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Texas Instruments TLV431BQPKG3
- Part No.:
- TLV431BQPKG3
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-243AA
- Datasheet:
-
TLV431BQPKG3.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT89-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,791
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Product details
Overview
TLV431BQPKG3 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±0.5% initial tolerance at 25°C, 0.25 Ω typical dynamic impedance, and operation down to 1.24 V cathode-anode voltage. It serves as a programmable voltage reference or error amplifier in isolated flyback power supplies, replacing Zener diodes in space-constrained 3.3 V systems.
For engineers reviewing the TLV431BQPKG3 datasheet, TLV431BQPKG3 pinout, TLV431BQPKG3 application, or TLV431BQPKG3 equivalent, key selection criteria include reference accuracy over –40°C to 125°C, minimum cathode current (55–100 µA), ultra-small SC-70 package footprint, and stability without output capacitance in closed-loop regulation.
Technical Context
The TLV431BQPKG3 implements a three-terminal shunt topology with an internal bandgap reference and NPN-based error amplifier driving a Darlington sink output stage. Its open-loop gain enables comparator operation with integrated 1.24 V reference, while closed-loop feedback via external resistors sets output voltage from 1.24 V to 6 V.
It operates across –40°C to 125°C (Q-grade), supports cathode voltages up to 6 V, requires ≥55 µA minimum cathode current for regulation, and maintains 11 mV max reference deviation over full temperature range. The device is internally compensated and stable without external output capacitance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (VREF) | 1.24 V nominal, ±0.5% tolerance at 25°C - enables precise low-voltage setpoints in feedback networks |
| Output Voltage Range | 1.24 V to 6 V - adjustable via two external resistors, supporting 3.3 V and 5 V supply regulation |
| Dynamic Impedance | 0.25 Ω typical - ensures tight regulation under load transients in shunt reference applications |
| Min Cathode Current (IK(min)) | 55 µA (typ), ≤100 µA (max) - allows operation in ultra-low-power flyback bias circuits |
| Temp Range (Q-grade) | –40°C to +125°C - qualified for automotive under-hood and industrial high-temp environments |
| VREF Drift | 11 mV max over –40°C to 125°C - guarantees stable reference in wide-temperature embedded systems |
| Package | SOT-89 (PK) - thermally robust 3-pin surface-mount package with 4.5 mm × 4.095 mm footprint |
Pinout & Package
SOT-89 (PK) package: 3-pin, single-ended, thermally enhanced plastic outline with exposed thermal pad (not electrically connected). Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REFERENCE.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current input/output node | Sinks regulated current; connects to optocoupler LED anode or feedback divider top node in SMPS |
| ANODE (Pin 2) | Common return path | Typically tied to system ground or power rail return; establishes reference potential for VKA |
| REFERENCE (Pin 3) | Feedback input / threshold sense | Compares external voltage to internal 1.24 V reference; requires ≥0.1 µA bias current for operation |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage operation | Starts regulating at VKA = 1.24 V - enables use in 1.8 V/2.5 V/3.3 V systems where TL431 cannot function |
| High initial accuracy | ±0.5% VREF tolerance (TLV431B grade) - reduces need for post-production calibration in precision supplies |
| Ultra-low IK(min) | 55 µA typical - permits biasing from high-impedance sources like resistor dividers in standby mode |
| Internal compensation | Stable without output capacitor - eliminates BOM cost and layout area for stability capacitor in most designs |
| Q-grade temperature range | –40°C to +125°C operation - meets AEC-Q100 stress test requirements for automotive power modules |
Applications
| Isolated Flyback 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 reference and error amplifier - compares output voltage against 1.24 V internal reference and drives optocoupler LED current. Use Value: Enables regulation down to 2.7 V output (1.24 V + opto VF), with 11 mV max VREF drift ensuring <±1% output accuracy over –40°C to 125°C. |
Use Scenario: On-board voltage clamping and precision biasing in low-voltage microcontroller peripherals. IC Role / Device Role / Timing Role: Programmable shunt regulator - replaces discrete Zener diodes with superior accuracy, lower knee current, and tighter tempco. Use Value: Reduces board area by 40% vs SOT-23-3 Zeners and eliminates calibration due to ±0.5% initial tolerance and 0.25 Ω dynamic impedance. |
| Voltage Monitoring | Comparator with Integrated Reference |
|
Use Scenario: Overvoltage/undervoltage detection in battery-powered IoT sensors operating from 3.0–4.2 V Li-ion cells. IC Role / Device Role / Timing Role: Precision threshold detector - uses internal 1.24 V reference to compare scaled input voltage via resistor divider. Use Value: Achieves trip-point accuracy of ±0.62% over temperature (±0.5% initial + 11 mV drift), eliminating external reference ICs and reducing component count. |
Use Scenario: Logic-level translation and signal conditioning in industrial PLC input modules with 24 V DC inputs. IC Role / Device Role / Timing Role: Open-loop comparator - sinks cathode current when REF voltage exceeds 1.24 V, providing clean digital output transition. Use Value: Integrates reference and comparator in one SC-70 package; 55 µA min cathode current enables direct drive from high-Z sensor outputs without amplification. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV431BQDBZR | SOT-23-3 (DBZ) package; same electrical specs, 2.92 mm × 2.37 mm footprint | Higher thermal resistance (RθJA = 206°C/W vs 52°C/W for PK); less suitable for >10 mA continuous dissipation | Select when board space is more critical than thermal performance and power dissipation remains <50 mW |
| TLVH431QPK | Wider VKA range (1.24 V to 18 V); higher IK rating (80 mA); same PK package | Supports higher-output-voltage SMPS (e.g., 12 V, 15 V) and higher-current bias networks | Select when designing >6 V regulated outputs or requiring >15 mA cathode current capability |
Compared with TLV431BQPKG3, TLV431BQDBZR trades thermal performance for smaller footprint, while TLVH431QPK extends voltage and current capability at identical package size-making TLV431BQPKG3 optimal for compact, thermally constrained 3.3 V/5 V isolated supplies requiring ±0.5% accuracy.
