 8 7 6 5 1 - Cathode 2 - Anode 3 - Anode 4 - N.C. 5 - N.C. 6 - Anode 7 - Anode 8 - Reference 1 Figure 3. 2 3 TL1431 block diagram Cathode Vref + Vref Anode 2/16 4 TL1431 2 Absolute maximum ratings and operating conditions Absolute maximum ratings and operating conditions Table 1. Absolute maximum ratings Symbol VKA Parameter Cathode to anode voltage Value Unit 37 V Ik Continuous cathode current range -100 to +150 mA Iref Reference input current range -0.05 to +10 mA Tj Junction temperature +150 °C 625 960 mW (1) Pd Power dissipation TO92 SO-8 batwing Tstg Storage temperature range -65 to +150 °C HBM: human body model (2) 2000 200 1500 V ESD MM: machine model (3) CDM: charged device model (4) 1. Calculated with Tj=+150°C and Tamb=+25°C with relative Rthja depending on the package. 2. Human body model: A 100 pF capacitor is charged to the specified voltage, then discharged through a 1.5 kΩ resistor between two pins of the device. This is done for all couples of connected pin combinations while the other pins are floating. 3. Machine model: A 200 pF capacitor is charged to the specified voltage, then discharged directly between two pins of the device with no external series resistor (internal resistor < 5 Ω). This is done for all couples of connected pin combinations while the other pins are floating. 4. Charged device model: all pins and the package are charged together to the specified voltage and then discharged directly to the ground through only one pin. This is done for all pins. Table 2. Operating conditions Symbol VKA Ik Parameter Value Unit Cathode to anode voltage Vref to 36 V Cathode current 1 to 100 mA -20 to +70 -40 to +105 °C 130 200 °C/W Toper Operating free-air temperature range TL1431C/AC TL1431I/AI Rthja Thermal resistance junction to ambient SO-8 batwing TO92 3/16 Electrical characteristics TL1431 3 Electrical characteristics Table 3. Tamb = 25°C (unless otherwise specified) TL1431C Symbol TL1431AC Parameter Unit Min. Typ. Max. Min. Typ. Max. Vref Reference input voltage - see Figure 4 VKA = Vref , Ik = 10 mA ΔVref Reference input voltage deviation over temperature range (1) - see Figure 4 VKA = Vref, Ik = 10 mA, Tmin ≤ Tamb ≤ Tmax 3 20 3 20 mV Temperature coefficient of reference input voltage(2) VKA = Vref, Ik = 10 mA, Tmin ≤Tamb ≤ Tmax ±13 ±90 ±13 ±90 ppm/°C ΔVref ---------------ΔT ΔVref ---------------ΔVka Ratio of change in reference input voltage to change in cathode to anode voltage - see Figure 5 Ik = 10mA - ΔVKA = 36V to 3V 2.490 2.500 2.510 2.493 2.500 2.507 -2 -1.1 -2 -1.1 V mV/V Reference input current Ik = 10mA, R1 = 10kΩ, R2 = ∞ Tmin ≤ Tamb ≤ Tmax 1.5 2.5 3 1.5 2.5 3 µA ΔIref Reference input current deviation over temperature range Ik = 10mA, R1 = 10kΩ, R2 =∞, Tmin ≤ Tamb ≤ Tmax 0.2 1.2 0.2 1.2 µA Imin Minimum cathode current for regulation - Figure 4 VKA = Vref 0.5 1 0.5 0.6 mA Ioff Off-state cathode current - see Figure 6 180 500 180 500 nA 0.2 0.5 0.2 0.5 Ω Iref (3) ⏐ ZKA⏐ Dynamic impedance VKA = Vref , ΔIk = 1 to100mA, f ≤ 1kHz 1. See Reference input voltage deviation over temperature range in Section 4: Parameter definitions on page 9. 