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Texas Instruments TL431AIDCKT
- Part No.:
- TL431AIDCKT
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 6-TSSOP, SC-88, SOT-363
- Datasheet:
-
TL431AIDCKT.pdf
- Description:
- IC VREF SHUNT ADJ 1% SC70-6
- Quantity:
- Payment:
- Shipping:
Inventory:7,394
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Product details
Overview
TL431AIDCKT from Texas Instruments is a precision programmable shunt voltage reference in SOT-23-3 package, featuring 1% initial reference voltage tolerance at 25°C, adjustable output from 2.495 V to 36 V, and operation across −40°C to 85°C. 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 TL431AIDCKT datasheet, TL431AIDCKT pinout, TL431AIDCKT application, or TL431AIDCKT equivalent, key selection criteria include reference accuracy grade (A), thermal drift performance (14 mV over −40°C to 85°C), cathode current capability, dynamic impedance stability, and SOT-23-3 footprint compatibility with space-constrained power control designs.
Technical Context
The TL431AIDCKT implements a three-terminal adjustable shunt regulator architecture with an internal error amplifier, reference voltage cell, and NPN output stage. Its REF pin senses voltage relative to the ANODE, triggering cathode current modulation to maintain regulation - enabling precise closed-loop feedback without external op-amps.
It operates as a 2.495 V bandgap-referenced comparator driving a high-gain NPN transistor; the sharp turn-on characteristic and low 0.2 Ω dynamic impedance ensure stable regulation even under fast load transients. Temperature compensation is integrated to limit reference deviation to ≤14 mV across its full operating range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±1% at 25°C - sets minimum adjustable output; enables accurate 3.3 V, 5 V, 12 V, or custom rail regulation via two external resistors |
| Temp Range | −40°C to +85°C - qualified for industrial-grade power systems including motor drives and server PSUs |
| Dynamic Impedance | 0.2 Ω typical - ensures minimal output voltage shift under 1–100 mA cathode current variation; critical for loop stability |
| Cathode Current | 1–100 mA - supports direct drive of optocoupler LEDs or secondary-side feedback networks without buffering |
| Ref Input Current | 2–4 µA - enables high-impedance resistor dividers (e.g., 1 MΩ top/bottom) with negligible loading error |
| Output Noise | Low broadband noise - preserves signal integrity in precision feedback paths; no external filtering required in most applications |
| Thermal Drift | ≤14 mV over full temperature range - translates to <±50 ppm/°C average TC, ensuring <0.05% output variation across operating envelope |
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 (Pin 1) | Shunt current output node | Connects to primary-side controller feedback (e.g., UC384x COMP pin) or optocoupler anode; sinks regulated current to maintain VREF |
| REF (Pin 2) | Reference input threshold | Senses divided output voltage; when VREF = 2.495 V, device regulates - forms high-impedance sensing node for feedback divider |
| ANODE (Pin 3) | Common return/reference ground | Typically tied to system ground or secondary-side common; serves as voltage reference point for both REF and CATHODE terminals |
Key Features
| Feature | Design Value |
|---|---|
| 1% Initial Accuracy (A Grade) | Reduces need for post-manufacturing trimming in mid-precision power supplies; lowers BOM cost vs. 0.5% B-grade parts where tighter tolerance isn't required |
| 0.2 Ω Dynamic Impedance | Enables stable regulation under rapid load steps; eliminates need for large output capacitance to suppress ripple in flyback or forward converters |
| −40°C to +85°C Operation | Validated for industrial ambient conditions - supports deployment in servo drives, PLC power modules, and outdoor telecom equipment |
| 1–100 mA Sink Capability | Directly drives standard PC817/PC817x optocouplers across full CTR range without external transistor; simplifies isolated feedback design |
| Low Reference Input Current | Permits use of high-value feedback resistors (≥470 kΩ), minimizing standby power loss and improving light-load efficiency in energy-sensitive adapters |
Applications
| Rack Server Power | Industrial AC/DC |
|---|---|
Use Scenario: Secondary-side voltage regulation in 1U/2U server PSUs with active OR-ing and PMBus monitoring. IC Role / Device Role / Timing Role: Precision shunt reference in optocoupler-coupled feedback loop, setting +12 V and +3.3 V rails with <±1% accuracy. Use Value: Enables tight output tolerance compliance per ATX12VO spec while supporting dynamic load steps up to 50 A/ms without instability. |
Use Scenario: Output voltage stabilization in DIN-rail mounted 24 V/48 V industrial power supplies feeding PLC I/O modules. IC Role / Device Role / Timing Role: Adjustable reference controlling TL494 or UC384x PWM duty cycle via optocoupler feedback path. Use Value: Maintains <±1.5% output regulation across −25°C to +70°C ambient and 10–100% load, meeting IEC 61000-4 immunity requirements. |
| AC Inverter & VF Drives | Servo Drive Control Module |
Use Scenario: DC bus voltage sensing and regulation in 3-phase VFDs with regenerative braking and dynamic braking choppers. IC Role / Device Role / Timing Role: Shunt reference in isolated auxiliary supply feedback, stabilizing gate driver bias rails (±15 V) and MCU core voltage (3.3 V). Use Value: Ensures consistent gate drive strength across temperature, preventing shoot-through during high-frequency IGBT switching (up to 20 kHz). |
