Texas Instruments TL431 datasheet

TL431, TL432 Precision Programmable Reference

1 Features

• Reference voltage tolerance at 25°C
  • 0.5% (B grade)
  • 1% (A grade)
  • 2% (Standard grade)
• Adjustable output voltage: V_ref to 36V
• Operation from –40°C to 125°C
• Typical temperature drift (TL43xB)
  • 6mV (C temp)
  • 14mV (I temp, Q temp)
• Low Output Noise
• 0.2Ω Typical output impedance
• Sink-current capability: 1mA to 100mA

2 Applications

• Rack server power
• Industrial AC/DC
• AC inverter & VF drives
• Servo drive control module
• Notebook PC power adapter design

3 Description

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 V_ref (approximately 2.5V) and 36V, with two external resistors. These devices have a typical output impedance of 0.2Ω. Active output circuitry provides a very sharp turn-on characteristic, making these devices excellent replacements for Zener diodes in many applications, such as on-board 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 verifies 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

(1) For all available packages, see the orderable addendum at the end of the data sheet.

(2) The package size (length × width) is a nominal value and includes pins, where applicable.

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
SLVS543S – AUGUST 2004 – REVISED MAY 2024

Table of Contents

• 1 Features ........ 1
• 2 Applications ........ 1
• 3 Description ........ 1
• 4 Device Comparison Table ........ 3
• 5 Pin Configuration and Functions ........ 4
• 6 Specifications ........ 5
• 6.1 Absolute Maximum Ratings ........ 5
• 6.2 ESD Ratings ........ 5
• 6.3 Thermal Information ........ 5
• 6.4 Recommended Operating Conditions ........ 5
• 6.5 Electrical Characteristics, TL431C, TL432C ........ 6
• 6.6 Electrical Characteristics, TL431I, TL432I ........ 7
• 6.7 Electrical Characteristics, TL431Q, TL432Q ........ 8
• 6.8 Electrical Characteristics, TL431AC, TL432AC ........ 9
• 6.9 Electrical Characteristics, TL431AI, TL432AI ........ 10
• 6.10 Electrical Characteristics, TL431AQ, TL432AQ ........ 11
• 6.11 Electrical Characteristics, TL431BC, TL432BC ........ 12
• 6.12 Electrical Characteristics, TL431BI, TL432BI ........ 13
• 6.13 Electrical Characteristics, TL431BQ, TL432BQ ........ 14
• 6.14 Typical Characteristics ........ 15
• 7 Parameter Measurement Information ........ 19
• 7.1 Temperature Coefficient ........ 19
• 7.2 Dynamic Impedance ........ 20
• 8 Detailed Description ........ 21
• 8.1 Overview ........ 21
• 8.2 Functional Block Diagram ........ 21
• 8.3 Feature Description ........ 22
• 8.4 Device Functional Modes ........ 22
• 9 Applications and Implementation ........ 23
• 9.1 Application Information ........ 23
• 9.2 Typical Applications ........ 23
• 9.3 System Examples ........ 28
• 9.4 Power Supply Recommendations ........ 31
• 9.5 Layout ........ 31
• 10 Device and Documentation Support ........ 32
• 10.1 Device Nomenclature ........ 32
• 10.2 Related Links ........ 32
• 10.3 Receiving Notification of Documentation Updates ........ 32
• 10.4 Support Resources ........ 32
• 10.5 Trademarks ........ 32
• 10.6 Electrostatic Discharge Caution ........ 33
• 10.7 Glossary ........ 33
• 11 Revision History ........ 33
• 12 Mechanical, Packaging, and Orderable Information ........ 33

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4 Device Comparison Table

5 Pin Configuration and Functions

TL431, TL431A, TL431B ... LP (TO-92/TO-226) PACKAGE (TOP VIEW)

TL431A, TL431B ... DCK (SC-70) PACKAGE (TOP VIEW)

NC – No internal connection

• • Must be connected to ANODE or left open

TL431, TL431A, TL431B ... D (SOIC) PACKAGE (TOP VIEW)

NC – No internal connection

TL431, TL431A, TL431B ... P (PDIP), PS (SOP), OR PW (TSSOP) PACKAGE (TOP VIEW)

NC – No internal connection

TL431, TL431A, TL431B ... PK (SOT-89) PACKAGE (TOP VIEW)

TL432, TL432A, TL432B ... PK (SOT-89) PACKAGE (TOP VIEW)

TL431, TL431A, TL431B ... DBV (SOT-23-5) PACKAGE (TOP VIEW)

NC – No internal connection
† Pin 2 is attached to Substrate and must be connected to ANODE or left open.