2. See Temperature coefficient of reference input voltage in Section 4: Parameter definitions on page 9. 3. See Dynamic impedance in Section 4: Parameter definitions on page 9. 4/16 TL1431 Table 4. Electrical characteristics Tamb = 25°C (unless otherwise specified) TL1431I Symbol TL1431AI Parameter Unit Min. Typ. Max. Min. Typ. Vref Reference input voltage - see Figure 4 VKA = Vref , Ik = 10 mA ΔVref Reference input voltage deviation over temperature range (1) - see Figure 4 VKA = Vref, Ik = 10 mA, Tmin ≤ Tamb ≤ Tmax 7 30 7 Temperature coefficient of reference input voltage(2) VKA = Vref, Ik = 10 mA, Tmin ≤ Tamb ≤ Tmax ±22 ±100 ±22 ΔVref ---------------ΔT ΔVref ---------------ΔVka Ratio of change in reference input voltage to change in cathode to anode voltage - see Figure 5 Ik = 10mA - ΔVKA = 36V to 3V Max. 2.490 2.500 2.510 2.493 2.500 2.507 -2 -1.1 -2 30 V mV ±100 ppm/°C -1.1 mV/V Reference input current Ik = 10mA, R1 = 10kΩ, R2 = ∞ Tmin ≤ Tamb ≤ Tmax 1.5 2.5 3 1.5 2.5 3 µA ΔIref Reference input current deviation over temperature range Ik = 10mA, R1 = 10kΩ, R2 =∞, Tmin ≤ Tamb ≤ Tmax 0.5 1 0.8 1.2 µA Imin Minimum cathode current for regulation - see Figure 4 VKA = Vref 0.5 1 0.5 0.7 mA Ioff Off-state cathode current - see Figure 6 180 500 180 500 nA Dynamic impedance (3) VKA = Vref , ΔIk= 1 to100mA, f ≤ 1kHz 0.2 0.5 0.2 0.5 Ω Iref ⏐ ZKA⏐ 1. See Reference input voltage deviation over temperature range in Section 4: Parameter definitions on page 9. 2. See Temperature coefficient of reference input voltage in Section 4: Parameter definitions on page 9. 3. See Dynamic impedance in Section 4: Parameter definitions on page 9. 5/16 Electrical characteristics Figure 4. TL1431 Test circuit for VKA = VREF Figure 5. Test circuit for VKA = VREF Input Input R Output R IK Output R1 IK=10mA VKA IREF R2 VKA VREF VREF R1 VKA = VREF ( 1 + -------- ) + R1 x IREF R2 Figure 6. Test circuit for IOFF Figure 7. Test circuit for phase margin and voltage gain VKA=36V 10μF 10μF Figure 8. Test circuit for response time Figure 9. Output 8.25kΩ Input IK=10mA 15kΩ IOFF VREF Reference voltage vs. temperature 1 mA 0 mA Output IK=1mA Reference voltage (V) 2.500 2.498 2.496 2.494 2.492 IK=10 mA VKA=VREF=2.5 V See figure 1 2.490 2.488 2.486 -40 -20 0 20 40 60 Temperature (°C) 6/16 80 100 120 TL1431 Electrical characteristics Figure 10. Reference voltage vs. cathode current Figure 11. Reference voltage vs. cathode current 3.0 Reference voltage (V) Reference voltage (V) 3 2 VKA=VREF See figure 1 1 0 2.5 2.0 VKA=VREF See figure 1 1.5 1.0 0.5 -1 -40 -20 0 20 40 60 80 0.0 0.0 100 0.2 0.4 Cathode current (mA) 0.6 Figure 12. Reference current vs. temperature 0.10 VKA = 36V See figure 3 0.08 IOFF (µA) IREF (µA) 1.5 1.0 IK=10 mA VKA=VREF See figure 1 0.5 -20 0 20 40 60 80 0.06 0.04 0.02 100 0.00 -40 120 -20 0 