Use Scenario: Feedback reference for dual-output isolated DC/DC converter powering servo motor encoder interface and position controller FPGA. IC Role / Device Role / Timing Role: Primary-side voltage setpoint generator referenced to isolated ground, enabling precise 5.0 V ±1% and 3.3 V ±1% outputs. Use Value: Eliminates need for separate LDOs on secondary side; reduces component count and improves long-term drift stability of position feedback signals. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDBVR | Same SOT-23-3 package, but C-temp grade (0°C to 70°C) and 1% accuracy; lower thermal drift (6 mV max) but narrower operating range | Suitable only for commercial-grade applications like consumer adapters; not rated for industrial ambient extremes | Select when cost sensitivity outweighs extended temperature requirement and ambient stays within 0–70°C |
| TLVH431AILP | Lower 1.24 V reference voltage, 1% accuracy, same −40°C to 85°C range; higher 10 µA max reference current | Enables sub-2.5 V regulation (e.g., 1.8 V, 2.5 V LDO feedback); incompatible with legacy 2.495 V designs without resistor recalculations | Choose for new low-voltage systems requiring tighter headroom or multi-rail tracking; requires redesign of feedback network |
Compared with TL431ACDBVR, TL431AIDCKT offers guaranteed operation down to −40°C - essential for outdoor or factory-floor deployments - while TLVH431AILP enables lower-voltage regulation at the cost of higher reference current and non-drop-in replacement.
Availability
TL431AIDCKT is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control modules requiring stable component supply with traceable lot history and consistent parametric performance.
Supply support for TL431AIDCKT 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 family was designed as a pin-compatible, cost-optimized replacement for discrete Zener-based shunt regulators - targeting high-volume industrial, computing, and motor control power systems demanding reliability and thermal stability.
FAQ
What is the reference voltage tolerance of TL431AIDCKT at 25°C?
The TL431AIDCKT has a reference voltage tolerance of ±1% at 25°C, corresponding to a nominal 2.495 V output with a min/max range of 2.470 V to 2.520 V. This A-grade accuracy is confirmed in Section 6.8 of the TI SLVS543S datasheet and applies specifically to the TL431AIDCKT variant in SOT-23-3 packaging.
What temperature range does TL431AIDCKT support?
TL431AIDCKT is rated for operation from −40°C to +85°C, matching the TL431I grade specification. This industrial temperature range is validated per Section 6.6 of the official TI datasheet and ensures reliable performance in applications such as motor drives and DIN-rail power supplies exposed to wide ambient variations.
What is the dynamic impedance of TL431AIDCKT and why does it matter?
TL431AIDCKT exhibits 0.2 Ω typical dynamic impedance (|ZKA|) at frequencies ≤1 kHz and cathode currents from 1 mA to 100 mA. This low value ensures minimal output voltage deviation during load transients - a critical factor for maintaining stability in optocoupler-based feedback loops of isolated switch-mode power supplies.
Can TL431AIDCKT replace a Zener diode directly?
Yes, TL431AIDCKT can directly replace Zener diodes in shunt regulation applications, offering superior accuracy (±1% vs. ±5% typical for Zeners), lower dynamic impedance (0.2 Ω vs. ≥10 Ω), and adjustable output (2.495 V to 36 V). Its three-terminal configuration requires only two external resistors - no additional biasing components needed.
What is the maximum cathode current supported by TL431AIDCKT?
TL431AIDCKT supports continuous cathode current from 1 mA to 100 mA, as specified in Section 6.4 (Recommended Operating Conditions) and verified across all electrical characteristics tables in the TI datasheet. This range enables direct drive of standard optocouplers like PC817 without external amplification.
TL431AIDCKT 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
TL431AIDCKT FAQ
1.How can I place an order for TL431AIDCKT through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AIDCKT 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 TL431AIDCKT reliable?
The price and inventory of TL431AIDCKT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AIDCKT is usually 5 days.
3.What payment methods are accepted for TL431AIDCKT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AIDCKT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AIDCKT?
TL431AIDCKT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AIDCKT 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 TL431AIDCKT?
For technical support, including TL431AIDCKT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AIDCKT requirements.
6.How does Aetrix verify that TL431AIDCKT is sourced from the original manufacturer or authorized distributors?
All TL431AIDCKT 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 TL431AIDCKT meets industry standards.
7.What is the process for return or replacement of TL431AIDCKT?
All TL431AIDCKT units undergo pre-shipment inspection (PSI). If there is an issue with TL431AIDCKT, 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 TL431AIDCKT part is unused and in its original packaging.
Return procedure for TL431AIDCKT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431AIDCKT 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
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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