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Texas Instruments TL431ACLPE3
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- Part No.:
- TL431ACLPE3
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
TL431ACLPE3.pdf
- Description:
- IC VREF SHUNT ADJ 1% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:150
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Product details
Overview
TL431ACLPE3 from Texas Instruments is a precision programmable shunt voltage reference IC with 1% initial tolerance at 25°C, adjustable output voltage from 2.47V to 36V, and operation across −40°C to 85°C. It delivers 0.2Ω typical dynamic impedance, 1–100mA sink-current capability, and low 6mV max temperature drift (I-grade), widely used in AC/DC power supplies and servo drive feedback loops.
For engineers reviewing the TL431ACLPE3 datasheet, TL431ACLPE3 pinout, TL431ACLPE3 application, or TL431ACLPE3 equivalent, key selection criteria include reference accuracy grade (A), thermal stability over industrial temperature range, cathode current compliance, dynamic impedance for loop stability, and SOT-23-3 package compatibility with space-constrained PCB layouts.
Technical Context
The TL431ACLPE3 implements a three-terminal adjustable shunt regulator architecture with an internal 2.495V bandgap reference, error amplifier, and NPN output stage. Its REF pin senses voltage relative to ANODE, enabling precise external resistor-based output programming between Vref and 36V.
It operates as a high-gain transconductance device: small deviations at REF modulate cathode current (IK) to maintain regulation, with sharp turn-on characteristics and low noise (<10µVRMS over 0.1–10Hz) making it suitable for closed-loop feedback in switching regulators and voltage monitors.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.47–2.52V at 25°C (1% A-grade tolerance); sets minimum programmable output voltage |
| Temperature Range | −40°C to +85°C (I-grade); validated for industrial ambient conditions without derating |
| Dynamic Impedance | 0.2Ω typical (≤0.5Ω max); ensures stable regulation under fast load transients |
| Cathode Current Range | 1–100mA continuous; supports direct feedback into PWM controllers or optocouplers |
| Reference Input Current | 2–4µA typical; enables high-impedance voltage divider networks with minimal error |
| Temp Drift (VI(dev)) | 14–34mV over full range; quantifies worst-case output deviation in closed-loop systems |
| Output Noise | <10µVRMS (0.1–10Hz); critical for precision analog sensing and low-noise power rails |
Pinout & Package
TL431ACLPE3 uses the SOT-23-3 (DBZ) package: 2.90mm × 1.30mm body, gull-wing leads, surface-mount compatible. Pin 1 = Cathode, Pin 2 = Reference, Pin 3 = Anode - all electrically active with no NC terminals.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Shunt current output node | Connects to regulated rail or optocoupler LED anode; sinks up to 100mA to maintain VREF |
| Reference (Pin 2) | High-impedance voltage sense input | Samples divided output voltage; draws only 2–4µA, minimizing divider loading error |
| Anode (Pin 3) | Common return path | Typically tied to system ground or negative rail; serves as voltage reference point for REF and VKA |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable Output Range | 2.47V to 36V via two external resistors - replaces discrete Zener diodes in wide-range feedback networks |
| Sharp Turn-On Characteristic | Fast response to REF voltage changes enables stable regulation in high-bandwidth SMPS feedback paths |
| Low Dynamic Impedance | 0.2Ω typical ensures minimal output voltage sag during 100mA load steps - critical for tight-tolerance rails |
| Industrial Temperature Rating | −40°C to +85°C operation verified per TI's I-grade characterization - eliminates need for thermal derating in embedded systems |
| Low Reference Input Current | 2–4µA maximum allows use of high-value resistor dividers (e.g., 1MΩ/100kΩ), reducing power loss and heat |
Applications
| AC/DC Power Supply Regulation | Servo Drive Feedback Loop |
|---|---|
Use Scenario: Secondary-side voltage regulation in isolated flyback converters using optocoupler feedback. IC Role / Device Role / Timing Role: Shunt reference providing precise 2.5V threshold to control optocoupler LED current and thus primary-side PWM duty cycle. Use Value: 1% initial accuracy and 14mV temp drift ensure ±1.5% output voltage stability across line/load/temperature - meeting EN 60950-1 requirements. |
Use Scenario: Voltage monitoring in motor control power stages to detect overvoltage faults before IGBT damage. IC Role / Device Role / Timing Role: Programmable comparator reference set to 32V, triggering shutdown when DC bus exceeds safe limit. Use Value: Adjustable 2.47–36V range and 100mA sink capability allow direct interface with protection logic without external amplification. |
| Industrial Rack Server PSU | Notebook PC Adapter Feedback |
Use Scenario: Precision 12V output regulation in multi-rail server power supplies with remote sensing. IC Role / Device Role / Timing Role: High-stability shunt reference in voltage divider network feeding digital controller ADC input. Use Value: 0.2Ω dynamic impedance minimizes sensing error under transient loads, maintaining <±0.5% output deviation during CPU burst cycles. |
Use Scenario: Isolated feedback in compact 19V/3.42A notebook adapters where board space limits component count. IC Role / Device Role / Timing Role: Compact SOT-23-3 shunt reference replacing larger TO-92 Zeners in optocoupler-coupled secondary regulation. Use Value: 2.90mm × 1.30mm footprint reduces PCB area by >60% vs legacy packages while maintaining 1% accuracy and thermal stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CDBZR | 0°C to 70°C operating range (C-grade), same 1% tolerance and SOT-23-3 package | Limited to commercial-temperature environments; unsuitable for industrial enclosures or uncooled chassis | Select when cost sensitivity outweighs extended temperature requirement and ambient stays below 70°C |
| TL431BIDBZR | 0.5% initial tolerance (B-grade), identical −40°C to 85°C range and SOT-23-3 footprint | Higher accuracy enables tighter output regulation in telecom power modules requiring ±0.5% specs | Choose when improved reference precision justifies ~15% higher unit cost and layout remains unchanged |
Compared with TL431CDBZR, TL431ACLPE3 adds 40°C lower minimum operating temperature for industrial reliability; compared with TL431BIDBZR, it trades 0.5% accuracy for lower cost while retaining full I-grade thermal performance - balancing precision, ruggedness, and BOM economics.
