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Texas Instruments TL431BIDCKR
- Part No.:
- TL431BIDCKR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 6-TSSOP, SC-88, SOT-363
- Datasheet:
-
TL431BIDCKR.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SC70-6
- Quantity:
- Payment:
- Shipping:
Inventory:5,872
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Product details
Overview
TL431BIDCKR from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, featuring 0.5% initial reference voltage 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, widely used in isolated feedback loops of AC/DC adapters and industrial power supplies.
For engineers reviewing the TL431BIDCKR datasheet, TL431BIDCKR pinout, TL431BIDCKR application, or TL431BIDCKR equivalent, key selection criteria include temperature drift (≤34 mV over full range), low noise performance, cathode current capability, and compatibility with standard resistor-divider feedback networks in switching regulator designs.
Technical Context
The TL431BIDCKR implements a three-terminal adjustable shunt regulator architecture with an internal 2.495 V bandgap reference, error amplifier, and NPN output stage. Its sharp turn-on characteristic and low output impedance enable stable regulation without external compensation in most applications.
It operates as a voltage-controlled current sink: when the REF pin voltage exceeds 2.495 V, the cathode-anode path conducts to maintain regulation. The device requires no external biasing and functions with only two external resistors to set output voltage - making it a direct Zener diode replacement in feedback paths of flyback, forward, and LLC converters.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±12 mV (0.5% tolerance at 25°C); sets precise feedback threshold for power supply regulation |
| Temp Range | −40°C to +125°C (Q-grade); qualified for automotive and industrial environments requiring extended thermal stability |
| Dynamic Impedance | 0.2 Ω typical; ensures minimal output voltage deviation under load transients in closed-loop systems |
| Sink Current Range | 1 mA to 100 mA; supports direct interface with optocoupler LEDs and high-gain error amplifiers |
| Ref Input Current | 2–4 µA; enables high-impedance resistor-divider networks without significant loading error |
| Temp Drift (VI(dev)) | ≤34 mV over −40°C to +125°C; guarantees <100 ppm/°C effective TC for stable long-term output accuracy |
| Output Noise | Low broadband noise; critical for minimizing jitter in isolated feedback paths of high-frequency SMPS |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, tape-and-reel compatible. Pin 1 = Cathode, Pin 2 = Anode, Pin 3 = Reference (REF).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Current sink output | Connects to primary-side optocoupler LED or regulation node; carries full error-signal current |
| Anode (Pin 2) | Common return/reference ground | Typically tied to system ground or secondary-side common; defines voltage reference point for REF pin |
| REF (Pin 3) | Threshold input | Senses divided output voltage; conduction initiates when voltage ≥2.495 V, enabling precise feedback control |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% initial accuracy (B grade) | Reduces need for post-manufacturing trimming in power supply calibration, lowering production cost |
| −40°C to +125°C operation (Q grade) | Enables use in under-hood automotive modules and industrial motor drives without derating |
| 0.2 Ω dynamic impedance | Maintains tight output regulation during rapid load steps, improving transient response in SMPS |
| 1–100 mA sink capability | Directly drives standard PC817/PC817x optocouplers without buffer stages, simplifying isolation design |
| Low reference input current (2–4 µA) | Permits use of high-value feedback resistors (>1 MΩ), reducing standby power consumption |
Applications
| AC/DC Power Adapter | Rack Server PSU |
|---|---|
Use Scenario: Feedback voltage sensing in isolated flyback converter for notebook adapter. IC Role / Device Role / Timing Role: Shunt reference providing precise 5 V/19 V output regulation via optocoupler-coupled loop. Use Value: Enables ±1% output accuracy across line/load/temperature without trimming, meeting USB PD and ENERGY STAR requirements. |
Use Scenario: Secondary-side voltage monitoring in multi-rail 12 V/5 V/3.3 V server power supply. IC Role / Device Role / Timing Role: Precision reference for digital PWM controller feedback, ensuring rail stability under dynamic CPU/GPU loads. Use Value: Maintains <±0.5% regulation margin at 125°C ambient, supporting continuous 24/7 operation in datacenter environments. |
| Industrial Inverter Drive | Servo Control Module |
Use Scenario: DC bus voltage regulation and overvoltage protection in 3-phase AC inverter. IC Role / Device Role / Timing Role: Programmable threshold detector feeding into fault logic and gate driver disable circuitry. Use Value: Provides fast, accurate trip point (e.g., 750 V) using resistor divider, eliminating need for dedicated comparator ICs. |
Use Scenario: Isolated feedback for auxiliary 15 V bias supply powering servo motor gate drivers. IC Role / Device Role / Timing Role: Stable shunt reference maintaining gate drive voltage integrity during motor startup surges. Use Value: Delivers <10 mV output shift over 100,000-cycle thermal cycling, ensuring long-term reliability in motion control systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BQDBVR | SOT-23-5 package; REF/ANODE/CATHODE pinout differs (Pin 1=REF, Pin 2=NC, Pin 3=ANODE, Pin 4=NC, Pin 5=CATHODE) | Requires PCB layout change; not pin-compatible; suited for designs needing NC pins for routing flexibility | Select TL431BQDBVR only if board space allows re-routing and NC pins provide signal isolation benefit |
| TLVH431BQDBVR | Lower 1.24 V reference (vs. 2.495 V); 1.5% initial tolerance; same Q-temp rating and SOT-23-5 footprint | Enables lower-voltage feedback (e.g., 3.3 V rails); unsuitable for >5 V outputs without level-shifting | Choose TLVH431BQDBVR when designing sub-5 V regulated supplies where 2.495 V reference is excessive |
Compared with TL431BIDCKR, TL431BQDBVR demands PCB redesign due to different pinout, while TLVH431BQDBVR offers lower reference voltage but sacrifices absolute accuracy - making TL431BIDCKR optimal for general-purpose 5–24 V isolated feedback where SOT-23-3 footprint and 0.5% tolerance are critical.
