TL431CDR-J

TL431, TL432 SLVS543Q – AUGUST 2004 – REVISED JULY 2022 TL431, TL432 Precision Programmable Reference 1 Features 3 Description • The TL431LI / TL432LI are pin-to-pin alternatives to TL431 / TL432. TL43xLI offers better stability, lower temperature drift (VI(dev)), and lower reference current (Iref) for improved system accuracy. • • • • • • Reference voltage tolerance at 25°C – 0.5% (B grade) – 1% (A grade) – 2% (Standard grade) Adjustable output voltage: Vref to 36 V Operation from −40°C to 125°C Typical temperature drift (TL43xB) – 6 mV (C temp) – 14 mV (I temp, Q temp) Low Output Noise 0.2-Ω Typical output impedance Sink-current capability: 1 mA to 100 mA 2 Applications • • • • • Adjustable voltage and current referencing Secondary side regulation in flyback SMPSs Zener replacement Voltage monitoring Comparator with integrated reference VKA Input IKA Vref Simplified Schematic The TL431 and TL432 devices are three-terminal adjustable shunt regulators, with specified thermal stability over applicable automotive, commercial, and military temperature ranges. The output voltage can be set to any value between Vref (approximately 2.5 V) and 36 V, with two external resistors. These devices have a typical output impedance of 0.2 Ω. Active output circuitry provides a very sharp turn-on characteristic, making these devices excellent replacements for Zener diodes in many applications, such as onboard regulation, adjustable power supplies, and switching power supplies. The TL432 device has exactly the same functionality and electrical specifications as the TL431 device, but has different pinouts for the DBV, DBZ, and PK packages. Both the TL431 and TL432 devices are offered in three grades, with initial tolerances (at 25°C) of 0.5%, 1%, and 2%, for the B, A, and standard grade, respectively. In addition, low output drift versus temperature ensures good stability over the entire temperature range. The TL43xxC devices are characterized for operation from 0°C to 70°C, the TL43xxI devices are characterized for operation from –40°C to 85°C, and the TL43xxQ devices are characterized for operation from –40°C to 125°C. Device Information PART NUMBER TL43x (1) (1) PACKAGE (PIN) BODY SIZE (NOM) SOT-23-3 (3) 2.90 mm × 1.30 mm SOT-23-5 (5) 2.90 mm × 1.60 mm SOIC (8) 4.90 mm × 3.90 mm PDIP (8) 9.50 mm × 6.35 mm SOP (8) 6.20 mm × 5.30 mm For all available packages, see the orderable addendum at the end of the data sheet. An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 Table of Contents 1 Features............................................................................1 2 Applications..................................................................... 1 3 Description.......................................................................1 4 Revision History.............................................................. 2 5 Device Comparison Table...............................................3 6 Pin Configuration and Functions...................................4 7 Specifications.................................................................. 5 7.1 Absolute Maximum Ratings........................................ 5 7.2 ESD Ratings............................................................... 5 7.3 Thermal Information....................................................5 7.4 Recommended Operating Conditions.........................5 7.5 Electrical Characteristics, TL431C, TL432C............... 6 7.6 Electrical Characteristics, TL431I, TL432I.................. 7 7.7 Electrical Characteristics, TL431Q, TL432Q...............8 7.8 Electrical Characteristics, TL431AC, TL432AC.......... 9 7.9 Electrical Characteristics, TL431AI, TL432AI........... 10 7.10 Electrical Characteristics, TL431AQ, TL432AQ...... 11 7.11 Electrical Characteristics, TL431BC, TL432BC...... 12 7.12 Electrical Characteristics, TL431BI, TL432BI......... 13 7.13 Electrical Characteristics, TL431BQ, TL432BQ......14 8 Parameter Measurement Information.......................... 19 9 Detailed Description......................................................20 9.1 Overview................................................................... 20 9.2 Functional Block Diagram......................................... 20 9.3 Feature Description...................................................21 9.4 Device Functional Modes..........................................21 10 Applications and Implementation.............................. 