TL432, TL432A, TL432B ... DBV (SOT-23-5) PACKAGE (TOP VIEW)

NC – No internal connection

TL431, TL431A, TL431B ... DBZ (SOT-23-3) PACKAGE (TOP VIEW)

TL432, TL432A, TL432B ... DBZ (SOT-23-3) PACKAGE (TOP VIEW)

Table 5-1. Pin Functions

6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)⁽¹⁾

(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

(2) All voltage values are with respect to ANODE, unless otherwise noted.

6.2 ESD Ratings

(1) JEDEC document JEP155 states that 500V HBM allows safe manufacturing with a standard ESD control process. Manufacturing with less than 500V HBM is possible with the necessary precautions.

(2) JEDEC document JEP157 states that 250V CDM allows safe manufacturing with a standard ESD control process. Manufacturing with less than 250V CDM is possible with the necessary precautions.

6.3 Thermal Information

(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report (SPRA953)

6.4 Recommended Operating Conditions

See ⁽¹⁾

(1) 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.

TL431, TL432

SLVS543S – AUGUST 2004 – REVISED MAY 2024

6.5 Electrical Characteristics, TL431C, TL432C

over recommended operating conditions, T$_A$ = 25°C (unless otherwise noted)

\begin{tabular}{|l|l|l|l|r|r|r|l|} \hline \multicolumn{2}{|c|}{\textbf{PARAMETER}} & \textbf{TEST CIRCUIT} & \textbf{TEST CONDITIONS} & \textbf{MIN} & \textbf{TYP} & \textbf{MAX} & \textbf{UNIT} \ \hline V_ref & Reference Voltage & See Figure 7-1 & V_KA = V_ref, I_KA = 10mA & 2440 & 2495 & 2550 & mV \ \hline \multirow{2}{}{V_I(dev)} & \multirow{2}{}{Deviation of reference input voltage over full temperature range $^{(1)} & \multirow2See Figure 7-1 & \multirow2V_{\text{KA}}$ = V_ref, I_KA = 10mA} & SOT23-3 and TL432 devices & 6 & 16 & mV \ \cline{5-8} & & & & All other devices & 4 & 25 & mV \ \hline \multirow{2}{}{\DeltaV_ref / \DeltaV_KA} & \multirow{2}{}{Ratio of change in reference voltage to the change in cathode voltage} & \multirow{2}{}{See Figure 7-2} & \multirow{2}{}{I_KA = 10mA} & \DeltaV_KA = 10V- V_ref & -1.4 & -2.7 & mV/V \ \cline{5-8} & & & & \DeltaV_KA = 36V- 10V & -1 & -2 & mV/V \ \hline I_ref & Reference Input Current & See Figure 7-2 & I_KA = 10mA, R1 = 10k\Omega, R2 = \infty & & 2 & 4 & \muA \ \hline I_I(dev) & Deviation of reference input current over full temperature range $^{(1)}$ & See Figure 7-2 & I_KA = 10mA, R1 = 10k\Omega, R2 = \infty & & 0.4 & 1.2 & \muA \ \hline I_min & Minimum cathode current for regulation & See Figure 7-1 & V_KA = V_ref & & 0.4 & 1 & mA \ \hline I_off & Off-state cathode current & See Figure 7-3 & V_KA = 36V, V_ref = 0 & & 0.1 & 1 & \muA \ \hline |Z_KA| & Dynamic Impedance $^{(2)}$ & See Figure 7-1 & V_KA = V_ref, f \leq 1kHz, I_KA = 1mA to 100mA & & 0.2 & 0.5 & \Omega \ \hline \end{tabular}

(1) The deviation parameters V_I(dev) and I_I(dev) are defined as the differences between the maximum and minimum values obtained over the rated temperature range. For more details on V_I(dev) and how it relates to the average temperature coefficient, see Temperature Coefficient. (2) The dynamic impedance is defined by |Z_KA| = \DeltaV_KA/\DeltaI_KA. For more details on |Z_KA| and how it relates to V_KA, see Dynamic Impedance.

