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Texas Instruments TLV431ILPRE3
- Part No.:
- TLV431ILPRE3
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
TLV431ILPRE3.pdf
- Description:
- IC VREF SHUNT PREC ADJ TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,800
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Product details
Overview
TLV431ILPRE3 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±1.5% initial tolerance at 25°C, 0.25 Ω typical dynamic impedance, and operation down to 1.24 V cathode-anode voltage - used as an integrated reference in isolated flyback secondary-side regulation, Zener replacement, and voltage monitoring circuits.
For engineers reviewing the TLV431ILPRE3 datasheet, TLV431ILPRE3 pinout, TLV431ILPRE3 application, or TLV431ILPRE3 equivalent, this page delivers verified electrical specs, SC-70 package details, functional mode distinctions (open-loop comparator vs closed-loop shunt regulator), thermal performance data, and real-world selection guidance for power supply feedback design.
Technical Context
The TLV431ILPRE3 implements a bandgap-referenced error amplifier with Darlington output stage, enabling precise shunt regulation from 1.24 V to 6 V using two external resistors. Its internal reference is trimmed to 1.24 V with ±1.5% accuracy at 25°C and exhibits 11 mV max VREF deviation over –40°C to 125°C.
It operates in two distinct functional modes: open-loop comparator mode (with integrated 1.24 V threshold) and closed-loop shunt regulator mode (with 80 µA typical minimum cathode current and 0.25 Ω dynamic impedance). Stability is internally compensated - no output capacitor required - though phase margin vs capacitive load is characterized up to 1 nF.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF | 1.24 V nominal reference voltage; sets minimum adjustable output (1.24 V to 6 V) and defines trip point in comparator mode |
| VREF Tolerance | ±1.5% at 25°C; determines absolute accuracy of regulated voltage or threshold level in monitoring applications |
| IK(min) | 80 µA typical minimum cathode current; must be supplied to maintain regulation in shunt mode |
| |zKA| | 0.25 Ω typical dynamic impedance; ensures tight voltage regulation under load transients |
| VKA Range | 1.24 V to 6 V operating cathode-anode voltage; enables use in 3.3 V and lower-output isolated SMPS |
| TA Range | –40°C to 125°C (Q-grade); supports automotive under-hood and industrial high-temp environments |
| Package | SC-70 (DCK); 2.0 mm × 1.5 mm footprint - 40% smaller than SOT-23-3, ideal for space-constrained PCBs |
Pinout & Package
TLV431ILPRE3 is housed in a 6-pin SC-70 (DCK) package with exposed substrate pad. Pin 2 is substrate-connected and must be tied to ANODE or left floating per TI specification.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current sink input | Primary current path; connects to optocoupler LED anode or feedback node in isolated supplies |
| SUBSTRATE (Pin 2) | Internal die substrate connection | Must be connected to ANODE or left unconnected - not electrically active but critical for ESD robustness |
| ANODE (Pin 6) | Common return path | Typically grounded; serves as reference node for VREF measurement and cathode voltage definition |
| REF (Pin 3) | Reference input terminal | Compares external voltage to internal 1.24 V; requires ≥0.5 µA bias current for proper NPN base drive |
| NC (Pins 4, 5) | No internal connection | Unbonded; must remain unconnected on PCB to avoid parasitic coupling or ESD path disruption |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage operation | 1.24 V reference enables regulation in 3.3 V, 2.5 V, and 1.8 V systems where TL431 (2.5 V) cannot function |
| Ultra-small SC-70 package | 2.0 mm × 1.5 mm footprint reduces board area by 40% vs SOT-23-3 - critical for compact AC/DC adapters and IoT power modules |
| Integrated comparator + reference | Eliminates external voltage reference and op-amp in undervoltage lockout (UVLO) or overvoltage protection (OVP) circuits |
| Stable without output capacitor | Internally compensated architecture avoids stability risks from ceramic capacitor ESR/ESL - simplifies layout in noise-sensitive applications |
| Low IK(min) | 80 µA typical minimum cathode current allows efficient operation in low-power standby modes of SMPS controllers |
Applications
| Isolated Flyback Secondary Regulation | Zener Diode Replacement |
|---|---|
|
Use Scenario: Secondary-side voltage sensing in 3.3 V isolated flyback converters using optocoupler feedback. IC Role / Device Role / Timing Role: Adjustable shunt regulator and error amplifier - compares output-derived voltage to 1.24 V reference and drives optocoupler LED current. Use Value: Enables stable 3.3 V output with <2.7 V minimum regulation capability (1.24 V + opto VF), outperforming TL431 in low-voltage designs. |
Use Scenario: On-board 2.5 V or 3.3 V rail regulation where Zener diodes exhibit poor temperature stability and high dynamic impedance. IC Role / Device Role / Timing Role: Precision shunt reference - replaces discrete Zener + series resistor with 0.25 Ω impedance and ±1.5% accuracy. Use Value: Reduces output voltage drift by >5× vs 5% Zener diodes and eliminates need for trimming resistors in production calibration. |
| Adjustable Voltage Monitoring | Comparator with Integrated Reference |
|
Use Scenario: System-level undervoltage detection for microcontroller reset or battery charge termination. IC Role / Device Role / Timing Role: Threshold detector - REF pin biased to monitored voltage; CATHODE pulled low when threshold crossed. Use Value: Provides factory-trimmed 1.24 V reference with 11 mV max drift over –40°C to 125°C - eliminates external reference IC and saves BOM cost. |
Use Scenario: Simple logic-level translation or window comparator in sensor interface circuits. IC Role / Device Role / Timing Role: Open-loop comparator - uses internal 1.24 V reference to compare analog input against fixed threshold. Use Value: Delivers fast response with built-in reference, avoiding dual-component solutions (op-amp + reference) and reducing PCB footprint by 60%. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV431ACDBVR | 1% VREF tolerance at 25°C (vs 1.5% for TLV431ILPRE3); same SC-70 package and -40°C to 125°C rating | Better accuracy needed for precision feedback loops; identical pinout and layout compatibility | Select TLV431ACDBVR when ±1% reference accuracy is required without changing PCB layout or thermal design. |
| TLVH431ILP | Wider VKA range (1.24 V to 18 V); SOT-89-3 package; higher 80 mA cathode current capability | Required for >6 V output regulation or higher-current shunt applications; larger thermal footprint | Choose TLVH431ILP only when cathode voltage exceeds 6 V or >15 mA cathode current is needed - not drop-in compatible due to different package and pinout. |
Compared with TLV431ACDBVR, TLV431ILPRE3 trades ±1% accuracy for lower cost in less demanding feedback paths; compared with TLVH431ILP, it offers superior space efficiency and lower system cost where 6 V VKA and 15 mA IK are sufficient.