Temperature (°C) 40 60 80 100 120 Figure 15. Drift of RKA vs. temperature 0.00 0.0 IK=10 mA VKA=VREF See figure 2 -0.5 IK=10 mA VKA=VREF= 2.5V see figure 1 -0.01 Δ RKA (Ω ) ΔVREF / ΔVKA (mV / V) 20 Temperature(°C) Figure 14. Ratio of change in VREF to change in VKA vs. temperature -1.0 -1.5 -2.0 -40 1.0 Figure 13. Off-state cathode current vs. temperature 2.0 0.0 -40 0.8 Cathode current (mA) -0.02 -0.03 -20 0 20 40 60 Temperature (°C) 80 100 120 -0.04 -40 -20 0 20 40 60 80 100 120 Temperature (°C) 7/16 Electrical characteristics TL1431 Figure 16. Maximum operating current vs. temperature Figure 17. Gain and phase vs. frequency 0.52 60 200 IK=10 mA See figure 4 Gain 0.50 40 150 100 Gain (dB) IK=IMIN VKA=VREF See figure 1 0.46 50 Phase 20 0 0 -50 0.44 -100 -20 0.42 -150 0.40 -40 -40 -20 0 20 40 60 80 100 120 1 10 100 Frequency (kHz) Temperature (°C) Figure 18. Stability behavior with capacitive loads -200 10000 1000 Figure 19. Maximum power dissipation 100 100 TAMB= +25°C 80 VKA=5V 60 Stable Area Cathode current (mA) Cathode current (mA) VKA=VREF Stable Area Instable Area VKA=12V 40 VKA=24V 0 1E-10 1E-8 1E-7 1E-6 1E-5 Figure 20. Pulse response for IK = 1 mA 6 Voltage (V) Current step: 1 mA 4 TAMB=+25°C See figure 6 Output voltage 2 0 1 2 3 Time (µs) 8/16 TO92 40 0 1E-9 Capacitive Load (F) 0 60 20 20 4 5 SO8 Batwing 80 Safe Area 10 20 Cathode voltage (V) 30 Phase (°) IMIN (mA) 0.48 TL1431 4 Parameter definitions Parameter definitions Reference input voltage deviation over temperature range ΔVref is defined as the difference between the maximum and minimum values obtained over the full temperature range. ΔVref = Vref max. - Vref min. Figure 21. Reference input voltage deviation over temperature range V ref max. V ref min. Temperature T2 T1 Temperature coefficient of reference input voltage The temperature coefficient is defined as the slopes (positive and negative) of the voltage versus temperature limits within which the reference is guaranteed. Figure 22. Temperature coefficient of reference input voltage -n p pm Max 2.5V min /°C C m/° p +n p Temperature 25°C Dynamic impedance ΔV KA The dynamic impedance is defined as | ZKA| = --------------Δ IK 9/16 Package information 5 TL1431 Package information In order to meet environmental requirements, ST offers these devices in ECOPACK® packages. These packages have a lead-free second level interconnect. The category of second level interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are available at: www.st.com. 10/16 TL1431 5.1 Package information SO-8 batwing package information Figure 23. SO-8 batwing package mechanical drawing Table 5. SO-8 batwing package mechanical data Dimensions Ref. Millimeters Min. Typ. A Inches Max. Min. Typ. 1.75 0.069 A1 0.10 A2 1.25 b 0.28 0.48 0.011 0.019 c 0.17 0.23 0.007 0.010 D 4.80 4.90 5.00 0.189 0.193 0.197 E 5.80 6.00 6.20 0.228 0.236 0.244 E1 3.80 3.90 4.00 0.150 0.154 0.157 e 0.25 Max. 0.004 0.010 0.049 1.27 0.050 h 0.25 0.50 0.010 