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Nexperia USA Inc. TL431BQDBZR-QR
- Part No.:
- TL431BQDBZR-QR
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TL431BQDBZR-QR.pdf
- Description:
- IC VREF SHUNT 2.495V SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,534
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Product details
Overview
TL431BQDBZR-QR from Nexperia is a B-grade (±0.5 %) adjustable precision shunt regulator in SOT23 package, featuring 2.495 V reference voltage, 0.2 Ω dynamic cathode-anode impedance, and 1 mA to 100 mA sink current capability. It operates across –40 °C to +125 °C and is AEC-Q100 Grade 1 qualified for automotive feedback loops.
For engineers reviewing the TL431BQDBZR-QR datasheet, TL431BQDBZR-QR pinout, TL431BQDBZR-QR application, or TL431BQDBZR-QR equivalent, key selection criteria include reference voltage tolerance, thermal drift over automotive temperature range, cathode current compliance, dynamic output impedance, and SOT23 pin compatibility with existing shunt regulator layouts.
Technical Context
The TL431BQDBZR-QR implements a precision bandgap-based reference amplifier driving an NPN output stage, enabling sharp turn-on and stable regulation from 2.495 V to 36 V via two external resistors. Its functional diagram confirms direct cathode–anode–reference terminal topology without internal pass transistors or compensation networks.
It delivers 0.5 % initial Vref accuracy at 25 °C with ≤34 mV total variation over –40 °C to +125 °C, and maintains low 0.2 Ω ZKA up to 1 kHz - critical for high-frequency SMPS feedback stability and low-noise current sinking.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (Vref) | 2495 mV ±0.5 % at 10 mA cathode current - enables precise voltage setpoint with minimal resistor tolerance dependency |
| Cathode-Anode Voltage Range | 2.495 V to 36 V - supports wide-output adjustable regulation without external series pass devices |
| Sink Current Range | 1 mA to 100 mA - sufficient for optocoupler biasing and medium-power shunt control |
| Dynamic Impedance (ZKA) | 0.2 Ω typical below 1 kHz - ensures stable loop response in isolated SMPS feedback paths |
| Temperature Range | –40 °C to +125 °C - meets AEC-Q100 Grade 1 requirements for under-hood automotive use |
| Reference Current (Iref) | 2 µA to 4 µA - allows high-impedance resistor dividers without significant loading error |
| Output Noise | Low - specified by low ZKA and absence of noise-amplifying architecture in functional diagram |
Pinout & Package
SOT23 plastic surface-mounted package (3 leads), 1.9 mm × 1.1 mm × 1.0 mm body, standard pinning configuration per Table 3: Pin 1 = Cathode (K), Pin 2 = Reference (REF), Pin 3 = Anode (A).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - K (Cathode) | Current sink output node | Connects to regulated rail or optocoupler LED anode; carries full load current up to 100 mA |
| 2 - REF (Reference) | Precision voltage sense input | High-impedance node (2–4 µA) tied to resistor divider midpoint; sets output voltage via Vout = Vref × (1 + R1/R2) |
| 3 - A (Anode) | Return path / ground reference | Connected to system ground or low-side return; completes shunt current path and defines reference potential |
Key Features
| Feature | Design Value |
|---|---|
| Programmable output voltage | 2.495 V to 36 V using only two external resistors - eliminates need for multiple fixed-voltage regulators |
| B-Grade reference tolerance | ±0.5 % at 25 °C - reduces resistor trimming effort and improves closed-loop accuracy in safety-critical feedback |
| Automotive qualification | AEC-Q100 Grade 1 (–40 °C to +125 °C) - validated for engine control units, battery management, and ADAS power rails |
| Low dynamic impedance | 0.2 Ω typical - suppresses high-frequency noise coupling into feedback path and prevents oscillation in optocoupler-based SMPS |
| Sharp turn-on characteristic | Defined by active output circuitry - enables clean switching behavior versus Zener diodes, improving transient response in shunt limiter applications |
Applications
| Automotive SMPS Feedback | Precision Current Sink |
|---|---|
Use Scenario: Isolated flyback converter in vehicle infotainment power supply requiring stable 5 V output under varying load and temperature. IC Role / Device Role / Timing Role: Shunt regulator in secondary-side feedback loop, biasing PC817 optocoupler LED to regulate primary-side controller. Use Value: ±0.5 % Vref and 0.2 Ω ZKA maintain <1 % output deviation across –40 °C to +125 °C and suppress 100 kHz switching noise injection into REF pin. |
Use Scenario: Constant-current LED driver for dashboard backlighting with thermal derating requirement. IC Role / Device Role / Timing Role: Precision shunt current sink controlling LED string current independent of forward voltage variation. Use Value: 1–100 mA sink range and 2–4 µA Iref enable accurate current setting with 1 % resistor network, minimizing thermal drift impact. |
| On-Board Voltage Regulation | Adjustable Threshold Comparator |
