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Texas Instruments TLVH431BQPKG3
- Part No.:
- TLVH431BQPKG3
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-243AA
- Datasheet:
-
TLVH431BQPKG3.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT89-3
- Quantity:
- Payment:
- Shipping:
Inventory:4,005
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Product details
Overview
TLVH431BQPKG3 from Texas Instruments is a low-voltage adjustable precision shunt regulator in SOT-89-3 package, featuring 1.24 V reference voltage with ±0.5% initial tolerance at 25°C, 100 μA minimum cathode current for regulation, and operation across –40°C to +125°C. It serves as an error amplifier or voltage reference in isolated flyback SMPS feedback loops, replacing Zener diodes with lower leakage and sharper turn-on.
For engineers reviewing the TLVH431BQPKG3 datasheet, TLVH431BQPKG3 pinout, TLVH431BQPKG3 application, or TLVH431BQPKG3 equivalent, key selection criteria include reference accuracy over temperature, dynamic impedance (0.25 Ω), cathode current range (100 μA–70 mA), and compatibility with optocoupler-based secondary-side regulation in 3.3 V systems.
Technical Context
The TLVH431BQPKG3 implements a bandgap-referenced error amplifier with Darlington output stage, enabling precise shunt regulation via external resistor divider between cathode and reference pins. Its internal 1.24 V reference is stable over –40°C to +125°C (Q-grade), with typical output impedance of 0.25 Ω and reference voltage drift of ≤31 mV across full temperature range.
It operates in two functional modes: open-loop comparator mode (e.g., voltage monitoring) requiring ≥100 μA cathode current, and closed-loop shunt regulator mode (e.g., SMPS feedback) where cathode voltage is set by R1/R2 ratio per VO = VREF × (1 + R1/R2) + Iref × R1. No external compensation capacitor is required for stability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (VREF) | 1.24 V ±0.5% at 25°C; sets minimum regulated output and defines accuracy baseline for adjustable configurations. |
| Operating Temperature Range | –40°C to +125°C (Q-grade); supports automotive under-hood and industrial high-temp environments without derating. |
| Cathode Current Range | 100 μA to 70 mA; enables ultra-low-power biasing and robust regulation in both standby and full-load conditions. |
| Dynamic Impedance | 0.25 Ω typical; ensures tight output voltage regulation under varying load and line conditions in feedback networks. |
| Reference Input Current (Iref) | 0.1–0.5 μA; minimizes resistor-divider loading error and supports high-impedance feedback design. |
| Output Voltage Range | VREF to 18 V; allows flexible adjustment for 3.3 V, 5 V, 12 V, and higher rails using two external resistors. |
| Thermal Resistance (RθJA) | 52 °C/W (SOT-89); enables >1 W power dissipation capability at TA = 25°C before reaching TJ(max) = 150°C. |
Pinout & Package
SOT-89-3 package (4.50 mm × 2.50 mm body size) with gull-wing leads; thermally enhanced tab connected to anode for PCB heat sinking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current input / output node | Primary connection point for feedback loop; sinks current to regulate voltage; must be biased above VREF for conduction. |
| REF (Pin 2) | Reference input / error-sense node | High-impedance input comparing external voltage to internal 1.24 V reference; requires ≥0.1 μA bias current. |
| ANODE (Pin 3) | Common return / ground reference | Low-impedance return path for cathode and reference currents; electrically tied to thermal tab for heat dissipation. |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage operation | Starts regulation at 1.24 V cathode-to-anode voltage - enables use in 1.8 V, 2.5 V, and 3.3 V systems where TL431 fails. |
| Ultra-low minimum cathode current | 100 μA maximum IK(min) - reduces quiescent power in always-on monitoring circuits and improves light-load efficiency in SMPS. |
| Integrated reference + amplifier | Eliminates need for external precision reference and op-amp in comparator or error-amplifier applications. |
| Stable without output capacitor | Internally compensated architecture avoids instability risks and layout sensitivity associated with external capacitors. |
| Low dynamic impedance | 0.25 Ω typical zKA - maintains <10 mV output deviation across 70 mA cathode current swing in shunt regulator mode. |
Applications
| Isolated Flyback SMPS Feedback | Voltage Monitoring & Threshold Detection |
|---|---|
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 sampled output to 1.24 V reference and drives optocoupler LED current. Use Value: Enables regulation down to 2.7 V output (1.24 V + opto Vf), with ±0.5% initial accuracy preserving system output tolerance budget. |
Use Scenario: Monitoring 5 V or 12 V power rail for undervoltage lockout or brownout detection. IC Role / Device Role / Timing Role: Comparator with integrated reference - triggers logic-level output when rail drops below programmable threshold. Use Value: Eliminates external reference and comparator IC; 0.1 μA Iref minimizes divider current, extending battery life in portable systems. |
| Zener Diode Replacement | Data Converter Reference |
Use Scenario: On-board 3.3 V or 5 V local regulation where space and leakage current are critical. IC Role / Device Role / Timing Role: Adjustable shunt regulator - replaces discrete Zener + series resistor with tighter tolerance and lower tempco. Use Value: 31 mV max VREF deviation over –40°C to +125°C vs >100 mV for typical 3.3 V Zener, improving long-term stability. |
Use Scenario: Providing stable reference voltage for SAR or delta-sigma ADCs in industrial data acquisition modules. IC Role / Device Role / Timing Role: Low-noise adjustable reference source - supplies clean, temperature-stable voltage to ADC reference input. Use Value: 0.25 Ω output impedance prevents reference droop during ADC conversion bursts; <1 μV/√Hz noise supports 16-bit+ resolution. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLVH431BQDBZR | SOT-23-3 package (2.92 mm × 1.30 mm); same electrical specs but smaller footprint and higher RθJA (206 °C/W). | Better suited for space-constrained PCBs where thermal mass is limited; requires careful thermal layout for >100 mW dissipation. | Select when board area is premium and power dissipation remains <150 mW; verify thermal performance with IR imaging. |
| TLVH432BQPKG3 | Identical Q-grade spec and SOT-89-3 package, but with REF–ANODE–CATHODE pinout (vs CATHODE–REF–ANODE in TLVH431BQPKG3). | Requires PCB layout revision; not drop-in compatible - pin 1 and pin 3 swapped relative to TLVH431BQPKG3. | Choose only if redesigning for TLVH432's alternate pinout; avoids signal routing conflicts in dense layouts with adjacent components. |
Compared with TLVH431BQDBZR, TLVH431BQPKG3 offers superior thermal performance (52 vs 206 °C/W) for higher-power regulation, while TLVH432BQPKG3 provides identical thermal and electrical behavior but mandates PCB rework due to reversed pin assignment - neither is pin-compatible with TLVH431BQPKG3.
