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Texas Instruments TL431ACDCKR
- Part No.:
- TL431ACDCKR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 6-TSSOP, SC-88, SOT-363
- Datasheet:
-
TL431ACDCKR.pdf
- Description:
- IC VREF SHUNT ADJ 1% SC70-6
- Quantity:
- Payment:
- Shipping:
Inventory:2,568
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Product details
Overview
TL431ACDCKR 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 at 25°C, 0.2 Ω typical dynamic impedance, and adjustable output from 2.495 V to 36 V via two external resistors. It operates across −40°C to 85°C (I-grade), supports 1–100 mA sink current, and serves as a Zener diode replacement in feedback loops of isolated DC/DC converters and AC/DC power supplies.
For engineers reviewing the TL431ACDCKR datasheet, TL431ACDCKR pinout, TL431ACDCKR application, or TL431ACDCKR equivalent, key selection criteria include reference accuracy over temperature, cathode current capability, thermal drift (14 mV max deviation over −40°C to 85°C), low noise performance, and compatibility with standard SOT-23-3 PCB footprints in space-constrained power regulation designs.
Technical Context
The TL431ACDCKR implements an internal op-amp-based error amplifier with sharp turn-on characteristics and active output circuitry, enabling stable closed-loop regulation without external compensation in most applications. Its three-terminal shunt architecture requires only two external resistors to set output voltage, with the REF pin sensing voltage relative to the ANODE (common ground node).
It features a 0.2 Ω typical dynamic impedance below 1 kHz, low 2 µA–4 µA reference input current, and maintains regulation down to 0.4 mA minimum cathode current. The device exhibits 14 mV maximum reference voltage deviation over its full operating temperature range (−40°C to 85°C), confirming suitability for industrial-grade power supply feedback paths.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V nominal (2.470–2.520 V range); sets precise feedback threshold for voltage regulation circuits |
| Initial Tolerance | ±0.5% at 25°C; enables high-accuracy output setting without trimming in production |
| Temp Range | −40°C to +85°C; qualified for industrial ambient conditions without derating |
| Dynamic Impedance | 0.2 Ω typical; ensures minimal output voltage shift under load transients |
| Cathode Current | 1–100 mA sink capability; supports direct drive of optocoupler LEDs in isolated flyback controllers |
| Ref Input Current | 2–4 µA; allows use of high-value feedback resistors to minimize power loss |
| Output Noise | Low broadband noise; critical for stable regulation in low-noise analog power rails |
Pinout & Package
SOT-23-3 package (2.90 mm × 1.30 mm body size) with gull-wing leads; compact footprint ideal for space-constrained power modules and adapter PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (CATHODE) | Shunt current/voltage input | Primary current-sink node; connects to switched node in feedback path (e.g., optocoupler anode) |
| Pin 2 (REF) | Threshold sense input | High-impedance reference comparator input; tied to resistor divider midpoint for voltage sensing |
| Pin 3 (ANODE) | Common return | Ground reference for both REF and CATHODE; must be connected to system ground or common return rail |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | Settable from 2.495 V to 36 V using two external resistors - eliminates need for multiple fixed-voltage references |
| Sharp turn-on characteristic | Active output stage delivers fast, clean regulation onset - prevents oscillation in poorly compensated feedback loops |
| Low output impedance | 0.2 Ω typical dynamic impedance - maintains stable reference under varying load and line conditions |
| Wide operating temperature | −40°C to +85°C rating - supports deployment in industrial motor drives and outdoor power equipment |
| Low reference current | 2–4 µA input current - enables high-resistance feedback networks for ultra-low quiescent power designs |
Applications
| Rack Server Power | Industrial AC/DC |
|---|---|
Use Scenario: Secondary-side voltage regulation in multi-output telecom rectifiers with optocoupler-isolated feedback. IC Role / Device Role / Timing Role: Precision shunt reference providing stable 5 V or 12 V feedback threshold to optocoupler LED driver. Use Value: ±0.5% initial accuracy and 14 mV temp drift ensure tight output voltage regulation across rack ambient variations. | Use Scenario: Output voltage sensing in DIN-rail mounted 24 V/48 V industrial power supplies. IC Role / Device Role / Timing Role: Adjustable shunt reference setting regulated output via resistor divider, interfacing with PWM controller error amp. Use Value: 1–100 mA sink current directly drives optocoupler LEDs without buffer transistor, simplifying BOM. |
| AC Inverter & VF Drives | Servo Drive Control Module |