22 10.1 Application Information........................................... 22 10.2 Typical Applications................................................ 22 10.3 System Examples................................................... 27 11 Power Supply Recommendations..............................30 12 Layout...........................................................................30 12.1 Layout Guidelines................................................... 30 12.2 Layout Example...................................................... 30 13 Device and Documentation Support..........................31 13.1 Device Nomenclature..............................................31 13.2 Related Links.......................................................... 31 13.3 Receiving Notification of Documentation Updates..31 13.4 Support Resources................................................. 31 13.5 Trademarks............................................................. 31 13.6 Electrostatic Discharge Caution..............................32 13.7 Glossary..................................................................32 14 Mechanical, Packaging, and Orderable Information.................................................................... 32 4 Revision History Changes from Revision P (November 2018) to Revision Q (July 2022) Page • Updated the numbering format for tables, figures, and cross-references throughout the document..................1 • Corrected the device names in the Pin Functions table..................................................................................... 4 Changes from Revision O (January 2015) to Revision P (November 2018) Page • Added text to the Description section................................................................................................................. 1 • Added TL43x Device Comparison Table ........................................................................................................... 3 • Added TL43x Device Nomenclature section.....................................................................................................31 Changes from Revision N (January 2014) to Revision O (January 2015) Page • Added Applications, Device Information table, Pin Functions table, ESD Ratings table, Thermal Information table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section.............................................................................. 1 • Added Applications............................................................................................................................................. 1 • Moved Typical Characteristics into Specifications section. ............................................................................0 Changes from Revision M (July 2012) to Revision N (January 2014) Page • Updated document formatting............................................................................................................................ 1 • Removed Ordering Information table..................................................................................................................4 • Added Application Note links............................................................................................................................ 22 2 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 5 Device Comparison Table DEVICE PINOUT INITIAL ACCURACY OPERATING FREE-AIR TEMPERATURE (TA) TL431 TL432 B: 0.5% A: 1% (Blank): 2% C: 0°C to 70°C I: -40°C to 85°C Q: -40°C to 125°C Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 3 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 6 Pin Configuration and Functions TL431, TL431A, TL431B . . . LP (TO-92/TO-226) PACKAGE (TOP VIEW) TL431A, TL431B . . . DCK (SC-70) PACKAGE (TOP VIEW) TL431 . . . KTP (PowerFLEX /TO-252) PACKAGE (TOP VIEW) CATHODE ANODE CATHODE ANODE CATHODE NC REF ANODE REF REF 1 6 2 5 3 4 ANODE NC NC NC − No internal connection TL431, TL431A, TL431B . . . D (SOIC) PACKAGE (TOP VIEW) CATHODE ANODE ANODE NC 1 8 2 7 3 6 4 5 TL431, TL431A, TL431B . . . P (PDIP), PS (SOP), OR PW (TSSOP) PACKAGE (TOP VIEW) REF ANODE ANODE NC CATHODE NC NC NC NC − No internal connection 1 8 2 7 3 6 4 5 REF NC ANODE NC NC − No internal connection TL431, TL431A, TL431B . . . PK (SOT-89) PACKAGE (TOP VIEW) TL432, TL432A, TL432B . . . PK (SOT-89) PACKAGE (TOP VIEW) REF ANODE ANODE CATHODE ANODE ANODE REF CATHODE TL432, TL432A, TL432B . . . DBV (SOT-23-5) PACKAGE (TOP VIEW) TL431, TL431A, TL431B . . . DBV (SOT-23-5) PACKAGE (TOP VIEW) NC 1 † 2 CATHODE 3 5 ANODE 4 REF 2 NC 3 REF 1 CATHODE 2 1 3 5 REF 4 CATHODE TL432, TL432A, TL432B . . . DBZ (SOT-23-3) PACKAGE (TOP VIEW) TL431, TL431A, TL431B . . . DBZ (SOT-23-3) PACKAGE (TOP VIEW) REF 1 NC − No internal connection NC − No internal connection † Pin 2 is attached to Substrate and must be connected to ANODE or left open. CATHODE NC ANODE ANODE 3 2 ANODE Table 6-1. Pin Functions PIN TL431x NAME 4 TL432x TYPE DESCRIPTION DBZ DBV PK D P, PS PW CATHODE 1 3 3 1 1 1 1 1 2 4 1 I/O REF 2 4 1 8 8 3 3 3 1 5 3 I Threshold relative to common anode ANODE 3 5 2 2, 3, 6, 7 6 2 2 6 3 2 2 O Common pin, normally connected to ground LP KTP DCK DBZ DBV PK Submit Document Feedback Shunt Current/Voltage input Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 7 Specifications 7.1 Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted)(1) MIN VKA Cathode voltage(2) IKA Continuous cathode current range II(ref) Reference input current range TJ Operating virtual junction temperature Tstg Storage temperature range (1) (2) MAX UNIT 37 V –100 150 mA –0.05 10 mA 150 °C 150 °C –65 Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. All voltage values are with respect to ANODE, unless otherwise noted. 7.2 ESD Ratings VALUE V(ESD) (1) (2) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 Charged-device model (CDM), per JEDEC specification JESD22C101(2) ±1000 UNIT V JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. Manufacturing with less than 500-V HBM is possible with the necessary precautions. JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. Manufacturing with less than 250-V CDM is possible with the necessary precautions. 7.3 Thermal Information TL43xx THERMAL METRIC(1) P PW D PS 8 PINS DCK DBV 6 PINS 5 PINS DBZ LP PK RθJA Junction-to-ambient thermal resistance 85 149 97 95 259 206 206 140 52 RθJC(top) Junction-to-case (top) thermal resistance 57 65 39 46 87 131 76 55 9 (1) UNIT 3 PINS °C/W For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report (SPRA953). 7.4 Recommended Operating Conditions See(1) VKA Cathode voltage IKA Cathode current MIN MAX Vref 36 V 1 100 mA 0 70 TL43xxI –40 85 TL43xxQ –40 125 TL43xxC TA (1) Operating free-air temperature UNIT °C Maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any allowable ambient temperature is PD = (TJ(max) – TA)/θJA. Operating at the absolute maximum TJ of 150°C can affect reliability. Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 5 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 7.5 Electrical Characteristics, TL431C, TL432C over recommended operating conditions, TA = 25°C (unless otherwise noted) PARAMETER TEST CIRCUIT MIN TYP MAX 2440 2495 2550 SOT23-3 and TL432 devices 6 16 All other devices 4 25 –1.4 –2.7 –1 –2 UNIT Vref Reference voltage See Figure 8-1 VKA = Vref, IKA = 10 mA VI(dev) Deviation of reference input voltage over full temperature range(1) See Figure 8-1 ΔVref / ΔVKA Ratio of change in reference voltage to the change in cathode voltage See Figure 8-2 IKA = 10 mA Iref Reference input current See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 2 4 µA II(dev) Deviation of reference input current over full temperature range(1) See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 0.4 1.2 µA Imin Minimum cathode current for regulation See Figure 8-1 VKA = Vref 0.4 1 mA Ioff Off-state cathode current See Figure 8-3 VKA = 36 V, Vref = 0 0.1 1 µA Dynamic impedance(2) VKA = Vref, f ≤ 1 kHz, See Figure 8-1 IKA = 1 mA to 100 mA 0.2 0.5 Ω |zKA| (1) (2) VKA = Vref, IKA = 10 mA, ΔVKA = 10 V – Vref ΔVKA = 36 V – 10 V mV mV mV/V The deviation parameters Vref(dev) and Iref(dev) are defined as the differences between the maximum and minimum values obtained over the rated temperature range. The average full-range temperature coefficient of the reference input voltage αVref is defined as: αVref is positive or negative, depending on whether minimum Vref or maximum Vref, respectively, occurs at the lower temperature. ∆VKA |zKA| = ∆IKA The dynamic impedance is defined as: When the device is operating with two external resistors (see Figure 8-2), the total dynamic impedance of the circuit is given by: |z'| = ∆V |z | 1 + R1 R2 . ∆I which is approximately equal to KA ( 6 TL431C, TL432C TEST CONDITIONS ( Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 7.6 Electrical Characteristics, TL431I, TL432I over recommended operating conditions, TA = 25°C (unless