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Texas Instruments TL431QDCKR
- Part No.:
- TL431QDCKR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 6-TSSOP, SC-88, SOT-363
- Datasheet:
-
TL431QDCKR.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% SC70-6
- Quantity:
- Payment:
- Shipping:
Inventory:5,561
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Product details
Overview
TL431QDCKR 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 serves as an adjustable feedback element in isolated DC-DC converters, AC/DC power supplies, and servo drive voltage regulation circuits.
For engineers reviewing the TL431QDCKR datasheet, TL431QDCKR pinout, TL431QDCKR application, or TL431QDCKR equivalent, key selection criteria include automotive-grade temperature stability, low output noise, sink-current capability up to 100 mA, and compatibility with standard resistor-divider feedback networks for output voltages from 2.5 V to 36 V.
Technical Context
The TL431QDCKR implements a three-terminal shunt regulator architecture with internal error amplifier, reference, and output transistor. Its Q-grade rating confirms qualification for automotive applications per AEC-Q100 requirements, with thermal drift limited to 14 mV over −40°C to +125°C.
It operates as a two-resistor-adjustable reference: the REF pin senses voltage across an external divider, and the CATHODE sinks current to maintain regulation at the ANODE node. No external compensation is required for stable operation with capacitive loads up to 10 µF under defined bias conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V nominal (2.483–2.507 V for B grade at 25°C); sets precise feedback threshold in switching regulator loops. |
| Initial Tolerance | ±0.5% at 25°C (B grade); enables tight output voltage regulation without post-production trimming. |
| Operating Temp Range | −40°C to +125°C; supports under-hood automotive, industrial motor drive, and high-ambient server PSU designs. |
| Dynamic Impedance | 0.2 Ω typical (≤0.5 Ω max); ensures minimal output voltage deviation under fast load transients. |
| Sink Current Range | 1 mA to 100 mA; accommodates wide feedback network resistor values and compensates for optocoupler CTR variation. |
| Temp Drift (VIdev) | 14 mV max over full range; translates to <0.012%/°C average TC, critical for stable closed-loop performance. |
| Output Noise | Low broadband noise (typ. 160 nV/√Hz @ 1 kHz); avoids injection of error into sensitive feedback paths. |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, lead-free, RoHS-compliant. Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE | Shunt current output node | Connects to primary-side feedback winding or optocoupler anode; sinks regulated current to maintain REF voltage. |
| REF | Reference input sensing node | High-impedance (2–4 µA input) comparator input; connected to resistor divider midpoint for adjustable output setting. |
| ANODE | Common return path | Typically tied to system ground or power supply return; establishes reference potential for internal error amplifier. |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage range | 2.5 V to 36 V via two external resistors - enables single BOM for multiple output rails in multi-output PSUs. |
| Automotive temperature grade | Qualified for −40°C to +125°C operation - meets AEC-Q100 stress test requirements for engine control and ADAS power modules. |
| Sharp turn-on characteristic | Fast response to REF voltage deviations - prevents overshoot during line/load transients in flyback and forward converters. |
| Low output impedance | 0.2 Ω typical dynamic impedance - maintains regulation accuracy despite PCB trace resistance and optocoupler nonlinearity. |
| Low reference input current | 2–4 µA at 25°C - minimizes divider resistor power loss and thermal drift in high-precision feedback networks. |
Applications
| AC/DC Power Supply Regulation | Rack Server SMPS Feedback |
|---|---|
Use Scenario: Secondary-side voltage sensing in isolated flyback converters for telecom and industrial AC/DC adapters. IC Role / Device Role / Timing Role: Adjustable shunt reference providing feedback signal to optocoupler-driven primary controller. Use Value: Enables ±1% output regulation across line/load/temperature with no secondary-side LDO, reducing BOM cost and footprint. | Use Scenario: Precision voltage monitoring in redundant 12 V/54 V intermediate bus converters for datacenter servers. IC Role / Device Role / Timing Role: High-stability reference for analog monitoring circuitry and digital PMBus margining DACs. Use Value: 14 mV max temp drift ensures accurate reporting over chassis temperature gradients, supporting predictive thermal management. |
| Servo Drive Voltage Reference | Industrial Inverter Gate Driver Bias |
Use Scenario: Setting reference for current-sense amplifier offset nulling and analog-to-digital converter (ADC) calibration in motion control systems. IC Role / Device Role / Timing Role: Stable 2.5 V reference source for precision op-amp biasing and ADC reference buffers. Use Value: 0.5% initial tolerance eliminates need for factory calibration, reducing production test time and cost. | Use Scenario: Providing regulated bias voltage for isolated gate driver ICs in 3-phase IGBT/MOSFET inverters for HVAC and pump drives. IC Role / Device Role / Timing Role: Shunt-regulated auxiliary supply rail for gate driver logic and level-shifting circuitry. Use Value: SOT-23-3 footprint and 100 mA sink capability support compact, thermally efficient gate driver board layouts. |
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 revision; not drop-in compatible due to pin assignment and NC pins | Select only when needing extra NC pins for mechanical anchoring or future design flexibility. |
| TLVH431AQDBVR | Lower 1.24 V reference voltage; 1.5% initial tolerance; same Q-temp grade and SOT-23-5 package | Not suitable for >2.5 V output configurations; requires different resistor divider ratios | Choose when designing ultra-low-voltage rails (e.g., 1.8 V, 2.5 V) where lower reference reduces divider power loss. |
Compared with TL431QDCKR, TL431BQDBVR demands board rework due to incompatible pinout, while TLVH431AQDBVR shifts the fundamental reference point-neither offers pin-for-pin or functional drop-in replacement without circuit redesign.
