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Texas Instruments TL431BCLPE3
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- Part No.:
- TL431BCLPE3
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
TL431BCLPE3.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,941
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Product details
Overview
TL431BCLPE3 from Texas Instruments is a precision programmable shunt voltage reference IC with 0.5% initial tolerance at 25°C, adjustable output from 2.495 V to 36 V, and operation across −40°C to 125°C. It delivers 0.2 Ω typical dynamic impedance, 1–100 mA sink-current capability, and low 6 mV max temperature drift (C-temp grade), serving as a high-stability Zener diode replacement in feedback loops of isolated DC/DC converters and AC/DC power supplies.
For engineers reviewing the TL431BCLPE3 datasheet, TL431BCLPE3 pinout, TL431BCLPE3 application, or TL431BCLPE3 equivalent, this page provides verified electrical specifications, thermal performance data, stability boundary conditions, real-world application configurations, and validated alternative parts for industrial power design, server PSU feedback, and servo drive regulation.
Technical Context
The TL431BCLPE3 implements a three-terminal adjustable shunt regulator architecture with an internal error amplifier, reference voltage source, and output transistor. Its sharp turn-on characteristic and active output stage enable precise regulation without external compensation in most applications.
It operates as a two-input comparator driving a cathode-sink output: the REF pin senses voltage relative to ANODE, and the CATHODE sinks current to maintain VREF = 2.495 V ±0.5% at 25°C. The device requires ≥0.4 mA minimum cathode current for regulation and exhibits <0.5 Ω dynamic impedance up to 1 kHz.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±0.5% at 25°C - sets precise feedback threshold for power supply error amplifiers |
| Temperature Range | −40°C to 125°C - qualified for automotive-grade and industrial embedded power systems |
| Dynamic Impedance | 0.2 Ω typical - ensures stable loop response and minimal output voltage perturbation under load transients |
| Sink Current Range | 1 mA to 100 mA - supports direct interface with optocoupler LEDs and discrete transistor drivers |
| Output Noise | Low broadband noise - enables clean feedback in high-PSRR isolated SMPS designs |
| Temp Drift (VI(dev)) | ≤14 mV over full range - guarantees ≤0.056%/°C average coefficient for tight regulation across temperature |
| Min Cathode Current | 0.4 mA - defines lowest usable bias for reliable regulation in low-power standby modes |
Pinout & Package
TL431BCLPE3 is supplied in the TO-92 (LPE3) package - a through-hole, 3-pin plastic case with 0.1" lead spacing and body dimensions of 4.7 mm × 3.8 mm × 9.2 mm. Pin 1 is CATHODE, Pin 2 is ANODE, Pin 3 is REFERENCE (REF).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Current sink output | Connects to primary-side optocoupler LED or series resistor; carries full regulation current |
| ANODE (Pin 2) | Common reference node | Typically tied to system ground or return path; serves as voltage reference point for REF input |
| REF (Pin 3) | Threshold sense input | Monitors voltage divider output; triggers regulation when VREF ≥ 2.495 V relative to ANODE |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% Initial Accuracy (B Grade) | Reduces need for post-manufacturing trimming in high-volume AC/DC adapters and server PSUs |
| Adjustable Output (2.495 V to 36 V) | Enables single BOM part to support multiple output voltages via external resistor network |
| 0.2 Ω Dynamic Impedance | Minimizes output voltage deviation during fast load steps - critical for telecom and industrial SMPS |
| −40°C to 125°C Operation | Validated for under-hood automotive modules and high-ambient industrial motor drives |
| Low Reference Input Current (2–4 µA) | Permits use of high-value feedback resistors, reducing power loss and thermal drift in precision supplies |
Applications
| Rack Server Power Supply | Industrial AC/DC Converter |
|---|---|
|
Use Scenario: Secondary-side voltage regulation in isolated 48 V/12 V telecom rectifiers with optocoupler feedback. IC Role / Device Role / Timing Role: Shunt reference providing precise 2.495 V threshold to control optocoupler LED current and regulate primary-side PWM duty cycle. Use Value: Enables ±1% output accuracy over line/load/temperature without trimming, meeting IEC 62368-1 safety requirements. |
Use Scenario: Feedback reference in 3 kW industrial AC/DC front-end with wide input (85–265 VAC) and 24 V/48 V outputs. IC Role / Device Role / Timing Role: Adjustable shunt regulator setting error amplifier reference point for dual-output flyback controller. Use Value: Supports single-part design across multiple output voltages using resistor scaling, reducing BOM count and qualification effort. |
