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Texas Instruments TL431AIDCKR
- Part No.:
- TL431AIDCKR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 6-TSSOP, SC-88, SOT-363
- Datasheet:
-
TL431AIDCKR.pdf
- Description:
- IC VREF SHUNT ADJ 1% SC70-6
- Quantity:
- Payment:
- Shipping:
Inventory:15,999
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Product details
Overview
TL431AIDCKR from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, delivering 2.495 V nominal reference voltage with ±1% initial tolerance at 25°C, 0.2 Ω typical dynamic impedance, and sink-current capability from 1 mA to 100 mA. It operates across −40°C to 85°C and serves as a stable feedback element in isolated DC-DC converters and adjustable linear regulators.
For engineers reviewing the TL431AIDCKR datasheet, TL431AIDCKR pinout, TL431AIDCKR application, or TL431AIDCKR equivalent, this page provides verified electrical specifications, thermal performance data, stability boundary conditions, and real-world implementation guidance for power supply feedback loop design.
Technical Context
The TL431AIDCKR implements an internal error amplifier with sharp turn-on characteristics and active output circuitry, enabling precise regulation without external compensation in most configurations. Its three-terminal architecture (REF, CATHODE, ANODE) functions as a controllable current sink where cathode voltage is regulated relative to the reference input.
It features low temperature drift (14 mV over −40°C to 85°C), low output noise (260 nV/√Hz at 1 kHz), and stable operation up to 100 mA cathode current - making it suitable for closed-loop feedback in switching power supplies requiring tight output voltage accuracy and fast transient response.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V (nominal); ±1% tolerance at 25°C ensures ≤25 mV absolute error in feedback sensing. |
| Operating Temperature | −40°C to +85°C (I-grade); supports industrial power supply environments without derating. |
| Dynamic Impedance | 0.2 Ω typical; maintains stable regulation under load transients and minimizes output voltage deviation. |
| Cathode Current Range | 1 mA to 100 mA; enables direct interface with optocoupler LEDs or high-side current-sense resistors. |
| Reference Input Current | 2–4 µA typical; allows use of high-value feedback resistors (>1 MΩ) to reduce power loss and improve efficiency. |
| Temperature Drift | 14 mV max over full range; translates to <0.017%/°C average TC, critical for long-term output stability. |
| Output Noise | 260 nV/√Hz at 1 kHz; low enough to avoid compromising feedback loop SNR in precision SMPS designs. |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm), surface-mount, lead-free, RoHS-compliant. Pin 1 = REF, Pin 2 = CATHODE, Pin 3 = ANODE.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| REF (Pin 1) | Reference input | High-impedance threshold node; sets regulated cathode voltage via external resistor divider (VOUT = VREF × (1 + R1/R2)). |
| CATHODE (Pin 2) | Shunt current output | Current-sink terminal; sinks up to 100 mA to maintain regulation; connects to primary-side optocoupler LED in isolated flyback converters. |
| ANODE (Pin 3) | Common return | Ground reference for internal amplifier; must be connected to system ground or lowest potential point in feedback network. |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | 2.495 V to 36 V via two external resistors - eliminates need for multiple fixed-reference ICs in multi-output systems. |
| Low dynamic impedance | 0.2 Ω typical - ensures minimal output voltage shift during load steps, improving transient regulation in SMPS. |
| Sharp turn-on characteristic | Active output stage enables clean regulation onset without Zener-style soft knee - simplifies loop compensation. |
| Low reference input current | 2–4 µA - permits high-resistance feedback networks that reduce standby power and improve light-load efficiency. |
| Stability boundary data | Published CL vs. IKA stability curves (Fig 6-16/6-18) - enables reliable design of capacitive-loaded feedback paths without oscillation risk. |
Applications
| Rack Server Power Supply | Industrial AC/DC Converter |
|---|---|
Use Scenario: Secondary-side voltage feedback in isolated 48 V input / 12 V output LLC resonant converter. IC Role / Device Role / Timing Role: Shunt reference regulating optocoupler LED current to close primary-side PWM control loop. Use Value: ±1% reference accuracy maintains ±1.2% output voltage tolerance across line/load/temperature; 0.2 Ω impedance prevents feedback lag during 10 A step loads. |
Use Scenario: Output voltage regulation in 3-phase rectified 400 VAC-to-24 VDC industrial power module. IC Role / Device Role / Timing Role: Precision shunt reference in linear post-regulator stage following bulk DC-DC conversion. Use Value: 14 mV max temp drift ensures <±0.06% output variation over −40°C to 85°C ambient; low noise avoids interference with analog sensor interfaces. |
| AC Inverter Drive | Notebook PC Adapter |
Use Scenario: Feedback reference for auxiliary 15 V bias supply powering gate drivers and MCU in 3-phase motor inverter. IC Role / Device Role / Timing Role: Stable voltage reference for isolated flyback controller ensuring consistent gate drive voltage under variable load. Use Value: Sink-current capability up to 100 mA supports high-brightness optocoupler LEDs for robust isolation; SOT-23-3 footprint saves PCB space in compact drive modules. |
Use Scenario: Primary-side feedback reference in 19 V, 65 W GaN-based USB-C adapter with QR flyback topology. IC Role / Device Role / Timing Role: Programmable shunt reference setting output voltage via resistor divider tied to optocoupler cathode. Use Value: Low 2–4 µA reference current enables >1 MΩ top resistor, reducing no-load power below 30 mW - meeting DOE Level VI requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDCKR | 0.5% initial tolerance (vs. 1% for TL431AIDCKR); otherwise identical pinout, specs, and thermal rating. | Required where tighter output voltage accuracy (<±0.5%) is mandated, e.g., medical-grade power supplies. | Select TL431BIDCKR only if system-level calibration budget demands sub-1% reference contribution. |
| TL431ACDBVR | SOT-23-5 package (5-pin) with NC pins; same A-grade tolerance and −40°C to 85°C rating. | Used when board layout requires pin spacing compatibility with 5-pin footprints or legacy routing. | TL431ACDBVR is not pin-compatible; requires PCB redesign - choose only for mechanical or sourcing continuity reasons. |
Compared with TL431BIDCKR, TL431AIDCKR trades 0.5% accuracy for lower cost and broader availability; compared with TL431ACDBVR, it offers identical performance in a smaller 3-pin footprint, reducing layout area and assembly complexity.
