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Texas Instruments TL431ACPK
- Part No.:
- TL431ACPK
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-243AA
- Datasheet:
-
TL431ACPK.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT89-3
- Quantity:
- Payment:
- Shipping:
Inventory:3,249
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Product details
Overview
TL431ACPK from Texas Instruments is a precision programmable shunt voltage reference in SOT-89-3 package, delivering 2.495 V nominal reference voltage with ±0.5% 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 (I-grade) and serves as a stable feedback element in isolated DC-DC converters and adjustable linear regulators.
For engineers reviewing the TL431ACPK datasheet, TL431ACPK pinout, TL431ACPK application, or TL431ACPK equivalent, key selection criteria include its 1% initial accuracy (A-grade), thermal stability over industrial temperature range, low output noise, and compatibility with standard resistor-divider feedback networks in power supply control loops.
Technical Context
The TL431ACPK implements an internal error amplifier and NPN pass transistor in a three-terminal shunt topology, where the REF pin senses voltage relative to ANODE, and CATHODE sinks current to regulate VKA. Its sharp turn-on characteristic and low 0.2 Ω dynamic impedance enable fast transient response in closed-loop regulation.
Designed for industrial-grade operation (−40°C to 85°C), it exhibits ≤14 mV total reference voltage drift over temperature and maintains stable regulation down to 0.4 mA minimum cathode current-critical for low-power standby modes in AC/DC adapters and servo drives.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V nominal (2.47–2.52 V range at 25°C); sets precise feedback threshold for output voltage programming. |
| Initial Accuracy | ±1% at 25°C (A-grade); enables tight output voltage tolerance without trimming in production power supplies. |
| Operating Temperature | −40°C to +85°C; supports reliable operation in industrial motor drives and rack server power modules. |
| Dynamic Impedance | 0.2 Ω typical; ensures minimal output voltage perturbation under load transients in switching regulator feedback paths. |
| Sink Current Range | 1 mA to 100 mA; accommodates both light-load regulation and high-gain optocoupler drive in isolated flyback designs. |
| Reference Input Current | 2–4 µA; allows use of high-value feedback resistors (>1 MΩ) to minimize power loss in battery-backed systems. |
| Tempco Drift | ≤14 mV over full temperature range; guarantees <0.05%/°C effective tempco for stable long-term voltage setpoint. |
Pinout & Package
SOT-89-3 package: 3-pin surface-mount plastic package with exposed thermal pad (pin 2 connected to substrate and must be tied to ANODE or left open). Compact 4.5 mm × 2.5 mm footprint optimized for space-constrained power supply PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| REF (Pin 1) | Reference input | Senses voltage divider output; regulates when voltage equals internal 2.495 V bandgap reference. |
| ANODE (Pin 2) | Common return | Internal substrate connection; must be connected to system ground or shared reference node. |
| CATHODE (Pin 3) | Current sink output | Drives external optocoupler LED or series-pass transistor base; sinks up to 100 mA to maintain regulation. |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | Programmable from 2.495 V to 36 V using two external resistors-enables single BOM for multiple output rails. |
| Low output noise | Sub-20 µVRMS (0.1–10 Hz); preserves signal integrity in precision analog feedback and sensing circuits. |
| Sharp turn-on characteristic | Fast 1–2 µs response to reference threshold crossing-reduces regulation delay in dynamic load scenarios. |
| Thermal stability | Guaranteed ≤14 mV drift over −40°C to +85°C-eliminates need for external compensation in industrial environments. |
| High ESD robustness | ±2000 V HBM rating-survives handling and assembly without special ESD precautions. |
Applications
| Rack Server Power Supply | Industrial AC/DC Converter |
|---|---|
Use Scenario: Primary-side feedback in isolated 48 V–12 V DC-DC modules for telecom/datacom servers. IC Role / Device Role / Timing Role: Shunt reference providing precise voltage threshold to optocoupler-driven PWM controller. Use Value: Enables ±1% output voltage accuracy across line/load/temperature while reducing component count vs. discrete Zener+transistor solutions. |
Use Scenario: Output voltage regulation in 3 kW industrial rectifier with PFC front-end. IC Role / Device Role / Timing Role: Feedback reference for secondary-side synchronous rectifier controller. Use Value: Maintains stable 24 V rail under 10–100% load steps and −25°C to +70°C ambient, with no calibration required. |
| AC Inverter Drive | Servo Drive Control Module |
Use Scenario: Auxiliary 15 V bias supply regulation for gate drivers in 3-phase IGBT inverter stacks. IC Role / Device Role / Timing Role: Precision shunt reference in linear post-regulator stage following buck converter. Use Value: Delivers low-noise, thermally stable bias voltage critical for minimizing gate drive timing skew across parallel IGBTs. |
