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Texas Instruments TLV431BQLPR
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- Part No.:
- TLV431BQLPR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
TLV431BQLPR.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:3,236
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Product details
Overview
TLV431BQLPR from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, 0.5% initial tolerance at 25°C, and operation from 1.24 V to 6 V output range. It delivers 0.25 Ω typical dynamic impedance, 80 µA typical cathode current, and supports secondary-side regulation in isolated flyback SMPSs.
For engineers reviewing the TLV431BQLPR datasheet, TLV431BQLPR pinout, TLV431BQLPR application, or TLV431BQLPR equivalent, this page provides verified electrical parameters, SC-70 package details, functional mode distinctions (open-loop comparator vs closed-loop shunt regulator), thermal performance data, and validated alternative options for voltage reference design.
Technical Context
The TLV431BQLPR implements an internal bandgap reference and NPN-based error amplifier driving a Darlington sink output stage. Its open-loop gain enables precise comparator operation with integrated 1.24 V reference, while closed-loop configuration with external resistive feedback achieves stable shunt regulation across 1.24–6 V.
It operates with ≥100 µA minimum cathode current for full regulation, exhibits –1.5 to –2.7 mV/V cathode voltage sensitivity, and maintains stability without output capacitance-though Figure 5-19 provides phase-margin guidance for capacitive load design.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (VREF) | 1.24 V ±0.5% at 25°C - sets precise trip point for comparator or regulation threshold in feedback loops |
| Output Voltage Range | 1.24 V to 6 V - adjustable via two external resistors, enabling compatibility with 3.3 V and 5 V systems |
| Dynamic Impedance | 0.25 Ω typical - ensures tight regulation under load transients and minimizes output voltage deviation |
| Cathode Current (IK,min) | 55–100 µA - defines minimum bias required to maintain regulation across –40°C to 125°C temperature range |
| Temperature Drift (VREF,dev) | 11 mV max (–40°C to 125°C) - corresponds to ±0.9 mV/°C average coefficient for high-stability reference designs |
| Reference Input Current (IREF) | 0.1–0.5 µA typical - enables high-impedance feedback networks without significant loading error |
| ESD Rating (HBM) | ±2000 V - meets industrial handling requirements without additional protection circuitry |
Pinout & Package
TLV431BQLPR is packaged in the ultra-small SC-70 (DCK) outline: 2.0 mm × 1.5 mm footprint, 0.95 mm height, 6-pin configuration with exposed pad option per TI packaging documentation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current/voltage input | Sink terminal for regulated current path; connects to optocoupler LED anode or feedback node in SMPS |
| REF (Pin 3) | Threshold reference input | High-impedance input sensing point; voltage at this pin is compared to internal 1.24 V reference |
| ANODE (Pin 6) | Common return path | Typically grounded; serves as current return for cathode and reference paths in standard configurations |
| NC (Pins 4, 5) | No internal connection | Unbonded pins; must be left floating-no routing or stitching required on PCB |
| Substrate (Pin 2) | Die attachment plane | Must be connected to ANODE or left open; not electrically active but critical for thermal and mechanical integrity |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage operation | 1.24 V reference enables regulation in 1.8 V, 2.5 V, and 3.3 V systems where TL431 (2.5 V) cannot function |
| Ultra-small SC-70 package | 2.0 mm × 1.5 mm footprint-40% smaller than SOT-23-3-reduces board area in space-constrained power modules |
| Integrated comparator + reference | Eliminates need for external voltage reference and op-amp in overvoltage/undervoltage monitoring circuits |
| Stable without output capacitor | Internally compensated architecture avoids mandatory output capacitance, simplifying layout and reducing BOM count |
| Wide temperature support | Qualified for –40°C to 125°C (Q-grade), supporting automotive under-hood and industrial motor drive applications |
Applications
| Isolated Flyback SMPS Regulation | Zener Diode Replacement |
|---|---|
|
Use Scenario: Secondary-side voltage sensing in 3.3 V isolated DC/DC converters using optocoupler feedback. IC Role / Device Role / Timing Role: Precision shunt regulator and error amplifier-compares output-derived voltage against 1.24 V reference and drives optocoupler LED current. Use Value: Enables regulation down to 2.7 V output (1.24 V + opto VF), improving efficiency and transient response over discrete Zener+transistor solutions. |
Use Scenario: On-board 2.5 V or 3.3 V rail stabilization in microcontroller power domains. IC Role / Device Role / Timing Role: Adjustable shunt reference-replaces fixed-voltage Zener diodes with programmable setpoint and lower dynamic impedance. Use Value: 0.25 Ω dynamic impedance reduces output voltage variation under load steps, improving ADC reference stability and analog sensor accuracy. |
| Voltage Monitoring & Threshold Detection | Programmable Current Sink |
|
Use Scenario: Undervoltage lockout (UVLO) or overvoltage protection (OVP) in battery-powered IoT nodes. IC Role / Device Role / Timing Role: Comparator with integrated reference-REF pin senses system voltage; CATHODE sinks current when threshold is exceeded. Use Value: 0.5% initial tolerance and 11 mV max drift over –40°C to 125°C ensure reliable trip points across environmental conditions without calibration. |