otherwise noted) PARAMETER TEST CIRCUIT TEST CONDITIONS TL431I, TL432I MIN TYP MAX 2440 2495 2550 14 34 5 50 –1.4 –2.7 –1 –2 UNIT Vref Reference voltage See Figure 8-1 VKA = Vref, IKA = 10 mA VI(dev) Deviation of reference input voltage over full temperature range(1) See Figure 8-1 ΔVref / ΔVKA Ratio of change in reference voltage to the change in cathode voltage See Figure 8-2 IKA = 10 mA Iref Reference input current See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 2 4 µA II(dev) Deviation of reference input current over full temperature range(1) See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 0.8 2.5 µA Imin Minimum cathode current for regulation See Figure 8-1 VKA = Vref 0.4 1 mA Ioff Off-state cathode current See Figure 8-3 VKA = 36 V, Vref = 0 0.1 1 µA Dynamic impedance(2) VKA = Vref, f ≤ 1 kHz, See Figure 8-1 IKA = 1 mA to 100 mA 0.2 0.5 Ω |zKA| VKA = Vref, IKA = 10 mA SOT23-3 and TL432 devices All other devices ΔVKA = 10 V – Vref ΔVKA = 36 V – 10 V mV mV mV/V Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 7 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 7.7 Electrical Characteristics, TL431Q, TL432Q over recommended operating conditions, TA = 25°C (unless otherwise noted) PARAMETER TL431Q, TL432Q TEST CONDITIONS UNIT MIN TYP MAX 2440 2495 2550 mV 14 34 mV –1.4 –2.7 –1 –2 Vref Reference voltage See Figure 8-1 VKA = Vref, IKA = 10 mA VI(dev) Deviation of reference input voltage over full temperature range(1) See Figure 8-1 VKA = Vref, IKA = 10 mA ΔVref / ΔVKA Ratio of change in reference voltage to the change in cathode voltage See Figure 8-2 IKA = 10 mA Iref Reference input current See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 2 4 µA II(dev) Deviation of reference input current over full temperature range(1) See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 0.8 2.5 µA Imin Minimum cathode current for regulation See Figure 8-1 VKA = Vref 0.4 1 mA Ioff Off-state cathode current See Figure 8-3 VKA = 36 V, Vref = 0 0.1 1 µA Dynamic impedance(2) VKA = Vref, f ≤ 1 kHz, See Figure 8-1 IKA = 1 mA to 100 mA 0.2 0.5 Ω |zKA| 8 TEST CIRCUIT ΔVKA = 10 V – Vref ΔVKA = 36 V – 10 V Submit Document Feedback mV/V Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 7.8 Electrical Characteristics, TL431AC, TL432AC over recommended operating conditions, TA = 25°C (unless otherwise noted) PARAMETER TEST CIRCUIT TEST CONDITIONS TL431AC, TL432AC MIN TYP MAX 2470 2495 2520 SOT23-3 and TL432 devices 6 16 All other devices 4 25 –1.4 –2.7 –1 –2 UNIT Vref Reference voltage See Figure 8-1 VKA = Vref, IKA = 10 mA VI(dev) Deviation of reference input voltage over full temperature range(1) See Figure 8-1 ΔVref / ΔVKA Ratio of change in reference voltage to the change in cathode voltage See Figure 8-2 IKA = 10 mA Iref Reference input current See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 2 4 µA II(dev) Deviation of reference input current over full temperature range(1) See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 0.8 1.2 µA Imin Minimum cathode current for regulation See Figure 8-1 VKA = Vref 0.4 0.6 mA Ioff Off-state cathode current See Figure 8-3 VKA = 36 V, Vref = 0 0.1 0.5 µA Dynamic impedance(2) VKA = Vref, f ≤ 1 kHz, See Figure 8-1 IKA = 1 mA to 100 mA 0.2 0.5 Ω |zKA| VKA = Vref, IKA = 10 mA ΔVKA = 10 V – Vref ΔVKA = 36 V – 10 V mV mV mV/V Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 9 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 7.9 Electrical Characteristics, TL431AI, TL432AI over recommended operating conditions, TA = 25°C (unless otherwise noted) PARAMETER TEST CIRCUIT TL431AI, TL432AI TEST CONDITIONS MIN TYP MAX 2470 2495 2520 14 34 5 50 –1.4 –2.7 –1 –2 UNIT Vref Reference voltage See Figure 8-1 VKA = Vref, IKA = 10 mA VI(dev) Deviation of reference input voltage over full temperature range(1) See Figure 8-1 ΔVref / ΔVKA Ratio of change in reference voltage to the change in cathode voltage See Figure 8-2 IKA = 10 mA Iref Reference input current See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 2 4 µA II(dev) Deviation of reference input current over full temperature range(1) See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 0.8 2.5 µA Imin Minimum cathode current for regulation See Figure 8-1 VKA = Vref 0.4 0.7 mA Ioff Off-state cathode current See Figure 8-3 VKA = 36 V, Vref = 0 0.1 0.5 µA Dynamic impedance(2) VKA = Vref, f ≤ 1 kHz, See Figure 8-1 IKA = 1 mA to 100 mA 0.2 0.5 Ω |zKA| 10 VKA = Vref, IKA = 10 mA SOT23-3 and TL432 devices All other devices ΔVKA = 10 V – Vref ΔVKA = 36 V – 10 V Submit Document Feedback mV mV mV/V Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 7.10 Electrical Characteristics, TL431AQ, TL432AQ over recommended operating conditions, TA = 25°C (unless otherwise noted) PARAMETER TEST CIRCUIT TEST CONDITIONS TL431AQ, TL432AQ UNIT MIN TYP MAX 2470 2495 2520 mV 14 34 mV –1.4 –2.7 –1 –2 Vref Reference voltage See Figure 8-1 VKA = Vref, IKA = 10 mA VI(dev) Deviation of reference input voltage over full temperature range(1) See Figure 8-1 VKA = Vref, IKA = 10 mA ΔVref / ΔVKA Ratio of change in reference voltage to the change in cathode voltage See Figure 8-2 IKA = 10 mA Iref Reference input current See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 2 4 µA II(dev) Deviation of reference input current over full temperature range(1) See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 0.8 2.5 µA Imin Minimum cathode current for regulation See Figure 8-1 VKA = Vref 0.4 0.7 mA Ioff Off-state cathode current See Figure 8-3 VKA = 36 V, Vref = 0 0.1 0.5 µA Dynamic impedance(2) VKA = Vref, f ≤ 1 kHz, See Figure 8-1 IKA = 1 mA to 100 mA 0.2 0.5 Ω |zKA| ΔVKA = 10 V – Vref ΔVKA = 36 V – 10 V mV/V Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 11 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 7.11 Electrical Characteristics, TL431BC, TL432BC over recommended operating conditions, TA = 25°C (unless otherwise noted) PARAMETER TEST CIRCUIT TL431BC, TL432BC TEST CONDITIONS UNIT MIN TYP MAX 2483 2495 2507 mV 6 16 mV –1.4 –2.7 – –2 Vref Reference voltage See Figure 8-1 VKA = Vref, IKA = 10 mA VI(dev) Deviation of reference input voltage over full temperature range(1) See Figure 8-1 VKA = Vref, IKA = 10 mA ΔVref / ΔVKA Ratio of change in reference voltage to the change in cathode voltage See Figure 8-2 IKA = 10 mA Iref Reference input current See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 2 4 µA II(dev) Deviation of reference input current over full temperature range(1) See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 0.8 1.2 µA Imin Minimum cathode current for regulation See Figure 8-1 VKA = Vref 0.4 0.6 mA Ioff Off-state cathode current See Figure 8-3 VKA = 36 V, Vref = 0 0.1 0.5 µA Dynamic impedance(2) VKA = Vref, f ≤ 1 kHz, See Figure 8-1 IKA = 1 mA to 100 mA 0.2 0.5 Ω |zKA| 12 ΔVKA = 10 V – Vref ΔVKA = 36 V – 10 V Submit Document Feedback mV/V Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 7.12 Electrical Characteristics, TL431BI, TL432BI over recommended operating conditions, TA = 25°C (unless otherwise noted) PARAMETER TEST CIRCUIT TEST CONDITIONS TL431BI, TL432BI UNIT MIN TYP MAX 2483 2495 2507 mV 14 34 mV –1.4 –2.7 –1 –2 Vref Reference voltage See Figure 8-1 VKA = Vref, IKA = 10 mA VI(dev) Deviation of reference input voltage over full temperature range(1) See Figure 8-1 VKA = Vref, IKA = 10 mA ΔVref / ΔVKA Ratio of change in reference voltage to the change in cathode voltage See Figure 8-2 IKA = 10 mA Iref Reference input current See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 2 4 µA II(dev) Deviation of reference input current over full temperature range(1) See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 0.8 2.5 µA Imin Minimum cathode current for regulation See Figure 8-1 VKA = Vref 0.4 0.7 mA Ioff Off-state cathode current See Figure 8-3 VKA = 36 V, Vref = 0 0.1 0.5 µA Dynamic impedance(2) VKA = Vref, f ≤ 1 kHz, See Figure 8-1 IKA = 1 mA to 100 mA 0.2 0.5 Ω |zKA| ΔVKA = 10 V – Vref ΔVKA = 36 V – 10 V mV/V Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 13 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 7.13 Electrical Characteristics, TL431BQ, TL432BQ over recommended operating conditions, TA = 25°C (unless otherwise noted) PARAMETER TEST CIRCUIT TL431BQ, TL432BQ TEST CONDITIONS UNIT MIN TYP MAX 2483 2495 2507 mV 14 34 mV –1.4 –2.7 –1 –2 Vref Reference voltage See Figure 8-1 VKA = Vref, IKA = 10 mA VI(dev) Deviation of reference input voltage over full temperature range(1) See Figure 8-1 VKA = Vref, IKA = 10 mA ΔVref / ΔVKA Ratio of change in reference voltage to the change in cathode voltage See Figure 8-2 IKA = 10 mA Iref Reference input current See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 2 4 µA II(dev) Deviation of reference input current over full temperature range(1) See Figure 8-2 IKA = 10 mA, R1 = 10 kΩ, R2 = ∞ 0.8 2.5 µA Imin Minimum cathode current for regulation See Figure 8-1 VKA = Vref 0.4 0.7 mA Ioff Off-state cathode current See Figure 8-3 VKA = 36 V, Vref = 0 0.1 0.5 µA Dynamic impedance(2) VKA = Vref, f ≤ 1 kHz, See Figure 8-1 IKA = 1 mA to 100 mA 0.2 0.5 Ω |zKA| 14 ΔVKA = 10 V – Vref ΔVKA = 36 V – 10 V Submit Document Feedback mV/V Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 Typical Characteristics Data at high and low temperatures are applicable only within the recommended operating free-air temperature ranges of the various devices. 