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Texas Instruments TL431BQDE4
- Part No.:
- TL431BQDE4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TL431BQDE4.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,003
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Product details
Overview
TL431BQDE4 from Texas Instruments is a precision programmable shunt voltage reference IC with 0.5% initial tolerance at 25°C, adjustable output from 2.495 V to 36 V, and operation across –40°C to +125°C. It delivers 0.2 Ω typical dynamic impedance and supports 1–100 mA sink current, enabling high-accuracy feedback in isolated DC/DC converters and industrial power supplies.
For engineers reviewing the TL431BQDE4 datasheet, TL431BQDE4 pinout, TL431BQDE4 application, or TL431BQDE4 equivalent, this page provides verified electrical specifications, thermal performance data, stability boundary conditions, and automotive-grade (Q-temp) qualification details essential for safety-critical and high-reliability power regulation design.
Technical Context
The TL431BQDE4 implements an internal error amplifier and NPN transistor output stage configured as a three-terminal adjustable shunt regulator. Its reference input (REF) compares against an internal 2.495 V bandgap, driving cathode current to maintain precise voltage set by external resistive dividers.
Designed for Q-temp automotive qualification, it features 14–34 mV total reference voltage deviation over –40°C to +125°C and exhibits stable small-signal gain up to 100 kHz with <1 µV RMS low-frequency noise - critical for closed-loop feedback accuracy in servo drives and AC inverters.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±12 mV (typical); enables accurate 2.5 V–36 V programmable output via two external resistors |
| Initial Tolerance | ±0.5% at 25°C (B grade); ensures tight regulation without post-manufacturing calibration |
| Temp Range | –40°C to +125°C (Q grade); qualified for under-hood automotive and industrial ambient environments |
| Dynamic Impedance | 0.2 Ω typical (≤0.5 Ω max); maintains stable regulation under fast load transients in switching PSUs |
| Sink Current Range | 1 mA to 100 mA; supports direct interface with optocoupler LEDs and error amplifier outputs |
| Ref Input Current | 2–4 µA typical; minimizes divider resistor power loss and thermal drift in high-impedance feedback networks |
| Output Noise | <1 µV RMS (0.1–10 Hz); preserves signal integrity in precision analog feedback paths |
Pinout & Package
TL431BQDE4 is supplied in the SOIC-8 (D) package with 4.90 mm × 3.90 mm body size and standard 1.27 mm lead pitch. Pin 1 is CATHODE, Pin 2 is REFERENCE, Pin 3 is ANODE; Pins 4–8 are NC (no internal connection).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current output node | Connects to regulated rail or optocoupler LED anode; sinks current to maintain set voltage |
| REF (Pin 2) | Reference input | High-impedance comparator input tied to external resistor divider; threshold = 2.495 V |
| ANODE (Pin 3) | Common return path | Typically connected to system ground or negative rail; defines voltage reference point for REF |
| Pins 4–8 | No internal connection | Unused; must remain unconnected or grounded per layout guidelines to avoid parasitic coupling |
Key Features
| Feature | Design Value |
|---|---|
| Automotive-Qualified Operation | Rated for –40°C to +125°C free-air temperature; meets AEC-Q100 stress test requirements for automotive electronics |
| Low Dynamic Impedance | 0.2 Ω typical ensures minimal output voltage shift during 10–100 mA load steps in SMPS feedback loops |
| Stable Under Capacitive Loads | Validated stability with ≥0.1 µF to 10 µF capacitive loads at cathode - eliminates need for external compensation in most designs |
| Low Reference Input Current | 2–4 µA enables use of high-value feedback resistors (e.g., 1 MΩ), reducing power dissipation and self-heating errors |
| Sharp Turn-On Characteristic | Fast response (<1 µs rise time) allows reliable regulation in pulse-width modulated control schemes |
Applications
| AC Inverter Control | Rack Server PSU |
|---|---|
Use Scenario: Regulates DC bus voltage feedback in variable-frequency motor drives using isolated optocoupler interface. IC Role / Device Role / Timing Role: Shunt reference providing precise 2.5 V threshold for error amplifier comparison in secondary-side feedback loop. Use Value: 0.5% tolerance and 14 mV temp drift ensure ±0.5% output voltage accuracy across full operating temperature range. | Use Scenario: Secondary-side voltage reference in multi-output isolated DC/DC converters powering CPU, memory, and I/O rails. IC Role / Device Role / Timing Role: Programmable shunt regulator setting 12 V, 5 V, or 3.3 V outputs via resistor dividers and optocoupler-coupled feedback. Use Value: 100 mA sink capability directly drives PC817 optocoupler LED, eliminating need for external transistor buffer. |
| Industrial AC/DC Adapter | Servo Drive Power Module |