6.6 Electrical Characteristics, TL431I, TL432I

over recommended operating conditions, TA = 25°C (unless otherwise noted)

(1) The deviation parameters VI(dev) and II(dev) are defined as the differences between the maximum and minimum values obtained over the rated temperature range. For more details on VI(dev) and how it relates to the average temperature coefficient, see Temperature Coefficient.

(2) The dynamic impedance is defined by |ZKA| = ΔVKA/ΔIKA. For more details on |ZKA| and how it relates to VKA, see Dynamic Impedance.

TL431, TL432

SLVS543S – AUGUST 2004 – REVISED MAY 2024

6.7 Electrical Characteristics, TL431Q, TL432Q

over recommended operating conditions, T$_{A}$ = 25°C (unless otherwise noted)

\begin{tabular}{|l|l|l|l|r|r|r|l|} \hline \multicolumn{2}{|c|}{PARAMETER} & TEST CIRCUIT & TEST CONDITIONS & MIN & TYP & MAX & UNIT \ \hline V_ref & Reference Voltage & See Figure 7-1 & V_KA = V_ref, I_KA = 10mA & 2440 & 2495 & 2550 & mV \ \hline V_I(dev) & Deviation of reference input voltage over full temperature range $^{(1)}$ & See Figure 7-1 & V_KA = V_ref, I_KA = 10mA & & 14 & 34 & mV \ \hline \DeltaV_ref / \DeltaV_KA & Ratio of change in reference voltage to the change in cathode voltage & See Figure 7-2 & I_KA = 10mA & \DeltaV_KA = 10V- V_ref & -1.4 & -2.7 & mV/V \ \cline{4-8} & & & & \DeltaV_KA = 36V- 10V & -1 & -2 & mV/V \ \hline I_ref & Reference Input Current & See Figure 7-2 & I_KA = 10mA, R1 = 10k\Omega, R2 = \infty & & 2 & 4 & \muA \ \hline I_I(dev) & Deviation of reference input current over full temperature range $^{(1)}$ & See Figure 7-2 & I_KA = 10mA, R1 = 10k\Omega, R2 = \infty & & 0.8 & 2.5 & \muA \ \hline I_min & Minimum cathode current for regulation & See Figure 7-1 & V_KA = V_ref & & 0.4 & 1 & mA \ \hline I_off & Off-state cathode current & See Figure 7-3 & V_KA = 36V, V_ref = 0 & & 0.1 & 1 & \muA \ \hline |Z_KA| & Dynamic Impedance $^{(2)}$ & See Figure 7-1 & V_KA = V_ref, f \leq 1kHz, I_KA = 1mA to 100mA & & 0.2 & 0.5 & \Omega \ \hline \end{tabular}

(1) The deviation parameters V_I(dev) and I_I(dev) are defined as the differences between the maximum and minimum values obtained over the rated temperature range. For more details on V_I(dev) and how it relates to the average temperature coefficient, see Temperature Coefficient. (2) The dynamic impedance is defined by |Z_KA| = \DeltaV_KA/\DeltaI_KA. For more details on |Z_KA| and how it relates to V_KA, see Dynamic Impedance.

6.8 Electrical Characteristics, TL431AC, TL432AC

over recommended operating conditions, TA = 25°C (unless otherwise noted)

(1) The deviation parameters VI(dev) and II(dev) are defined as the differences between the maximum and minimum values obtained over the rated temperature range. For more details on VI(dev) and how it relates to the average temperature coefficient, see Temperature Coefficient.