2600 5 Vref = 2550 mV 2560 4 I ref − Reference Current − µA V ref − Reference Voltage − mV R1 = 10 kΩ R2 =∞ IKA = 10 mA VKA = Vref IKA = 10 mA 2580 2540 2520 Vref = 2495 mV 2500 2480 2460 Vref = 2440 mV 2440 3 2 1 2420 2400 −75 −50 −25 0 25 50 75 100 0 −75 125 −50 Figure 7-1. Reference Voltage vs Free-Air Temperature 25 0 50 75 100 125 Figure 7-2. Reference Current vs Free-Air Temperature 800 150 VKA = Vref TA = 25°C 125 VKA = Vref TA = 25°C 600 I KA − Cathode Current − µ A 100 I KA − Cathode Current − mA −25 TA − Free-Air Temperature − °C TA − Free-Air Temperature − °C 75 50 25 0 −25 −50 Imin 400 200 0 −75 −100 −2 −1 0 2 1 −200 −1 3 0 VKA − Cathode Voltage − V 1 Figure 7-3. Cathode Current vs Cathode Voltage 3 Figure 7-4. Cathode Current vs Cathode Voltage − 0.85 2.5 VKA = 36 V Vref = 0 VKA = 3 V to 36 V − 0.95 2 ∆V ref / ∆V KA − mV/V I off − Off-State Cathode Current − µA 2 VKA − Cathode Voltage − V 1.5 1 0.5 −1.05 −1.15 −1.25 −1.35 16 0 −75 16 −50 −25 0 25 50 75 100 125 −1.45 −75 TA − Free-Air Temperature − °C −50 −25 0 25 50 75 100 125 TA − Free-Air Temperature − °C Figure 7-5. Off-State Cathode Current vs Free-Air Temperature Figure 7-6. Ratio of Delta Reference Voltage to Delta Cathode Voltage vs Free-Air Temperature Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 15 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 Typical Characteristics Data at high and low temperatures are applicable only within the recommended operating free-air temperature ranges of the various devices. 6 IO = 10 mA TA = 25°C 240 V n − Equivalent Input Noise V oltage − µV Vn − Equivalent Input Noise V oltage − nV/ Hz 260 220 200 180 160 140 120 16 100 10 100 1k 10 k 5 4 3 2 1 0 −1 −2 −3 f = 0.1 to 10 Hz IKA = 10 mA TA = 25°C −4 −5 −6 100 k 0 1 2 3 f − Frequency − Hz 4 5 6 7 8 9 10 t − Time − s Figure 7-7. Equivalent Input Noise Voltage vs Frequency Figure 7-8. Equivalent Input Noise Voltage Over a 10-S Period 19.1 V 1 kΩ 500 µF 910 Ω 2000 µF VCC TL431 (DUT) + VCC 1 µF TLE2027 AV = 10 V/mV 820 Ω + − 16 kΩ 16 kΩ 1 µF 22 µF − 16 Ω 160 kΩ TLE2027 To Oscilloscope 33 kΩ AV = 2 V/V 0.1 µF 33 kΩ VEE VEE Figure 7-9. Test Circuit for Equivalent Input Noise Voltage Over a 10-S Period 16 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 Typical Characteristics Data at high and low temperatures are applicable only within the recommended operating free-air temperature ranges of the various devices. IKA = 10 mA TA = 25°C A V − Small-Signal V oltage Amplification − dB 60 IKA = 10 mA TA = 25°C 50 Output 40 IKA 15 kΩ 232 Ω 30 9 µF + 20 − 8.25 kΩ 10 GND 0 1k 10 k 100 k 1M 10 M f − Frequency − Hz Figure 7-10. Small-Signal Voltage Amplification vs Frequency Figure 7-11. Test Circuit for Voltage Amplification |z KA| − Reference Impedance − Ω 100 1 kΩ Output IKA = 10 mA TA = 25°C IKA 50 Ω 10 − + GND 1 Figure 7-13. Test Circuit for Reference Impedance 0.1 1k 10 k 100 k 1M 10 M f − Frequency − Hz Figure 7-12. Reference Impedance vs Frequency 6 220 Ω TA = 25°C Output Input Input and Output V oltage − V 5 Pulse Generator f = 100 kHz 4 3 Output GND 2 Figure 7-15. Test Circuit for Pulse Response 1 0 −1 50 Ω 0 1 2 3 4 5 6 7 t − Time − µs Figure 7-14. Pulse Response Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 17 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 Typical Characteristics Data at high and low temperatures are applicable only within the recommended operating free-air temperature ranges of the various devices. 