Availability
TLVH431BQPKG3 is available at Aetrix Electronics and suitable for isolated power supplies, voltage supervision circuits, and precision analog references requiring stable component supply across automotive, industrial control, and telecom infrastructure programs.
Supply support for TLVH431BQPKG3 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 leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in precision reference and power IC design.
The TLVH431 family was designed specifically for low-voltage, high-accuracy shunt regulation in isolated and non-isolated power systems - targeting replacement of TL431 in next-generation 3.3 V and lower-rail applications.
FAQ
What is the reference voltage tolerance of TLVH431BQPKG3 at 25°C?
The TLVH431BQPKG3 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a VREF range of 1.234 V to 1.246 V. This B-grade accuracy is specified in Section 5.7 of the TI datasheet SLVS555N and applies exclusively to the Q-temperature grade (–40°C to +125°C) variant of the TLVH431BQPKG3 device.
Can TLVH431BQPKG3 operate with cathode voltage below 1.24 V?
No - TLVH431BQPKG3 requires cathode-to-anode voltage ≥1.24 V to enter regulation. Below this threshold, the device remains in cutoff with IK < 100 μA and cannot maintain reference accuracy. The absolute minimum operating VKA is 1.24 V, as confirmed in Section 5.3 Recommended Operating Conditions of the TLVH431BQPKG3 datasheet.
What is the maximum cathode current rating for TLVH431BQPKG3?
The TLVH431BQPKG3 supports continuous cathode current up to 70 mA, as specified in Section 5.3 Recommended Operating Conditions. Absolute maximum cathode current is 80 mA (Section 5.1), but sustained operation above 70 mA risks exceeding TJ(max) = 150°C unless thermal design accommodates the resulting power dissipation in the SOT-89 package.
How does TLVH431BQPKG3 differ from TLVH432BQPKG3?
TLVH431BQPKG3 and TLVH432BQPKG3 share identical electrical specifications and SOT-89-3 packaging, but differ in pinout: TLVH431BQPKG3 uses CATHODE–REF–ANODE (Pin 1–2–3), while TLVH432BQPKG3 uses REF–ANODE–CATHODE. This reversal makes them incompatible without PCB modification, as stated in the "TLVH432 provides alternative pinouts" feature description.
Is an output capacitor required for stability with TLVH431BQPKG3?
No - TLVH431BQPKG3 is internally compensated and stable without an output capacitor between cathode and anode. Section 7.3 Feature Description explicitly states this, and Figures 5-15 through 5-17 provide guidance only if external capacitance is added for specific transient response tuning - not for basic stability.
TLVH431BQPKG3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-243AA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 18 V
- Current - Output:
- 70 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:
- Surface Mount
- Supplier Device Package:
- SOT-89-3
TLVH431BQPKG3 FAQ
1.How can I place an order for TLVH431BQPKG3 through Aetrix?
Please submit a Request for Quotation (RFQ) for TLVH431BQPKG3 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 TLVH431BQPKG3 reliable?
The price and inventory of TLVH431BQPKG3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLVH431BQPKG3 is usually 5 days.
3.What payment methods are accepted for TLVH431BQPKG3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLVH431BQPKG3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TLVH431BQPKG3?
TLVH431BQPKG3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLVH431BQPKG3 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 TLVH431BQPKG3?
For technical support, including TLVH431BQPKG3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLVH431BQPKG3 requirements.
6.How does Aetrix verify that TLVH431BQPKG3 is sourced from the original manufacturer or authorized distributors?
All TLVH431BQPKG3 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 TLVH431BQPKG3 meets industry standards.
7.What is the process for return or replacement of TLVH431BQPKG3?
All TLVH431BQPKG3 units undergo pre-shipment inspection (PSI). If there is an issue with TLVH431BQPKG3, 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 TLVH431BQPKG3 part is unused and in its original packaging.
Return procedure for TLVH431BQPKG3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLVH431BQPKG3 Tags
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