(2) The dynamic impedance is defined by |ZKA| = ΔVKA/ΔIKA. For more details on |ZKA| and how it relates to VKA, see Dynamic Impedance.

6.9 Electrical Characteristics, TL431AI, TL432AI

over recommended operating conditions, TA = 25°C (unless otherwise noted)

(1) The deviation parameters VI(dev) and II(dev) are defined as the differences between the maximum and minimum values obtained over the rated temperature range. For more details on VI(dev) and how it relates to the average temperature coefficient, see Temperature Coefficient.

(2) The dynamic impedance is defined by |ZKA| = ΔVKA/ΔIKA. For more details on |ZKA| and how it relates to VKA, see Dynamic Impedance.

6.10 Electrical Characteristics, TL431AQ, TL432AQ

over recommended operating conditions, TA = 25°C (unless otherwise noted)

(1) The deviation parameters VI(dev) and II(dev) are defined as the differences between the maximum and minimum values obtained over the rated temperature range. For more details on VI(dev) and how it relates to the average temperature coefficient, see Temperature Coefficient.

(2) The dynamic impedance is defined by |ZKA| = ΔVKA/ΔIKA. For more details on |ZKA| and how it relates to VKA, see Dynamic Impedance.

TL431, TL432 SLVS543S – AUGUST 2004 – REVISED MAY 2024

6.11 Electrical Characteristics, TL431BC, TL432BC

over recommended operating conditions, TA = 25°C (unless otherwise noted)

(1) The deviation parameters VI(dev) and II(dev) are defined as the differences between the maximum and minimum values obtained over the rated temperature range. For more details on VI(dev) and how it relates to the average temperature coefficient, see Temperature Coefficient.

(2) The dynamic impedance is defined by |ZKA| = ΔVKA/ΔIKA. For more details on |ZKA| and how it relates to VKA, see Dynamic Impedance.

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6.12 Electrical Characteristics, TL431BI, TL432BI

over recommended operating conditions, TA = 25°C (unless otherwise noted)

(1) The deviation parameters VI(dev) and II(dev) are defined as the differences between the maximum and minimum values obtained over the rated temperature range. For more details on VI(dev) and how it relates to the average temperature coefficient, see Temperature Coefficient.

(2) The dynamic impedance is defined by |ZKA| = ΔVKA/ΔIKA. For more details on |ZKA| and how it relates to VKA, see Dynamic Impedance.

TL431, TL432

SLVS543S – AUGUST 2004 – REVISED MAY 2024

6.13 Electrical Characteristics, TL431BQ, TL432BQ

over recommended operating conditions, $T_A$ = 25°C (unless otherwise noted)

\begin{tabular}{|l|l|l|l|c|c|c|l|} \hline \multicolumn{2}{|c|}{\textbf{PARAMETER}} & \textbf{TEST CIRCUIT} & \textbf{TEST CONDITIONS} & \textbf{MIN} & \textbf{TYP} & \textbf{MAX} & \textbf{UNIT} \ \hline $V_{ref}$ & Reference Voltage & See Figure 7-1 & $V_{KA}$ = $V_{ref}$, $I_{KA}$ = 10mA & 2483 & 2495 & 2507 & mV \ \hline $V_{I(dev)}$ & Deviation of reference input voltage over full temperature range $^{(1)}$ & See Figure 7-1 & $V_{KA}$ = $V_{ref}$, $I_{KA}$ = 10mA & & 14 & 34 & mV \ \hline \Delta V_ref / \Delta V_KA & Ratio of change in reference voltage to the change in cathode voltage & See Figure 7-2 & $I_{KA}$ = 10mA & \Delta V_KA = 10V- $V_{ref}$ & -1.4 & -2.7 & mV/V \ \cline{4-8} & & & & \Delta V_KA = 36V- 10V & -1 & -2 & mV/V \ \hline $I_{ref}$ & Reference Input Current & See Figure 7-2 & $I_{KA}$ = 10mA, R1 = 10k\Omega, R2 = \infty & & 2 & 4 & \muA \ \hline $I_{I(dev)}$ & Deviation of reference input current over full temperature range $^{(1)}$ & See Figure 7-2 & $I_{KA}$ = 10mA, R1 = 10k\Omega, R2 = \infty & & 0.8 & 2.5 & \muA \ \hline $I_{min}$ & Minimum cathode current for regulation & See Figure 7-1 & $V_{KA}$ = $V_{ref}$ & & 0.4 & 0.7 & mA \ \hline $I_{off}$ & Off-state cathode current & See Figure 7-3 & $V_{KA}$ = 36V, $V_{ref}$ = 0 & & 0.1 & 0.5 & \muA \ \hline $|Z_{KA}|$ & Dynamic Impedance $^{(2)}$ & See Figure 7-1 & $V_{KA}$ = $V_{ref}$, f \leq 1kHz, $I_{KA}$ = 1mA to 100mA & & 0.2 & 0.5 & \Omega \ \hline \end{tabular}