100 90 I KA − Cathode Current − mA 80 A V KA B V KA C VKA D VKA 150 Ω = Vref =5V = 10 V = 15 Vf TA = 25°C IKA + B VBATT CL 70 − Stable 60 C Stable 50 A 40 TEST CIRCUIT FOR CURVE A 30 D 20 IKA 10 R1 = 10 kΩ 0 0.001 0.01 0.1 10 1 150 Ω CL CL − Load Capacitance − µF + The areas under the curves represent conditions that may cause the device to oscillate. For curves B, C, and D, R2 and V+ are adjusted to establish the initial VKA and IKA conditions, with CL = 0. VBATT and CL then are adjusted to determine the ranges of stability. R2 VBATT − TEST CIRCUIT FOR CURVES B, C, AND D Figure 7-17. Test Circuits for Stability Boundary Conditions Figure 7-16. Stability Boundary Conditions for All TL431 and TL431A Devices (Except for SOT23-3, SC-70, and Q-Temp Devices) 100 90 I KA − Cathode Current − mA 80 A VKA B V KA C VKA D VKA 150 Ω = Vref =5V = 10 V = 15 Vf IKA + 70 VBATT CL B − TA = 25°C 60 C Stable Stable 50 A TEST CIRCUIT FOR CURVE A 40 A 30 D IKA 20 R1 = 10 kΩ B 150 Ω 10 0 0.001 CL 0.01 0.1 1 + 10 R2 CL − Load Capacitance − µF VBATT − The areas under the curves represent conditions that may cause the device to oscillate. For curves B, C, and D, R2 and V+ are adjusted to establish the initial VKA and IKA conditions, with CL = 0. VBATT and CL then are adjusted to determine the ranges of stability. TEST CIRCUIT FOR CURVES B, C, AND D Figure 7-19. Test Circuit for Stability Boundary Conditions Figure 7-18. Stability Boundary Conditions for All TL431B, TL432, SOT-23, SC-70, and Q-Temp Devices 18 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 8 Parameter Measurement Information VKA Input IKA Vref Figure 8-1. Test Circuit for VKA = Vref Input VKA IKA R1 Iref R2 Vref R1 ö æ VKA = Vref ç 1 + ÷ + Iref × R1 R2 ø è Figure 8-2. Test Circuit for VKA > Vref Input VKA Ioff Figure 8-3. Test Circuit for Ioff Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 19 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 9 Detailed Description 9.1 Overview This standard device has proven ubiquity and versatility across a wide range of applications, ranging from power to signal path. This is due to it's key components containing an accurate voltage reference & opamp, which are very fundamental analog building blocks. TL43xx is used in conjunction with it's key components to behave as a single voltage reference, error amplifier, voltage clamp or comparator with integrated reference. TL43xx can be operated and adjusted to cathode voltages from 2.5V to 36V, making this part optimum for a wide range of end equipments in industrial, auto, telecom & computing. In order for this device to behave as a shunt regulator or error amplifier, >1mA (Imin(max)) must be supplied in to the cathode pin. Under this condition, feedback can be applied from the Cathode and Ref pins to create a replica of the internal reference voltage. Various reference voltage options can be purchased with initial tolerances (at 25°C) of 0.5%, 1%, and 2%. These reference options are denoted by B (0.5%), A (1.0%) and blank (2.0%) after the TL431 or TL432. TL431 & TL432 are both functionaly, but have separate pinout options. The TL43xxC devices are characterized for operation from 0°C to 70°C, the TL43xxI devices are characterized for operation from –40°C to 85°C, and the TL43xxQ devices are characterized for operation from –40°C to 125°C. 9.2 Functional Block Diagram CATHODE + REF _ Vref ANODE Figure 9-1. Equivalent Schematic CATHODE 800 Ω 800 Ω 20 pF REF 150 Ω 3.28 kΩ 2.4 kΩ 7.2 kΩ 4 kΩ 10 kΩ 20 pF 1 kΩ 800 Ω ANODE Figure 9-2. Detailed Schematic 20 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 9.3 Feature Description TL43xx consists of an internal reference and amplifier that outputs a sink current base on the difference between the reference pin and the virtual internal pin. The sink current is produced by the internal Darlington pair, shown in the above schematic (Figure 9-2). A Darlington pair is used in order for this device to be able to sink a maximum current of 100 mA. When operated with enough voltage headroom (≥ 2.5 V) and cathode current (IKA), TL431 forces the reference pin to 2.5 V. However, the reference pin can not be left floating, as it needs IREF ≥ 4 µA (please see Electrical Characteristics, TL431C, TL432C). This is because the reference pin is driven into an npn, which needs base current in order operate properly. When feedback is applied from the Cathode and Reference pins, TL43xx behaves as a Zener diode, regulating to a constant voltage dependent on current being supplied into the cathode. This is due to the internal amplifier and reference entering the proper operating regions. The same amount of current needed in the above feedback situation must be applied to this device in open loop, servo or error amplifying implementations in order for it to be in the proper linear region giving TL43xx enough gain. Unlike many linear regulators, TL43xx is internally compensated to be stable without an output capacitor between the cathode and anode. However, if it is desired to use an output capacitor Figure 9-2 can be used as a guide to assist in choosing the correct capacitor to maintain stability. 