0.020 L 0.40 1.27 0.016 0.050 k 1° 8° 1° 8° ccc 0.10 0.004 11/16 Package information 5.2 TL1431 TO92 (ammopack and tape and reel) package information Figure 24. TO-92 ammopack and tape and reel package mechanical drawing A1 P T P A H W2 W0 W W1 H0 I1 H L1 H1 d D0 F1 F2 P2 P0 Table 6. TO-92 ammopack and tape and reel package mechanical data Millimeters Inches Dim. Min Typ. Min. Typ. Max. AL 5.0 0.197 A 5.0 0.197 T 4.0 0.157 d 0.45 0.018 I1 2.5 P 11.7 12.7 13.7 0.461 0.500 0.539 PO 12.4 12.7 13 0.488 0.500 0.512 P2 5.95 6.35 6.75 0.234 0.250 0.266 F1/F2 2.4 2.5 2.8 0.094 0.098 0.110 Δh -1 0 1 -0.039 0 0.039 ΔP -1 0 1 -0.039 0 0.039 W 17.5 18.0 19.0 0.689 0.709 0.748 W0 5.7 6 6.3 0.224 0.236 0.248 W1 8.5 9 9.75 0.335 0.354 0.384 0.098 W2 0.5 0.020 H 20 0.787 H0 15.5 16 H1 DO L1 12/16 Max. 16.5 0.610 0.630 25 3.8 4.0 4.2 11 0.650 0.984 0.150 0.157 0.165 0.433 TL1431 5.3 Package information TO92 (bulk) package information Figure 25. TO-92 bulk package mechanical drawing Table 7. TO-92 bulk package mechanical data Millimeters Inches Dim. Min L Typ. Max. Min. 1.27 Typ. Max. 0.05 B 3.2 3.7 4.2 0.126 0.1457 0.1654 O1 4.45 5.00 5.2 0.1752 0.1969 0.2047 C 4.58 5.03 5.33 0.1803 0.198 0.2098 K 12.7 O2 0.407 0.0197 0.02 a 0.35 0.5 0.5 0.508 0.016 0.0138 13/16 Ordering information 6 TL1431 Ordering information Table 8. Order codes Order code Temperature range Package Packing SO-8 Tube or tape and reel TL1431CD TL1431CDT 1431C TL1431ACD TL1431ACDT TL1431CZ TL1431CZT TL1431CZ-AP 1431AC -20°C, +70°C TL1431C TO92 TL1431ACZ TL1431ACZT TL1431ACZ-AP 1431I SO-8 TL1431AID TL1431AIDT Tube or tape and reel 1431AI TL1431I -40°C, + 105°C TO92 TL1431AIZ TL1431AIZT TL1431AIZ-AP TL1431IYD(1) TL1431IYDT(1) Bulk or Tape or Ammopack TL1431AC TL1431ID TL1431IDT TL1431IZ TL1431ZT TL1431IZ-AP Marking Bulk or Tape or Ammopack TL1431AI SO-8 (Automotive grade) Tube or tape and reel 1431IY 1. Qualification and characterization according to AEC Q100 and Q003 or equivalent, advanced screening according to AEC Q001 and Q 002 or equivalent are on-going. 14/16 TL1431 7 Revision history Revision history Table 9. Document revision history Date Revision 01-Mar-2002 1 Initial release. 01-Nov-2005 2 PPAP references inserted in the datasheet seeTable 8: Order codes on page 14. 3 Minimum value for temperature range updated in Table 2: Operating conditions. Δ Vref--------------Minimum values added and maximum values deleted for Δ Vka parameter in Table 4 in Section 3: Electrical characteristics. Package information for TO92 tape and reel updated, see Section 5: Package information. Format update. 4 Corrected SO-8 package mechanical data. Corrected footnote for automotive grade order codes in order code table. Corrected packing information for TO92 devices in order code table. 25-Apr-2007 11-Mar-2008 Changes 15/16 TL1431 Please Read Carefully: Information in this document is provided solely in connection with ST products. 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