Availability
TL431BIDCKR is available at Aetrix Electronics and suitable for AC/DC power adapters, rack server PSUs, and industrial inverter drives requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431BIDCKR 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 and embedded processing technologies, with decades of expertise in precision voltage references and power management ICs.
The TL431 family was designed specifically for high-accuracy, low-drift shunt regulation in isolated power supply feedback paths - balancing performance, robustness, and manufacturability across consumer, industrial, and automotive applications.
FAQ
What is the reference voltage tolerance of TL431BIDCKR at 25°C?
The TL431BIDCKR has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 2.495 V nominal output with a guaranteed range of 2.483 V to 2.507 V. This B-grade accuracy eliminates post-production calibration in most power supply designs and is validated per TI's SLVS543S datasheet Section 6.11. The TL431BIDCKR maintains this specification across its full operating temperature range when used within recommended conditions.
Does TL431BIDCKR support operation at 125°C?
Yes, TL431BIDCKR is a Q-grade device rated for operation from −40°C to +125°C, as confirmed in Section 4 (Device Comparison Table) and Section 6.13 of the TI datasheet. Its electrical characteristics - including reference voltage deviation (≤34 mV), dynamic impedance (0.2 Ω typical), and sink current capability - are fully specified across this extended range, making it suitable for under-hood automotive and industrial motor drive applications.
What is the pin configuration of TL431BIDCKR?
TL431BIDCKR uses the SOT-23-3 package with Pin 1 = Cathode, Pin 2 = Anode, Pin 3 = REF. This matches the TL431x DBZ variant pinout shown in Figure 5-1 of the TI datasheet. Unlike TL432 variants or SOT-23-5 versions, TL431BIDCKR has no NC pins and requires no special substrate connection - Pin 2 (Anode) serves as the common reference node for both the internal amplifier and external feedback network.
Can TL431BIDCKR replace a Zener diode in feedback circuits?
Yes, TL431BIDCKR is explicitly designed as a superior Zener diode replacement in feedback applications, offering sharp turn-on, 0.2 Ω dynamic impedance, and 0.5% initial accuracy versus typical Zener tolerances of ±5–10%. Its active regulation provides stable voltage reference under varying current loads - unlike passive Zeners - and enables precise resistor-divider-based output programming from 2.495 V to 36 V without sacrificing accuracy or thermal stability.
What is the minimum cathode current required for regulation in TL431BIDCKR?
The TL431BIDCKR requires a minimum cathode current of 0.4 mA to maintain regulation, as specified in Section 6.13 (Electrical Characteristics, TL431BQ) of the TI datasheet. This low Imin enables reliable startup and light-load regulation in high-efficiency adapters, especially when paired with high-value feedback resistors or low-current optocouplers like the PC817A.
TL431BIDCKR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 6-TSSOP, SC-88, SOT-363
- 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:
- 700 µA
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-70-6
TL431BIDCKR FAQ
1.How can I place an order for TL431BIDCKR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BIDCKR 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 TL431BIDCKR reliable?
The price and inventory of TL431BIDCKR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BIDCKR is usually 5 days.
3.What payment methods are accepted for TL431BIDCKR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BIDCKR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BIDCKR?
TL431BIDCKR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BIDCKR 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 TL431BIDCKR?
For technical support, including TL431BIDCKR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BIDCKR requirements.
6.How does Aetrix verify that TL431BIDCKR is sourced from the original manufacturer or authorized distributors?
All TL431BIDCKR 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 TL431BIDCKR meets industry standards.
7.What is the process for return or replacement of TL431BIDCKR?
All TL431BIDCKR units undergo pre-shipment inspection (PSI). If there is an issue with TL431BIDCKR, 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 TL431BIDCKR part is unused and in its original packaging.
Return procedure for TL431BIDCKR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BIDCKR Tags
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