9.4 Device Functional Modes 9.4.1 Open Loop (Comparator) When the cathode/output voltage or current of TL43xx is not being fed back to the reference/input pin in any form, this device is operating in open loop. With proper cathode current (Ika) applied to this device, TL43xx will have the characteristics shown in Figure 9-1. With such high gain in this configuration, TL43xx is typically used as a comparator. With the reference integrated makes TL43xx the prefered choice when users are trying to monitor a certain level of a single signal. 9.4.2 Closed Loop When the cathode/output voltage or current of TL43xx is being fed back to the reference/input pin in any form, this device is operating in closed loop. The majority of applications involving TL43xx use it in this manner to regulate a fixed voltage or current. The feedback enables this device to behave as an error amplifier, computing a portion of the output voltage and adjusting it to maintain the desired regulation. This is done by relating the output voltage back to the reference pin in a manner to make it equal to the internal reference voltage, which can be accomplished via resistive or direct feedback. Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 21 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 10 Applications and Implementation Note Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 10.1 Application Information As this device has many applications and setups, there are many situations that this datasheet can not characterize in detail. The linked application notes will help the designer make the best choices when using this part. Application note Understanding Stability Boundary Conditions Charts in TL431, TL432 Data Sheet (SLVA482) will provide a deeper understanding of this devices stability characteristics and aid the user in making the right choices when choosing a load capacitor. Application note Setting the Shunt Voltage on an Adjustable Shunt Regulator (SLVA445) assists designers in setting the shunt voltage to achieve optimum accuracy for this device. 10.2 Typical Applications 10.2.1 Comparator With Integrated Reference Vsup Rsup Vout CATHODE R1 VIN RIN REF VL + R2 2.5V ANODE Figure 10-1. Comparator Application Schematic 22 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: TL431 TL432 TL431, TL432 www.ti.com SLVS543Q – AUGUST 2004 – REVISED JULY 2022 10.2.1.1 Design Requirements For this design example, use the parameters listed in Table 10-1 as the input parameters. Table 10-1. Design Parameters DESIGN PARAMETER EXAMPLE VALUE Input Voltage Range 0 V to 5 V Input Resistance 10 kΩ Supply Voltage 24 V Cathode Current (Ik) 5 mA Output Voltage Level ~2 V – VSUP Logic Input Thresholds VIH/VIL VL 10.2.1.2 Detailed Design Procedure When using TL431 as a comparator with reference, determine the following: • • • • Input Voltage Range Reference Voltage Accuracy Output logic input high and low level thresholds Current Source resistance 10.2.1.2.1 Basic Operation In the configuration shown in Figure 10-1 TL431 will behave as a comparator, comparing the VREF pin voltage to the internal virtual reference voltage. When provided a proper cathode current (IK), TL43xx will have enough open loop gain to provide a quick response. This can be seen in Figure 10-2, where the RSUP=10 kΩ (IKA=500 µA) situation responds much slower than RSUP=1 kΩ (IKA=5 mA). With the TL43xx's max Operating Current (IMIN) being 1 mA, operation below that could result in low gain, leading to a slow response. 10.2.1.2.1.1 Overdrive Slow or inaccurate responses can also occur when the reference pin is not provided enough overdrive voltage. This is the amount of voltage that is higher than the internal virtual reference. The internal virtual reference voltage will be within the range of 2.5 V ±(0.5%, 1.0% or 1.5%) depending on which version is being used. The more overdrive voltage provided, the faster the TL431 will respond. For applications where TL431 is being used as a comparator, it is best to set the trip point to greater than the positive expected error (i.e. +1.0% for the A version). For fast response, setting the trip point to >10% of the internal VREF should suffice. For minimal voltage drop or difference from Vin to the ref pin, it is recommended to use an input resistor