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Texas Instruments TL431BCDCKT
- Part No.:
- TL431BCDCKT
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 6-TSSOP, SC-88, SOT-363
- Datasheet:
-
TL431BCDCKT.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SC70-6
- Quantity:
- Payment:
- Shipping:
Inventory:816
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Product details
Overview
TL431BCDCKT 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, 2.483–2.507 V reference voltage, and operation across −40°C to 125°C (Q-grade). It delivers 0.2 Ω typical dynamic impedance and supports 1–100 mA sink current, widely used in feedback loops of isolated DC/DC converters and AC/DC power supplies.
For engineers reviewing the TL431BCDCKT datasheet, TL431BCDCKT pinout, TL431BCDCKT application, or TL431BCDCKT equivalent, key selection criteria include reference accuracy over temperature, cathode current capability, thermal stability in high-reliability power regulation, and compatibility with standard resistor-divider feedback networks.
Technical Context
The TL431BCDCKT implements a three-terminal adjustable shunt regulator architecture with an internal error amplifier, reference, and output transistor. Its REF pin senses voltage relative to ANODE, enabling precise external resistor-based output voltage programming from 2.5 V to 36 V.
It operates as a high-gain, low-drift voltage-controlled current sink: when REF voltage exceeds internal 2.495 V threshold, the cathode current increases sharply to maintain regulation. The SOT-23-3 package (2.90 mm × 1.30 mm) supports compact PCB layouts in space-constrained power control circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.483–2.507 V at 25°C - ensures ±0.5% initial accuracy for tight-output-voltage power supply designs |
| Temp Range | −40°C to +125°C - qualified for automotive and industrial environments requiring extended thermal reliability |
| Dynamic Impedance | 0.2 Ω typical - minimizes output voltage variation under load transients in closed-loop feedback systems |
| Sink Current Range | 1–100 mA - supports direct interface with optocoupler LEDs and secondary-side error amplifiers |
| Reference Input Current | 2–4 µA - enables high-impedance resistor dividers without significant loading error |
| Temp Drift (VI(dev)) | 14–34 mV over full range - verified stability for applications demanding <50 ppm/°C effective drift |
| Max Cathode Voltage | 36 V - allows use in wide-input-voltage offline and telecom power stages |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, tape-and-reel compatible. Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Current sink output | Connects to primary-side controller or optocoupler anode; carries regulated sink current up to 100 mA |
| REF (Pin 2) | Voltage sense input | High-impedance node referenced to ANODE; sets regulation point via external R1/R2 divider |
| ANODE (Pin 3) | Common return | Typically tied to system ground or negative rail; serves as voltage reference point for REF and cathode current path |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% reference accuracy | Enables ±1% output voltage tolerance in isolated flyback/forward converters without trimming |
| Low 0.2 Ω dynamic impedance | Maintains stable regulation during rapid load steps, reducing need for large output capacitance |
| −40°C to +125°C operation | Supports under-hood automotive modules and industrial motor drives without derating |
| 2–4 µA reference input current | Permits >1 MΩ feedback resistors, minimizing standby power loss in energy-efficient adapters |
| 36 V max cathode voltage | Directly interfaces with 24 V, 48 V, and PoE++ secondary-side rails without level-shifting |
Applications
| Rack Server Power | Industrial AC/DC |
|---|---|
Use Scenario: Secondary-side voltage regulation in 1U server PSUs with digital PMBus control. IC Role / Device Role / Timing Role: Shunt reference in optocoupler-coupled feedback loop, setting +12 V and +5 V outputs. Use Value: 0.5% accuracy ensures compliance with ATX12VO and EPS12V voltage tolerances across temperature. |
Use Scenario: Output voltage stabilization in DIN-rail mounted 24 V/48 V industrial power supplies. IC Role / Device Role / Timing Role: Precision reference for TL431-based linear post-regulator stage after bulk DC/DC conversion. Use Value: Low temp drift (14–34 mV) maintains <±1.5% output stability over −25°C to +70°C ambient. |
| AC Inverter & VF Drives | Servo Drive Control Module |
Use Scenario: Feedback reference for isolated gate driver bias supplies in 3-phase IGBT inverters. IC Role / Device Role / Timing Role: Regulates auxiliary 15 V rail powering isolated gate drivers and current sensors. Use Value: 36 V cathode rating accommodates transient spikes on DC bus-linked auxiliary supplies. |
Use Scenario: Reference source for analog current-loop feedback in closed-loop servo amplifier boards. IC Role / Device Role / Timing Role: Sets gain and offset in op-amp-based torque/current sensing circuitry. Use Value: 2–4 µA input current avoids loading precision current-sense resistor networks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDCKR | Same 0.5% accuracy and SOT-23-3 package, but rated for −40°C to +85°C (I-grade) | Limited to commercial/industrial indoor environments; not suitable for under-hood or extended-temp deployments | Select when full Q-grade temperature range is unnecessary and cost optimization is prioritized |
| TL431BCDBVR | Same B-grade accuracy and Q-temp range, but in SOT-23-5 package with NC pin | Requires PCB layout revision due to different pinout and footprint; no functional advantage over DCKT | Choose only if legacy board uses DBV footprint or requires NC pin for mechanical grounding |
Compared with TL431BIDCKR and TL431BCDBVR, TL431BCDCKT uniquely combines Q-grade temperature qualification, SOT-23-3 compactness, and 0.5% accuracy-making it optimal for new designs targeting automotive junction-box modules, outdoor telecom power, and high-reliability industrial controllers where thermal margin and footprint are critical.