Availability
TL431AIDCKR is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC converters, and notebook PC adapter designs requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for TL431AIDCKR 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 analog ICs and power management solutions.
The TL431 product line was designed specifically for high-accuracy, low-drift voltage regulation in isolated and non-isolated power supplies - targeting industrial, computing, and consumer power applications demanding reliability and long-term stability.
FAQ
What is the reference voltage tolerance of TL431AIDCKR at 25°C?
The TL431AIDCKR has a reference voltage tolerance of ±1% at 25°C, corresponding to a nominal 2.495 V output with a guaranteed range of 2.470 V to 2.520 V. This A-grade specification is confirmed in Section 6.8 of the TI SLVS543S datasheet and applies strictly to the TL431AIDCKR variant in SOT-23-3 packaging.
Does TL431AIDCKR support operation at −40°C?
Yes, TL431AIDCKR is rated for operation from −40°C to +85°C (I-grade temperature range). Its maximum reference voltage deviation over this full range is 14 mV, verified in Section 6.6 Electrical Characteristics for TL431I devices. The "I" suffix in TL431AIDCKR explicitly denotes this industrial temperature qualification.
What is the minimum cathode current required for regulation in TL431AIDCKR?
The TL431AIDCKR requires a minimum cathode current of 0.4 mA to maintain regulation, as specified in Section 6.8 (TL431AI characteristics). This value is confirmed across all I-grade variants and ensures stable operation even in ultra-low-power feedback paths using high-value resistors.
Can TL431AIDCKR replace a Zener diode in voltage reference circuits?
Yes, TL431AIDCKR is explicitly designed as a superior replacement for Zener diodes in precision regulation applications. Its active error amplifier delivers sharper turn-on, lower dynamic impedance (0.2 Ω vs. typical Zener's >10 Ω), and tighter voltage tolerance - enabling improved accuracy and stability in on-board regulation and switching power supplies.
What is the dynamic impedance of TL431AIDCKR and why does it matter?
The TL431AIDCKR has a typical dynamic impedance of 0.2 Ω, measured at 1 kHz with cathode current between 1 mA and 100 mA. This low value directly determines how much the output voltage shifts under load transients - critical for maintaining tight regulation in high-performance DC-DC converters where even millivolt deviations affect system behavior.
TL431AIDCKR 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:
- ±1%
- 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
TL431AIDCKR FAQ
1.How can I place an order for TL431AIDCKR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AIDCKR 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 TL431AIDCKR reliable?
The price and inventory of TL431AIDCKR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AIDCKR is usually 5 days.
3.What payment methods are accepted for TL431AIDCKR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AIDCKR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AIDCKR?
TL431AIDCKR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AIDCKR 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 TL431AIDCKR?
For technical support, including TL431AIDCKR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AIDCKR requirements.
6.How does Aetrix verify that TL431AIDCKR is sourced from the original manufacturer or authorized distributors?
All TL431AIDCKR 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 TL431AIDCKR meets industry standards.
7.What is the process for return or replacement of TL431AIDCKR?
All TL431AIDCKR units undergo pre-shipment inspection (PSI). If there is an issue with TL431AIDCKR, 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 TL431AIDCKR part is unused and in its original packaging.
Return procedure for TL431AIDCKR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431AIDCKR Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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AN431AN-ATRG1
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LM4040CYM3-2.5-TR
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LM4040CYM3-4.1-TR
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LM4040EIM3-2.5/NOPB
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AZ431LBNTR-G1
Diodes Incorporated
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LM4040D20IDBZR
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LM4041DIM3-ADJ/NOPB
Texas Instruments
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LM4040DIM3X-2.5/NOPB
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LM4040DIM3-2.5/NOPB
Texas Instruments
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AZ431LANTR-G1
Diodes Incorporated
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