(1) The deviation parameters $V_{I(dev)}$ and $I_{I(dev)}$ are defined as the differences between the maximum and minimum values obtained over the rated temperature range. For more details on $V_{I(dev)}$ and how it relates to the average temperature coefficient, see Temperature Coefficient. (2) The dynamic impedance is defined by $|Z_{KA}|$ = \Delta V_KA/\Delta I_KA. For more details on $|Z_{KA}|$ and how it relates to $V_{KA}$, see Dynamic Impedance.

6.14 Typical Characteristics

Data at high and low temperatures are applicable only within the recommended operating free-air temperature ranges of the various devices.

Figure 6-1. Reference Voltage vs Free-Air Temperature

Figure 6-2. Reference Current vs Free-Air Temperature

Figure 6-3. Cathode Current vs Cathode Voltage

Figure 6-4. Cathode Current vs Cathode Voltage

Figure 6-5. Off-State Cathode Current vs Free-Air Temperature

Figure 6-6. Ratio of Delta Reference Voltage to Delta Cathode Voltage vs Free-Air Temperature

TL431, TL432 SLVS543S – AUGUST 2004 – REVISED MAY 2024

TEXAS INSTRUMENTS www.ti.com

Figure 6-7. Equivalent Input Noise Voltage vs Frequency

Figure 6-8. Equivalent Input Noise Voltage Over a 10S Period

Figure 6-9. Test Circuit for Equivalent Input Noise Voltage Over a 10S Period

Figure 6-10. Small-Signal Voltage Amplification vs Frequency

Figure 6-11. Test Circuit for Voltage Amplification

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TL431, TL432 SLVS543S – AUGUST 2004 – REVISED MAY 2024

Figure 6-12. Reference Impedance vs Frequency

Figure 6-13. Test Circuit for Reference Impedance

Figure 6-14. Pulse Response

Figure 6-15. Test Circuit for Pulse Response

The areas under the curves represent conditions that can cause the device to oscillate. For curves B, C, and D, R2 and V+ are adjusted to establish the initial $V_{KA}$ and $I_{KA}$ conditions, with $C_L$ = 0. $V_{BATT}$ and $C_L$ then are adjusted to determine the ranges of stability.

Figure 6-16. Stability Boundary Conditions for All TL431 and TL431A Devices (Except for SOT23-3, SC-70, and Q-Temp Devices)

TEST CIRCUIT FOR CURVE A

TEST CIRCUIT FOR CURVES B, C, AND D

Figure 6-17. Test Circuits for Stability Boundary Conditions

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TL431, TL432

SLVS543S – AUGUST 2004 – REVISED MAY 2024

The areas under the curves represent conditions that can cause the device to oscillate. For curves B, C, and D, R2 and V+ are adjusted to establish the initial $V_{KA}$ and $I_{KA}$ conditions, with $C_L$ = 0. $V_{BATT}$ and $C_L$ then are adjusted to determine the ranges of stability.

Figure 6-18. Stability Boundary Conditions for All TL431B, TL432, SOT-23, SC-70, and Q-Temp Devices

TEST CIRCUIT FOR CURVES B, C, AND D

Figure 6-19. Test Circuit for Stability Boundary Conditions

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