Availability
TLV431ILPRE3 is available at Aetrix Electronics and suitable for isolated flyback power supplies, voltage monitoring systems, and Zener-replacement circuits requiring stable component supply across automotive, industrial, and consumer electronics programs.
Supply support for TLV431ILPRE3 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor company designing analog ICs, embedded processors, and connectivity solutions for industrial, automotive, and communications markets.
The TLV431 family was developed as a low-voltage, precision alternative to the TL431 for modern 3.3 V and lower-power systems - emphasizing small footprint, wide temperature operation, and integrated functionality in shunt regulation and voltage monitoring.
FAQ
What is the reference voltage tolerance of TLV431ILPRE3 at 25°C?
The TLV431ILPRE3 has a ±1.5% reference voltage tolerance at 25°C, meaning its VREF falls between 1.222 V and 1.258 V under nominal conditions. This grade corresponds to the base TLV431 variant (not A or B suffix), and the full-range deviation is 11 mV over –40°C to 125°C. TLV431ILPRE3 maintains this tolerance without external calibration.
Can TLV431ILPRE3 replace a standard Zener diode in a 3.3 V regulator circuit?
Yes, TLV431ILPRE3 can directly replace a Zener diode in 3.3 V shunt regulation, offering superior performance: 0.25 Ω dynamic impedance (vs 10–100 Ω for Zeners), ±1.5% initial accuracy (vs ±5% typical for Zeners), and 11 mV max VREF drift over –40°C to 125°C. It requires only two external resistors to set output voltage and draws just 80 µA minimum cathode current.
What is the minimum cathode current required for TLV431ILPRE3 to regulate properly?
The TLV431ILPRE3 requires a minimum cathode current (IK(min)) of 80 µA typical to enter and maintain regulation. Below this, gain drops and regulation degrades. In practice, design for ≥100 µA to ensure reliable operation across temperature and process variation. This value is confirmed in Section 5.5 of the TLV431x datasheet for the Q-grade (–40°C to 125°C) version.
Does TLV431ILPRE3 require an output capacitor for stability?
No, TLV431ILPRE3 is internally compensated and stable without an output capacitor between CATHODE and ANODE. Unlike many shunt regulators, it does not require external capacitance for phase margin - simplifying layout and eliminating capacitor-related aging or ESR issues. However, if a capacitor is added, Figure 5-19 in the datasheet provides phase margin vs capacitive load guidance.
What package type is used for TLV431ILPRE3, and how does it differ from SOT-23-3?
TLV431ILPRE3 uses the SC-70 (DCK) package: 6-pin, 2.0 mm × 1.5 mm body size with exposed substrate pad. It is 40% smaller in footprint than SOT-23-3 (2.92 mm × 2.37 mm) and features different pinout - including NC pins and substrate connection (Pin 2). Layout redesign is required when migrating from SOT-23-3 variants like TLV431IDBZR.
TLV431ILPRE3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 6 V
- Current - Output:
- 15 mA
- Tolerance:
- ±1.5%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 80 µA
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
TLV431ILPRE3 FAQ
1.How can I place an order for TLV431ILPRE3 through Aetrix?
Please submit a Request for Quotation (RFQ) for TLV431ILPRE3 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for TLV431ILPRE3 reliable?
The price and inventory of TLV431ILPRE3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLV431ILPRE3 is usually 5 days.
3.What payment methods are accepted for TLV431ILPRE3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLV431ILPRE3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TLV431ILPRE3?
TLV431ILPRE3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLV431ILPRE3 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for TLV431ILPRE3?
For technical support, including TLV431ILPRE3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLV431ILPRE3 requirements.
6.How does Aetrix verify that TLV431ILPRE3 is sourced from the original manufacturer or authorized distributors?
All TLV431ILPRE3 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TLV431ILPRE3 meets industry standards.
7.What is the process for return or replacement of TLV431ILPRE3?
All TLV431ILPRE3 units undergo pre-shipment inspection (PSI). If there is an issue with TLV431ILPRE3, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The TLV431ILPRE3 part is unused and in its original packaging.
Return procedure for TLV431ILPRE3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLV431ILPRE3 Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
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AN431AN-ATRG1
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LM4040CYM3-2.5-TR
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LM4040CYM3-4.1-TR
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LM4040EIM3-2.5/NOPB
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AZ431LBNTR-G1
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LM4040D20IDBZR
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LM4041DIM3-ADJ/NOPB
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LM4040DIM3X-2.5/NOPB
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LM4040DIM3-2.5/NOPB
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AZ431LANTR-G1
Diodes Incorporated
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