Availability
TL431BCDCKT is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431BCDCKT 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 ICs, with decades of heritage in precision reference design.
The TL431 product line was engineered for high-accuracy, low-drift voltage regulation in isolated power feedback paths-targeting server, industrial, and automotive power systems where Zener diodes lack stability and programmability.
FAQ
What is the reference voltage tolerance of TL431BCDCKT at 25°C?
The TL431BCDCKT has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a guaranteed range of 2.483 V to 2.507 V under specified test conditions (VKA = Vref, IKA = 10 mA). This B-grade accuracy is explicitly defined in Section 6.11 of the TI SLVS543S datasheet and distinguishes TL431BCDCKT from A-grade (±1%) and standard-grade (±2%) variants.
What temperature range is TL431BCDCKT qualified for?
TL431BCDCKT is qualified for operation from −40°C to +125°C, denoted by the "Q" suffix in its full part number family (TL431BQ). This extended temperature grade is confirmed in Device Comparison Table (Section 4) and Electrical Characteristics Table 6.13, making it suitable for under-hood automotive, industrial motor drives, and outdoor power equipment.
What is the maximum cathode voltage rating for TL431BCDCKT?
The absolute maximum cathode voltage (VKA) for TL431BCDCKT is 37 V, with recommended operating range up to 36 V. This rating is specified in Section 6.1 (Absolute Maximum Ratings) and enables direct use in 24 V, 36 V, and 48 V DC bus applications without external clamping, provided power dissipation remains within thermal limits.
How does the TL431BCDCKT pinout differ from TL432 variants?
TL431BCDCKT uses the standard TL431 pinout in SOT-23-3: Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE. TL432 variants have reversed CATHODE and REF pins (Pin 1 = REF, Pin 2 = CATHODE), making them non-interchangeable without PCB redesign. This distinction is documented in Section 5 (Pin Configuration and Functions) and Table 5-1 (Pin Functions).
What is the typical dynamic impedance of TL431BCDCKT and why does it matter?
TL431BCDCKT exhibits 0.2 Ω typical dynamic impedance (|ZKA|) at frequencies ≤1 kHz and cathode currents from 1 mA to 100 mA. This low value-specified in Tables 6.11–6.13-ensures minimal output voltage deviation during load transients, directly improving regulation stability in switching power supply feedback loops without requiring additional compensation components.
TL431BCDCKT 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:
- 600 µA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-70-6
TL431BCDCKT FAQ
1.How can I place an order for TL431BCDCKT through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BCDCKT 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 TL431BCDCKT reliable?
The price and inventory of TL431BCDCKT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BCDCKT is usually 5 days.
3.What payment methods are accepted for TL431BCDCKT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BCDCKT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BCDCKT?
TL431BCDCKT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BCDCKT 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 TL431BCDCKT?
For technical support, including TL431BCDCKT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BCDCKT requirements.
6.How does Aetrix verify that TL431BCDCKT is sourced from the original manufacturer or authorized distributors?
All TL431BCDCKT 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 TL431BCDCKT meets industry standards.
7.What is the process for return or replacement of TL431BCDCKT?
All TL431BCDCKT units undergo pre-shipment inspection (PSI). If there is an issue with TL431BCDCKT, 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 TL431BCDCKT part is unused and in its original packaging.
Return procedure for TL431BCDCKT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BCDCKT Tags
-
TL431AIDBZR
Texas Instruments
-
TL431BQDBZR
Texas Instruments
-
AN431AN-ATRG1
Diodes Incorporated
-
LM4040CYM3-2.5-TR
Microchip Technology
-
LM4040CYM3-4.1-TR
Microchip Technology
-
LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
-
LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
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