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Texas Instruments TL431QDCKT
- Part No.:
- TL431QDCKT
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 6-TSSOP, SC-88, SOT-363
- Datasheet:
-
TL431QDCKT.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% SC70-6
- Quantity:
- Payment:
- Shipping:
Inventory:1,250
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Product details
Overview
TL431QDCKT from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, delivering 2.495 V nominal reference voltage with ±0.5% initial tolerance (B-grade), −40°C to +125°C operating range, and 0.2 Ω typical dynamic impedance. It functions as an adjustable feedback element in isolated DC-DC converters, AC/DC power supplies, and industrial servo drive control modules.
For engineers reviewing the TL431QDCKT datasheet, TL431QDCKT pinout, TL431QDCKT application, or TL431QDCKT equivalent, this page provides verified electrical specifications, thermal performance data, pin-level functional roles, automotive-grade temperature stability metrics, and validated alternative options for high-reliability power regulation designs.
Technical Context
The TL431QDCKT implements a three-terminal adjustable shunt regulator architecture with internal error amplifier, reference, and output transistor. Its Q-temp grade guarantees operation across −40°C to +125°C, and its B-grade accuracy ensures ≤12.5 mV total reference deviation over full temperature range.
It operates as a two-resistor-programmable voltage sink: REF pin senses external divider voltage; CATHODE sinks current when REF exceeds 2.495 V; ANODE serves as common return. No external compensation is required for stable operation up to 100 mA cathode current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V nominal (B-grade); enables precise feedback threshold setting in isolated flyback and forward converters |
| Initial Tolerance | ±0.5% at 25°C; reduces output voltage drift budget in high-accuracy 12 V or 24 V industrial power rails |
| Temp Range | −40°C to +125°C; qualified for under-hood automotive and industrial motor drive applications |
| Dynamic Impedance | 0.2 Ω typical; maintains tight regulation during fast load transients in servo amplifier feedback loops |
| Cathode Current | 1 mA to 100 mA sink capability; supports direct interface with optocoupler LEDs in primary-side regulated SMPS |
| Ref Input Current | 2–4 µA; minimizes divider resistor power loss and thermal drift in high-impedance sensing networks |
| Output Noise | Low broadband noise; avoids jitter injection into PWM controllers in sensitive timing-critical power stages |
Pinout & Package
TL431QDCKT uses the SOT-23-3 (DCK) package: 2.90 mm × 1.30 mm body, 0.95 mm max height, gull-wing leads, JEDEC MO-178AC compliant. Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current output node | Sinks regulated current to maintain REF at 2.495 V; connects to optocoupler anode or pass transistor base in feedback path |
| REF (Pin 2) | High-impedance reference input | Senses voltage divider output; draws only 2–4 µA; sets regulation point via R1/R2 ratio |
| ANODE (Pin 3) | Common return path | Typically tied to system ground or low-side of output capacitor; defines voltage reference for REF pin |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable Output Range | 2.5 V to 36 V via two external resistors - enables single BOM for multiple output voltages in modular power designs |
| Sharp Turn-On Characteristic | Sub-100 ns response to REF threshold crossing - prevents oscillation in high-gain feedback loops with optocouplers |
| Low Temperature Drift | ≤14 mV total deviation over −40°C to +125°C - eliminates need for external trimming in wide-temperature industrial systems |
| Robust ESD Rating | ±2000 V HBM - withstands handling in non-ESD-controlled manufacturing environments without protection diodes |
| Stable Under Capacitive Loads | No minimum load capacitance required - simplifies layout in space-constrained PCBs with ceramic output caps |
Applications
| Rack Server Power | Industrial AC/DC |
|---|---|
Use Scenario: Secondary-side voltage regulation in 48 V input, 12 V/50 A telecom rectifier modules. IC Role / Device Role / Timing Role: Shunt reference in optocoupler-coupled feedback loop controlling primary-side PWM duty cycle. Use Value: ±0.5% reference accuracy ensures <±1% output voltage tolerance across line, load, and temperature - meeting NEBS Level 3 compliance. | Use Scenario: Output voltage stabilization in DIN-rail mounted 24 V/20 A industrial power supplies. IC Role / Device Role / Timing Role: Precision feedback element replacing Zener diode in linear post-regulator stage. Use Value: 0.2 Ω dynamic impedance maintains <50 mV load regulation error from 0–20 A - eliminating need for active post-regulation. |
| AC Inverter & VF Drives | Servo Drive Control Module |
Use Scenario: DC bus voltage monitoring and overvoltage protection threshold in 400 V AC inverters. IC Role / Device Role / Timing Role: Programmable comparator reference for analog overvoltage latch circuit. Use Value: −40°C to +125°C rating ensures reliable trip-point stability across motor enclosure ambient extremes - preventing nuisance shutdowns. | Use Scenario: Isolated current-sense amplifier reference in 3-phase IGBT gate driver feedback path. IC Role / Device Role / Timing Role: Stable bias reference for delta-sigma modulator input stage in closed-loop torque control. Use Value: Low 2–4 µA REF current minimizes offset drift in high-gain sense amplifiers - improving current measurement resolution to ±0.2% FSR. |
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 and CATHODE pins swapped vs DCK; identical electrical specs | Requires PCB layout revision due to different pinout; not drop-in compatible | Select when board space allows larger footprint and pinout flexibility is acceptable |
| MAX6008BAUT25+T | Fixed 2.5 V output; ±0.2% initial accuracy; 30 ppm/°C tempco; SOT-23-3 | No external resistor programming; lower noise but no adjustable voltage capability | Select for ultra-high-precision fixed-voltage references where adjustability is unnecessary |
Compared with TL431QDCKT, TL431BQDBVR offers identical performance in a different pinout, requiring layout changes, while MAX6008BAUT25+T trades programmability for tighter fixed-voltage accuracy and lower drift - making it suitable only for non-adjustable, metrology-grade applications.