Availability
TLV431BQPKG3 is available at Aetrix Electronics and suitable for isolated flyback power supplies, precision voltage monitoring circuits, and low-voltage Zener replacement applications requiring stable component supply across automotive, industrial, and telecom end equipment.
Supply support for TLV431BQPKG3 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 delivering analog and embedded processing solutions, with leadership in precision analog, power management, and interface technologies.
The TLV431 family was designed specifically for low-voltage, high-accuracy shunt regulation in space-constrained power systems-including automotive infotainment, industrial PLCs, and isolated DC/DC converters-where traditional TL431 devices cannot operate.
FAQ
What is the reference voltage tolerance of TLV431BQPKG3 at 25°C?
The TLV431BQPKG3 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a VREF range of 1.234 V to 1.246 V per the datasheet's Section 5.7. This tight tolerance is specific to the 'B' grade and applies only at 25°C; full-range drift is specified separately as 11 mV over –40°C to 125°C. TLV431BQPKG3 achieves this accuracy without external trimming.
Can TLV431BQPKG3 be used in place of TL431 in existing designs?
TLV431BQPKG3 is not a direct drop-in replacement for TL431 due to its lower 1.24 V reference voltage (vs 2.5 V), reduced minimum cathode current (55 µA vs 1 mA), and different pinout in SOT-89. While both are 3-terminal shunt regulators, TLV431BQPKG3 requires redesign of feedback resistors and verification of bias current sufficiency. TLV431BQPKG3 is intended for new low-voltage designs, not legacy TL431 retrofits.
What is the maximum cathode voltage rating for TLV431BQPKG3?
The absolute maximum cathode-to-anode voltage (VKA) for TLV431BQPKG3 is 7 V, as specified in Section 5.1 of the datasheet. However, the recommended operating range is 1.24 V to 6 V per Section 5.3. Operating above 6 V risks violating recommended conditions and may impact long-term reliability or parametric performance, even if within absolute maximum limits.
Does TLV431BQPKG3 require an output capacitor for stability?
No, TLV431BQPKG3 is internally compensated and stable without an output capacitor between cathode and anode in standard shunt regulator configurations. This is confirmed in Section 7.3 and Figure 5-19 of the datasheet. An external capacitor may be added for noise filtering, but stability analysis (e.g., phase margin vs capacitive load) must be performed if capacitance exceeds 1 nF.
What is the thermal resistance (RθJA) of TLV431BQPKG3 in its SOT-89 package?
The junction-to-ambient thermal resistance (RθJA) for TLV431BQPKG3 in the PK (SOT-89) package is 52°C/W, as listed in Table 5.4. This value assumes standard JEDEC 2-layer board conditions. Actual thermal performance depends on PCB copper area, airflow, and solder joint quality; the exposed thermal pad (though unconnected) contributes to conduction cooling in typical layouts.
TLV431BQPKG3 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):
- 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:
- Surface Mount
- Supplier Device Package:
- SOT-89-3
TLV431BQPKG3 FAQ
1.How can I place an order for TLV431BQPKG3 through Aetrix?
Please submit a Request for Quotation (RFQ) for TLV431BQPKG3 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 TLV431BQPKG3 reliable?
The price and inventory of TLV431BQPKG3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLV431BQPKG3 is usually 5 days.
3.What payment methods are accepted for TLV431BQPKG3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLV431BQPKG3 transactions.
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4.How is shipping managed for TLV431BQPKG3?
TLV431BQPKG3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLV431BQPKG3 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 TLV431BQPKG3?
For technical support, including TLV431BQPKG3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLV431BQPKG3 requirements.
6.How does Aetrix verify that TLV431BQPKG3 is sourced from the original manufacturer or authorized distributors?
All TLV431BQPKG3 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 TLV431BQPKG3 meets industry standards.
7.What is the process for return or replacement of TLV431BQPKG3?
All TLV431BQPKG3 units undergo pre-shipment inspection (PSI). If there is an issue with TLV431BQPKG3, 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 TLV431BQPKG3 part is unused and in its original packaging.
Return procedure for TLV431BQPKG3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLV431BQPKG3 Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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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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