Use Scenario: Reference source for current-sense amplifier offset correction in closed-loop motor current control. IC Role / Device Role / Timing Role: Stable voltage reference for DAC output buffering and analog comparator thresholds. Use Value: Ensures <0.5% current loop accuracy over motor thermal cycling (−40°C to +85°C junction), improving torque consistency. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CPK | Standard grade (±2% initial accuracy), same SOT-89-3 package and pinout. | Limited to non-critical applications like basic voltage monitoring where ±2% tolerance is acceptable. | Select TL431CPK only if cost sensitivity outweighs output voltage accuracy requirements. |
| TL431BIPK | B-grade (±0.5% accuracy), industrial temperature range (−40°C to +85°C), identical SOT-89-3 mechanical form. | Enables tighter output regulation in high-precision servo and test equipment power supplies. | Choose TL431BIPK when <±0.5% initial tolerance and guaranteed low tempco are mandatory. |
Compared with TL431CPK, TL431ACPK offers 2× tighter initial accuracy and lower temperature drift-justifying its use in regulated outputs demanding ±1% stability. Versus TL431BIPK, it trades 0.5% accuracy for lower cost while retaining identical thermal performance and package compatibility.
Availability
TL431ACPK is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC converters, and servo drive control modules requiring stable component supply across extended temperature ranges and multi-year production cycles.
Supply support for TL431ACPK 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 control in power conversion systems, designed specifically for high-accuracy, low-drift voltage regulation in industrial, computing, and motor control applications.
FAQ
What is the reference voltage tolerance of TL431ACPK at 25°C?
The TL431ACPK has a reference voltage tolerance of ±1% at 25°C, corresponding to a 2.47 V to 2.52 V range around its 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 TL431ACPK variant with SOT-89-3 packaging and industrial temperature rating.
What is the operating temperature range for TL431ACPK?
The TL431ACPK is rated for operation from −40°C to +85°C, consistent with its "I" temperature suffix designation. This industrial-grade range is validated per Section 6.4 of the datasheet and ensures stable regulation in applications such as AC inverters and servo drives exposed to wide ambient variations.
How does TL431ACPK differ from TL431CPK?
The TL431ACPK uses A-grade silicon (±1% initial tolerance) versus the standard-grade (±2%) TL431CPK, while sharing identical SOT-89-3 packaging, pinout, and thermal specifications. Both operate from −40°C to +85°C, but TL431ACPK provides tighter voltage accuracy for applications requiring higher output regulation fidelity.
What is the minimum cathode current required for regulation in TL431ACPK?
The TL431ACPK requires a minimum cathode current of 0.4 mA to maintain regulation, as specified in Section 6.8 (Imin parameter). This low turn-on threshold enables efficient operation in standby modes of notebook PC adapters and low-power industrial sensors where quiescent current matters.
Can TL431ACPK replace a Zener diode in voltage reference circuits?
Yes-the TL431ACPK is explicitly designed as a superior replacement for Zener diodes in precision applications. Its active circuitry delivers sharper turn-on, lower dynamic impedance (0.2 Ω vs. typical Zener's >10 Ω), and programmable output (2.495 V to 36 V), making it ideal for on-board regulation and switching power supply feedback loops.
TL431ACPK Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-243AA
- 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:
- SOT-89-3
TL431ACPK FAQ
1.How can I place an order for TL431ACPK through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431ACPK 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 TL431ACPK reliable?
The price and inventory of TL431ACPK are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431ACPK is usually 5 days.
3.What payment methods are accepted for TL431ACPK?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431ACPK transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431ACPK?
TL431ACPK orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431ACPK 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 TL431ACPK?
For technical support, including TL431ACPK datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431ACPK requirements.
6.How does Aetrix verify that TL431ACPK is sourced from the original manufacturer or authorized distributors?
All TL431ACPK 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 TL431ACPK meets industry standards.
7.What is the process for return or replacement of TL431ACPK?
All TL431ACPK units undergo pre-shipment inspection (PSI). If there is an issue with TL431ACPK, 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 TL431ACPK part is unused and in its original packaging.
Return procedure for TL431ACPK:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431ACPK Tags
-
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
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
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