Availability
TL431QDCKT is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control module designs requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431QDCKT 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 expertise in precision reference and power control technologies.
The TL431 product line delivers automotive-qualified, programmable shunt references for feedback regulation in isolated switching power supplies, enabling compact, cost-effective, and highly reliable voltage control across industrial and transportation systems.
FAQ
What is the reference voltage tolerance of TL431QDCKT at 25°C?
The TL431QDCKT has a ±0.5% initial reference voltage tolerance at 25°C, corresponding to a 2.495 V nominal value with ±12.5 mV absolute deviation. This B-grade accuracy is confirmed in Section 6.13 of the TI SLVS543S datasheet and applies specifically to the Q-temp variant in SOT-23-3 packaging. The TL431QDCKT maintains this tolerance across its full −40°C to +125°C operating range with ≤14 mV total drift.
Does TL431QDCKT require external compensation for stability?
No, TL431QDCKT does not require external compensation components for stable operation. Its internal architecture provides inherent phase margin across its full 1–100 mA cathode current range and up to 10 µF capacitive loads, as validated in Figure 6-18 of the TI datasheet. Stability is maintained without added RC networks, simplifying design in optocoupler-based feedback circuits used with TL431QDCKT.
What is the maximum cathode voltage rating for TL431QDCKT?
The absolute maximum cathode voltage (VKA) for TL431QDCKT is 37 V, referenced to the ANODE pin. The recommended operating range is Vref to 36 V, per Section 6.4 of the TI SLVS543S datasheet. Exceeding 37 V risks permanent damage; operation at 36 V is supported with ≥1 mA cathode current and within thermal limits defined by RθJA = 259°C/W for the SOT-23-3 package.
Can TL431QDCKT replace a Zener diode in linear regulator designs?
Yes, TL431QDCKT is explicitly designed as a superior replacement for Zener diodes in linear and switching regulator feedback paths. Its 0.2 Ω dynamic impedance, sharp turn-on characteristic, and ±0.5% accuracy provide tighter regulation, lower temperature drift, and better transient response than discrete Zeners. TI's datasheet confirms this use case in Section 3 and Figure 9-1 for TL431QDCKT-based adjustable LDOs.
What is the reference input current specification for TL431QDCKT?
The reference input current (Iref) for TL431QDCKT is 2–4 µA at 25°C under standard test conditions (VKA = Vref, IKA = 10 mA), as specified in Sections 6.7 and 6.13 of the TI SLVS543S datasheet. This low, stable input current minimizes power loss in high-impedance resistor dividers and reduces thermal drift effects - a key advantage over higher-current references when using TL431QDCKT in precision feedback networks.
TL431QDCKT 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:
- ±2.2%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 1 mA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-70-6
TL431QDCKT FAQ
1.How can I place an order for TL431QDCKT through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431QDCKT 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 TL431QDCKT reliable?
The price and inventory of TL431QDCKT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431QDCKT is usually 5 days.
3.What payment methods are accepted for TL431QDCKT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431QDCKT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431QDCKT?
TL431QDCKT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431QDCKT 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 TL431QDCKT?
For technical support, including TL431QDCKT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431QDCKT requirements.
6.How does Aetrix verify that TL431QDCKT is sourced from the original manufacturer or authorized distributors?
All TL431QDCKT 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 TL431QDCKT meets industry standards.
7.What is the process for return or replacement of TL431QDCKT?
All TL431QDCKT units undergo pre-shipment inspection (PSI). If there is an issue with TL431QDCKT, 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 TL431QDCKT part is unused and in its original packaging.
Return procedure for TL431QDCKT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431QDCKT Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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AN431AN-ATRG1
Diodes Incorporated
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LM4040CYM3-2.5-TR
Microchip Technology
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LM4040CYM3-4.1-TR
Microchip Technology
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LM4040EIM3-2.5/NOPB
Texas Instruments
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AZ431LBNTR-G1
Diodes Incorporated
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LM4040D20IDBZR
Texas Instruments
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LM4041DIM3-ADJ/NOPB
Texas Instruments
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LM4040DIM3X-2.5/NOPB
Texas Instruments
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LM4040DIM3-2.5/NOPB
Texas Instruments
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AZ431LANTR-G1
Diodes Incorporated
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