Availability
TL431ACLPE3 is available at Aetrix Electronics and suitable for AC/DC power supplies, servo drive control modules, and notebook PC power adapter designs requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.
Supply support for TL431ACLPE3 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 reference design and high-reliability power management ICs.
TL431ACLPE3 belongs to TI's precision shunt reference product line, engineered specifically for industrial and computing power systems demanding accurate, stable, and robust voltage regulation under variable thermal and load conditions.
FAQ
What is the reference voltage tolerance of TL431ACLPE3 at 25°C?
The TL431ACLPE3 has a 1% initial reference voltage tolerance at 25°C, meaning its Vref falls within 2.47V to 2.52V under nominal conditions. This A-grade specification is verified per TI's SLVS543S datasheet Section 6.8 and applies specifically to the I-temperature variant in SOT-23-3 packaging. The TL431ACLPE3 maintains this accuracy without calibration.
Can TL431ACLPE3 replace a Zener diode in a feedback circuit?
Yes, TL431ACLPE3 is explicitly designed as a superior replacement for Zener diodes in voltage regulation and feedback applications. Its 0.2Ω dynamic impedance, sharp turn-on characteristic, and adjustable 2.47–36V output enable more precise, stable, and temperature-resilient regulation than standard Zeners - especially in SMPS feedback loops where TL431ACLPE3 drives optocoupler LEDs directly.
What is the maximum cathode current supported by TL431ACLPE3?
TL431ACLPE3 supports a continuous cathode current range of 1mA to 100mA, as specified in Section 6.4 of the TI datasheet. This 100mA sink capability allows direct interface with optocoupler LEDs, transistor bases, or comparator inputs without external buffering - a key design advantage over lower-current references.
Does TL431ACLPE3 require external capacitors for stability?
TL431ACLPE3 does not require mandatory external compensation, but stability depends on load capacitance and cathode current. Per Figure 6-18 in the datasheet, oscillation risk exists above 10µF at low IK; for most applications, a 100nF ceramic capacitor from cathode to anode ensures robust phase margin. Layout and PCB parasitics also influence stability - refer to TI's recommended practices in Section 9.5.
What is the temperature coefficient behavior of TL431ACLPE3?
TL431ACLPE3 exhibits a maximum reference voltage deviation (VI(dev)) of 34mV over its full −40°C to +85°C operating range, corresponding to an effective temperature coefficient of approximately 43ppm/°C worst-case. This I-grade drift performance is documented in Section 6.6 and enables predictable output variation in industrial environments without additional thermal compensation.
TL431ACLPE3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Obsolete
- 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:
- Through Hole
- Supplier Device Package:
- TO-92-3
TL431ACLPE3 FAQ
1.How can I place an order for TL431ACLPE3 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431ACLPE3 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 TL431ACLPE3 reliable?
The price and inventory of TL431ACLPE3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431ACLPE3 is usually 5 days.
3.What payment methods are accepted for TL431ACLPE3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431ACLPE3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431ACLPE3?
TL431ACLPE3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431ACLPE3 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 TL431ACLPE3?
For technical support, including TL431ACLPE3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431ACLPE3 requirements.
6.How does Aetrix verify that TL431ACLPE3 is sourced from the original manufacturer or authorized distributors?
All TL431ACLPE3 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 TL431ACLPE3 meets industry standards.
7.What is the process for return or replacement of TL431ACLPE3?
All TL431ACLPE3 units undergo pre-shipment inspection (PSI). If there is an issue with TL431ACLPE3, 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 TL431ACLPE3 part is unused and in its original packaging.
Return procedure for TL431ACLPE3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431ACLPE3 Tags
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