Use Scenario: Local 3.3 V regulation for microcontroller I/O from 12 V battery rail in body control module. IC Role / Device Role / Timing Role: Three-terminal shunt regulator replacing Zener diode, dissipating excess current as heat. Use Value: Sharp turn-on and 0.5 % Vref ensure stable 3.3 V output with <50 mV ripple, even during cold-crank (6.5 V input) and load dump (36 V transients). |
Use Scenario: Overvoltage detection circuit triggering shutdown when battery voltage exceeds 15.2 V. IC Role / Device Role / Timing Role: Single-supply comparator with temperature-compensated threshold using TL431BQDBZR-QR as reference and sensing node. Use Value: Bandgap-derived 2.495 V reference and <34 mV total Vref drift over –40 °C to +125 °C yield ±0.1 V threshold accuracy without external calibration. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431AQDBZR-Q | 1 % Vref tolerance, same SOT23 pinout and –40 °C to +125 °C rating | Lower accuracy requirement; acceptable where ±1 % output regulation suffices | Select when cost sensitivity outweighs need for 0.5 % precision in non-safety-critical subsystems |
| TL431CDBZR-Q | 2 % Vref tolerance, same package and temperature range | General-purpose industrial or consumer power supplies with relaxed regulation specs | Choose for cost-optimized designs where reference drift and resistor tolerance dominate overall error budget |
Compared with TL431AQDBZR-Q and TL431CDBZR-Q, the TL431BQDBZR-Q provides tighter initial Vref accuracy and lower total drift over temperature - directly reducing output voltage error in automotive feedback and precision current sink applications without increasing component count or layout area.
Availability
TL431BQDBZR-QR is available at Aetrix Electronics and suitable for automotive power conversion, precision current limiting, and on-board voltage regulation requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431BQDBZR-QR 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
Nexperia is a leading semiconductor manufacturer specializing in high-performance, high-reliability logic, analog, and discrete components, with strong focus on automotive and industrial applications.
The TL431-Q family is designed specifically for automotive-grade precision voltage regulation and feedback control, targeting AEC-Q100-compliant systems where reliability, thermal stability, and tight reference tolerance are mandatory.
FAQ
What is the maximum cathode-anode voltage for TL431BQDBZR-QR?
The absolute maximum cathode-anode voltage is 37 V per Table 6. The recommended operating range extends from Vref (2.495 V) up to 36 V. Exceeding 37 V risks permanent damage; operation above 36 V is not guaranteed for regulation stability or parametric performance.
Does TL431BQDBZR-QR require an external capacitor on the REF pin?
Yes - a small capacitor (~100 pF) is recommended at the REF pin to damp high-frequency switching noise injected from the primary side in SMPS feedback applications, as shown in Figure 26. This prevents instability and false triggering due to noise coupling into the high-impedance reference node.
How does the mirrored pinning variant differ from TL431BQDBZR-QR?
TL431BQDBZR-QR uses standard SOT23 pinning (Pin 1 = K, Pin 2 = REF, Pin 3 = A). Mirrored variants like TL431BMFDT-Q swap Pin 1 and Pin 2 (Pin 1 = REF, Pin 2 = K), making them electrically incompatible without PCB layout revision. Always verify marking code CJ% and ordering code suffix to confirm pinning.
Can TL431BQDBZR-QR be used in parallel for higher current capacity?
No - paralleling TL431 devices is not recommended due to mismatched reference voltages and thermal runaway risk. Each unit must regulate independently. For >100 mA sink current, use a single TL431BQDBZR-QR driving an external NPN/PNP transistor configured as a high-current shunt stage, as shown in Figure 24.
TL431BQDBZR-QR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- 600 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3 (TO-236)
TL431BQDBZR-QR FAQ
1.How can I place an order for TL431BQDBZR-QR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BQDBZR-QR 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 TL431BQDBZR-QR reliable?
The price and inventory of TL431BQDBZR-QR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BQDBZR-QR is usually 5 days.
3.What payment methods are accepted for TL431BQDBZR-QR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BQDBZR-QR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BQDBZR-QR?
TL431BQDBZR-QR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BQDBZR-QR 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 TL431BQDBZR-QR?
For technical support, including TL431BQDBZR-QR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BQDBZR-QR requirements.
6.How does Aetrix verify that TL431BQDBZR-QR is sourced from the original manufacturer or authorized distributors?
All TL431BQDBZR-QR 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 TL431BQDBZR-QR meets industry standards.
7.What is the process for return or replacement of TL431BQDBZR-QR?
All TL431BQDBZR-QR units undergo pre-shipment inspection (PSI). If there is an issue with TL431BQDBZR-QR, 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 TL431BQDBZR-QR part is unused and in its original packaging.
Return procedure for TL431BQDBZR-QR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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