Use Scenario: DC bus voltage monitoring and overvoltage protection threshold generation in variable-frequency motor drives. IC Role / Device Role / Timing Role: Programmable reference feeding comparator input to trigger shutdown when bus exceeds safe limit. Use Value: Adjustable 2.495–36 V range allows single part to cover multiple bus voltage classes (e.g., 300 V, 600 V, 800 V systems). | Use Scenario: Isolated feedback for auxiliary 5 V/3.3 V logic rails powering gate drivers and position encoder interfaces. IC Role / Device Role / Timing Role: Shunt reference stabilizing secondary-side LDO input or directly regulating isolated bias supply. Use Value: SOT-23-3 footprint enables placement near isolated transformer secondary, minimizing noise pickup in sensitive control circuits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431AIDBZR | SOT-23-3, A-grade (±1% tolerance), same I-temp range (−40°C to 85°C) | Lower accuracy acceptable where cost sensitivity outweighs tight regulation needs | Select when ±1% initial tolerance meets system spec and reduces unit cost |
| TL431BIDBZR | SOT-23-3, B-grade (±0.5% tolerance), same I-temp range but tighter VI(dev) spec (14 mV vs 14 mV - identical for this grade) | No functional difference in accuracy or temp drift; identical electrical behavior in TL431I family | Valid alternative if stock availability favors TI's B-grade variant; no design change required |
Compared with TL431ACDCKR, TL431AIDBZR trades ±0.5% accuracy for lower cost in less demanding applications, while TL431BIDBZR offers identical performance with potential sourcing flexibility - both share SOT-23-3 footprint and I-grade temperature qualification.
Availability
TL431ACDCKR is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control module designs requiring stable component supply, long-term manufacturability, and guaranteed traceable sourcing.
Supply support for TL431ACDCKR 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 delivers programmable shunt references for feedback loop stabilization in isolated and non-isolated power converters, designed specifically for industrial, computing, and motor control applications demanding high accuracy and reliability.
FAQ
What is the reference voltage tolerance of TL431ACDCKR at 25°C?
The TL431ACDCKR has a ±0.5% initial reference voltage tolerance at 25°C, corresponding to a 2.470 V to 2.520 V range around the nominal 2.495 V output. This A-grade accuracy is specified in Section 6.8 of the TI datasheet SLVS543S and applies strictly to the TL431ACDCKR variant with SOT-23-3 packaging and I-temperature rating.
What temperature range does TL431ACDCKR support?
TL431ACDCKR is rated for operation from −40°C to +85°C (I-grade), with maximum reference voltage deviation of 14 mV across that full range. This specification is confirmed in Section 6.9 (TL431AI electrical characteristics) and aligns with TI's device nomenclature where "I" denotes the industrial temperature grade.
How is the output voltage adjusted on TL431ACDCKR?
The output voltage of TL431ACDCKR is adjusted using two external resistors forming a voltage divider between cathode and anode, with the REF pin connected to the divider midpoint. The formula is VOUT = VREF × (1 + R1/R2), where VREF = 2.495 V. This configuration enables programmable outputs from 2.495 V to 36 V without internal trimming.
What is the minimum cathode current required for regulation in TL431ACDCKR?
TL431ACDCKR requires a minimum cathode current of 0.4 mA to maintain regulation, as specified in Section 6.8 under "Imin". This low threshold enables stable operation even with high-value feedback resistors and low-power optocouplers, reducing standby losses in energy-efficient power supplies.
Does TL431ACDCKR have a specified dynamic impedance value?
Yes, TL431ACDCKR has a typical dynamic impedance of 0.2 Ω, measured at frequencies ≤1 kHz with cathode current ranging from 1 mA to 100 mA (Section 6.8, |ZKA| parameter). This low impedance ensures minimal output voltage variation during load transients, supporting stable feedback in high-performance switching regulators.
TL431ACDCKR 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:
- 600 µA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-70-6
TL431ACDCKR FAQ
1.How can I place an order for TL431ACDCKR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431ACDCKR 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 TL431ACDCKR reliable?
The price and inventory of TL431ACDCKR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431ACDCKR is usually 5 days.
3.What payment methods are accepted for TL431ACDCKR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431ACDCKR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431ACDCKR?
TL431ACDCKR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431ACDCKR 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 TL431ACDCKR?
For technical support, including TL431ACDCKR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431ACDCKR requirements.
6.How does Aetrix verify that TL431ACDCKR is sourced from the original manufacturer or authorized distributors?
All TL431ACDCKR 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 TL431ACDCKR meets industry standards.
7.What is the process for return or replacement of TL431ACDCKR?
All TL431ACDCKR units undergo pre-shipment inspection (PSI). If there is an issue with TL431ACDCKR, 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 TL431ACDCKR part is unused and in its original packaging.
Return procedure for TL431ACDCKR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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