Use Scenario: Feedback reference in universal-input (85–265 VAC) offline flyback converters for factory automation equipment. IC Role / Device Role / Timing Role: Precision voltage reference establishing regulated 24 V output with tight line/load regulation. Use Value: Low 0.2 Ω dynamic impedance maintains ≤1% output variation during 50% load steps at 100 kHz switching frequency. | Use Scenario: Voltage sensing and regulation in high-current H-bridge gate driver power supplies. IC Role / Device Role / Timing Role: Shunt reference stabilizing auxiliary 15 V bias rail feeding isolated gate drivers and current sense amplifiers. Use Value: –40°C to +125°C operation ensures reliability in enclosed motor control cabinets with ambient temperatures up to 85°C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDR | Same B-grade accuracy and Q-temp rating, but in SOIC-8 package with identical pinout (D suffix) | Identical functional replacement; differs only in tape-and-reel packaging (DR vs DE4) | Select TL431BIDR for automated SMT assembly requiring 2500-unit reels |
| TL431CQDBVR | C-grade (1% tolerance), same Q-temp range, SOT-23-3 package (3-pin, different pinout) | Not pin-compatible; requires PCB redesign due to REF/CATHODE/ANODE reordering and smaller footprint | Choose only if ±1% tolerance suffices and board space constraints mandate SOT-23-3 |
Compared with TL431BQDE4, TL431BIDR offers identical electrical and thermal performance with reel packaging optimized for high-volume production, while TL431CQDBVR trades precision for compactness and requires layout changes - making TL431BQDE4 optimal for new designs demanding B-grade accuracy in standard SOIC-8.
Availability
TL431BQDE4 is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC adapters, and servo drive control modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431BQDE4 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 over 50 years of innovation in precision analog ICs.
The TL431 product line was engineered for high-accuracy voltage regulation in isolated power supplies, feedback control systems, and safety-critical industrial applications - emphasizing thermal stability, low noise, and robust transient response.
FAQ
What is the reference voltage tolerance of TL431BQDE4 at 25°C?
The TL431BQDE4 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 2.495 V nominal reference with ±12.5 mV deviation. This B-grade accuracy is specified in Section 6.13 of the TI SLVS543S datasheet and validated across production lots for automotive and industrial applications where tight regulation is mandatory.
Does TL431BQDE4 support operation at 125°C ambient temperature?
Yes, TL431BQDE4 is rated for operation from –40°C to +125°C ambient temperature (Q-grade qualification). Its electrical characteristics - including reference voltage deviation (14–34 mV), dynamic impedance (≤0.5 Ω), and sink current capability (1–100 mA) - are guaranteed across this full range per TI's SLVS543S specification table 6.13.
What is the maximum cathode voltage rating for TL431BQDE4?
The absolute maximum cathode voltage (VKA) for TL431BQDE4 is 37 V, with recommended operating range from Vref (≈2.495 V) to 36 V. Exceeding 37 V risks permanent damage; operation above 36 V violates recommended conditions and may degrade long-term reliability even if within absolute max limits.
Can TL431BQDE4 replace a Zener diode in a linear regulator design?
Yes, TL431BQDE4 is explicitly designed as a superior Zener diode replacement, offering sharp turn-on, 0.2 Ω dynamic impedance, and programmable output from 2.495 V to 36 V using two external resistors. Unlike Zeners, it maintains stable regulation across temperature and current - confirmed in TI's description section and Figure 6-16 stability analysis.
Is TL431BQDE4 pin-compatible with other TL431 variants in SOIC-8 packages?
Yes, TL431BQDE4 uses the standard SOIC-8 (D) pinout: Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE, Pins 4–8 = NC. All TL431x variants in SOIC-8 - including TL431BIDR and TL431AIDR - share this identical pin configuration and mechanical footprint, enabling drop-in substitution where grade and temp range align.
TL431BQDE4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.495V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 100 mA
- Tolerance:
- ±0.5%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 700 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
TL431BQDE4 FAQ
1.How can I place an order for TL431BQDE4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BQDE4 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 TL431BQDE4 reliable?
The price and inventory of TL431BQDE4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BQDE4 is usually 5 days.
3.What payment methods are accepted for TL431BQDE4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BQDE4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BQDE4?
TL431BQDE4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BQDE4 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 TL431BQDE4?
For technical support, including TL431BQDE4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BQDE4 requirements.
6.How does Aetrix verify that TL431BQDE4 is sourced from the original manufacturer or authorized distributors?
All TL431BQDE4 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 TL431BQDE4 meets industry standards.
7.What is the process for return or replacement of TL431BQDE4?
All TL431BQDE4 units undergo pre-shipment inspection (PSI). If there is an issue with TL431BQDE4, 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 TL431BQDE4 part is unused and in its original packaging.
Return procedure for TL431BQDE4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BQDE4 Tags
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TL431AIDBZR
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TL431BQDBZR
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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
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