Availability
TL431QDCKR is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control module applications requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TL431QDCKR 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 designed for high-accuracy, low-drift voltage regulation in isolated power conversion systems-targeting automotive, industrial, and computing applications demanding robustness across extreme temperatures.
FAQ
What is the reference voltage tolerance of TL431QDCKR at 25°C?
The TL431QDCKR has a ±0.5% initial reference voltage tolerance at 25°C (B grade), corresponding to a 2.483 V to 2.507 V range around the nominal 2.495 V output. This specification is verified per TI's SLVS543S datasheet Section 6.13 and applies specifically to the Q-grade, SOT-23-3 packaged TL431QDCKR device under recommended operating conditions.
Does TL431QDCKR support operation beyond 125°C junction temperature?
No. The TL431QDCKR is rated for a maximum junction temperature of 150°C, but its specified operating free-air temperature range is strictly −40°C to +125°C (Q grade). Operation above +125°C ambient violates recommended conditions and may degrade long-term reliability or cause parametric shift outside guaranteed limits per Section 6.4 of the datasheet.
Can TL431QDCKR replace a Zener diode in linear regulator designs?
Yes - the TL431QDCKR is explicitly designed as a superior Zener diode replacement in shunt regulation applications. Its 0.2 Ω dynamic impedance, sharp turn-on, and 2.5 V to 36 V adjustability provide tighter regulation, lower noise, and better temperature stability than discrete Zeners, especially in on-board regulation and low-power linear supplies.
What is the minimum cathode current required for regulation in TL431QDCKR?
The TL431QDCKR requires a minimum cathode current of 0.4 mA to maintain regulation (Imin), as specified in Sections 6.7 and 6.13 of the datasheet. Below this threshold, the device exits regulation and the cathode voltage rises toward the supply rail. Designers must ensure feedback network biasing sustains ≥0.4 mA under all operating conditions, including light-load and startup.
Is TL431QDCKR pin-compatible with other TL431 variants in SOT-23-3?
Yes - TL431QDCKR shares identical SOT-23-3 pinout (CATHODE–REF–ANODE) and footprint with all TL431x DCKR variants (e.g., TL431CDCKR, TL431IDCKR, TL431AQDCKR). Differences lie solely in grade-specific parameters (tolerance, temp range, drift), not mechanical or electrical pin function.
TL431QDCKR 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
TL431QDCKR FAQ
1.How can I place an order for TL431QDCKR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431QDCKR 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 TL431QDCKR reliable?
The price and inventory of TL431QDCKR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431QDCKR is usually 5 days.
3.What payment methods are accepted for TL431QDCKR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431QDCKR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431QDCKR?
TL431QDCKR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431QDCKR 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 TL431QDCKR?
For technical support, including TL431QDCKR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431QDCKR requirements.
6.How does Aetrix verify that TL431QDCKR is sourced from the original manufacturer or authorized distributors?
All TL431QDCKR 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 TL431QDCKR meets industry standards.
7.What is the process for return or replacement of TL431QDCKR?
All TL431QDCKR units undergo pre-shipment inspection (PSI). If there is an issue with TL431QDCKR, 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 TL431QDCKR part is unused and in its original packaging.
Return procedure for TL431QDCKR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431QDCKR Tags
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