Use Scenario: Constant-current LED biasing or precision current source for sensor excitation. IC Role / Device Role / Timing Role: Adjustable current regulator-configured in closed loop with sense resistor between REF and ANODE to fix IOUT. Use Value: Cathode current control from 100 µA to 15 mA with <1% error enables accurate 12-bit DAC-equivalent current setting without external op-amps. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV431BIDBVR | SOT-23-3 package (DBZ), same 0.5% VREF tolerance and 1.24–6 V range, but 3-pin vs 6-pin DCK | Lacks NC and substrate pins; simpler layout but no thermal pad option and reduced thermal resistance margin | Select when board space allows larger SOT-23-3 and thermal performance below 125°C is sufficient |
| TLVH431BQDBVR | Wider cathode voltage range (1.24–18 V), higher IK rating (80 mA), SOT-23-3 package, same 0.5% tolerance | Supports higher-output SMPS topologies (e.g., 12 V, 15 V rails); not drop-in due to different pinout and higher minimum IK | Choose for >6 V output regulation or higher current capability; requires redesign of feedback network and layout |
Compared with TLV431BQLPR, TLV431BIDBVR offers identical electrical performance in a legacy 3-pin package but sacrifices thermal performance and board-area efficiency, while TLVH431BQDBVR extends voltage and current capability at the cost of compatibility and increased minimum cathode current requirement.
Availability
TLV431BQLPR is available at Aetrix Electronics and suitable for isolated power supplies, voltage monitoring circuits, and programmable current sources requiring stable component supply, high-precision references, and extended temperature operation.
Supply support for TLV431BQLPR 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 specializing in analog and embedded processing technologies, with leadership in precision analog ICs and power management solutions.
The TLV431 family was designed for low-voltage, high-accuracy shunt regulation and integrated comparator functions in space-constrained, thermally demanding applications such as isolated DC/DC converters and battery management systems.
FAQ
What is the maximum cathode voltage rating for TLV431BQLPR?
The absolute maximum cathode voltage (VKA) for TLV431BQLPR is 7 V, measured relative to the anode terminal. Exceeding this voltage risks permanent damage. In normal operation, the device regulates up to 6 V output, and the recommended operating range is 1.24 V to 6 V for stable shunt behavior.
Does TLV431BQLPR require an output capacitor for stability?
No, TLV431BQLPR is internally compensated and remains stable without an output capacitor between cathode and anode. However, if a capacitive load is added, Figure 5-19 in the datasheet provides phase-margin guidance to select values that avoid oscillation-especially critical in high-noise environments or fast-transient applications.
How does the substrate pin (Pin 2) on TLV431BQLPR affect thermal performance?
Pin 2 on TLV431BQLPR is the substrate connection and must be tied to the anode or left open-it is not electrically active but forms part of the thermal conduction path. When connected to ANODE (ground), it improves thermal resistance by ~10–15% in typical PCB layouts with thermal vias, enhancing reliability at 125°C ambient.
Can TLV431BQLPR replace TL431 in existing designs?
TLV431BQLPR can replace TL431 only in designs where the lower 1.24 V reference and reduced minimum cathode current (100 µA vs 1 mA) are acceptable. Pinout differs (6-pin SC-70 vs 3-pin TO-92/SOT-23), and voltage range is narrower (6 V vs 36 V), so direct substitution requires schematic and layout revision.
What is the typical reference input current (IREF) for TLV431BQLPR at 25°C?
The typical reference input current (IREF) for TLV431BQLPR is 0.1–0.5 µA at 25°C, with a maximum of 0.5 µA across the full temperature range. This ultra-low input current enables use with high-value feedback resistors (e.g., 1 MΩ) without introducing significant voltage division error or power loss.
TLV431BQLPR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- 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:
- ±0.5%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 100 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
TLV431BQLPR FAQ
1.How can I place an order for TLV431BQLPR through Aetrix?
Please submit a Request for Quotation (RFQ) for TLV431BQLPR 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 TLV431BQLPR reliable?
The price and inventory of TLV431BQLPR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLV431BQLPR is usually 5 days.
3.What payment methods are accepted for TLV431BQLPR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLV431BQLPR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TLV431BQLPR?
TLV431BQLPR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLV431BQLPR 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 TLV431BQLPR?
For technical support, including TLV431BQLPR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLV431BQLPR requirements.
6.How does Aetrix verify that TLV431BQLPR is sourced from the original manufacturer or authorized distributors?
All TLV431BQLPR 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 TLV431BQLPR meets industry standards.
7.What is the process for return or replacement of TLV431BQLPR?
All TLV431BQLPR units undergo pre-shipment inspection (PSI). If there is an issue with TLV431BQLPR, 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 TLV431BQLPR part is unused and in its original packaging.
Return procedure for TLV431BQLPR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLV431BQLPR Tags
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