| AC Inverter Drive | Servo Drive Control Module |
|
Use Scenario: Auxiliary rail regulation for gate driver ICs and microcontroller power in 10–30 HP variable-frequency drives. IC Role / Device Role / Timing Role: Precision shunt reference stabilizing isolated 15 V auxiliary supply feeding isolated gate drivers and analog sensing circuits. Use Value: Maintains regulation stability across −40°C to 125°C ambient, ensuring gate drive integrity during thermal cycling in motor enclosures. |
Use Scenario: Feedback reference for ±15 V analog supply in closed-loop servo amplifier PCBs used in CNC motion control. IC Role / Device Role / Timing Role: High-stability reference establishing accurate offset and gain calibration points for op-amp-based current/voltage feedback paths. Use Value: 14 mV max temp drift ensures <0.1% gain error over operating range, preserving position accuracy in high-resolution encoder systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDBZR | SOT-23-3 surface-mount package; identical electrical specs but different thermal resistance (RθJA = 206°C/W vs 52°C/W for LPE3) | Preferred for space-constrained PCBs; requires thermal pad design for >50 mA continuous operation | Select TL431BIDBZR only when board area is limited and thermal management can be assured. |
| TL431BQDBZR | Same SOT-23-3 package as TL431BIDBZR but Q-temp grade (−40°C to 125°C); identical accuracy and drift | Offers same reliability as TL431BCLPE3 in extended temperature environments but with lower thermal mass | Choose TL431BQDBZR for new SMT designs requiring automotive AEC-Q100 alignment and compact footprint. |
Compared with TL431BCLPE3, TL431BIDBZR trades through-hole mechanical robustness and superior thermal dissipation for smaller size, while TL431BQDBZR matches its temperature range in a surface-mount form factor - both require layout-level thermal validation where >30 mA average cathode current is expected.
Availability
TL431BCLPE3 is available at Aetrix Electronics and suitable for rack server power supplies, industrial AC/DC converters, and servo drive control modules requiring stable component supply with long-term lifecycle continuity.
Supply support for TL431BCLPE3 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 technologies, with decades of expertise in precision reference and power control ICs.
The TL431 product line was designed specifically for high-accuracy, low-drift voltage regulation in isolated switching power supplies, offering Zener-replacement functionality with programmable output and enhanced thermal stability.
FAQ
What is the reference voltage tolerance of TL431BCLPE3 at 25°C?
The TL431BCLPE3 has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a nominal VREF of 2.495 V with a guaranteed range of 2.483 V to 2.507 V. This B-grade accuracy eliminates the need for manual calibration in high-volume power supply manufacturing and is confirmed in Section 6.11 of the TI SLVS543S datasheet.
Can TL431BCLPE3 operate in automotive under-hood environments?
Yes, TL431BCLPE3 is rated for operation from −40°C to 125°C and is qualified for automotive under-hood use. Its maximum temperature drift of 14 mV over that range (VI(dev)) and stable dynamic impedance ensure reliable regulation in engine control units and battery management auxiliary supplies where ambient temperatures exceed 105°C.
What is the minimum cathode current required for regulation in TL431BCLPE3?
The TL431BCLPE3 requires a minimum cathode current of 0.4 mA to maintain regulation, as specified in Sections 6.11–6.13 of the datasheet. This value is consistent across all B-grade variants (C/I/Q temp ranges) and enables stable operation in low-power standby modes of AC/DC adapters and industrial controllers.
How does the dynamic impedance of TL431BCLPE3 affect power supply stability?
The TL431BCLPE3 exhibits 0.2 Ω typical dynamic impedance below 1 kHz, which directly limits output voltage variation under fast load transients. This low impedance ensures predictable loop gain in optocoupler-coupled feedback networks and prevents instability caused by phase shift in high-bandwidth SMPS designs.
Is TL431BCLPE3 pin-compatible with other TL431 variants in TO-92 packages?
Yes, TL431BCLPE3 uses the standard TO-92 pinout (CATHODE–ANODE–REF) and is mechanically and electrically compatible with all TL431xCLPE3 variants. No PCB changes are required when upgrading from A-grade or standard-grade TO-92 devices, provided the tighter 0.5% tolerance meets system accuracy requirements.
TL431BCLPE3 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:
- ±0.5%
- 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
TL431BCLPE3 FAQ
1.How can I place an order for TL431BCLPE3 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431BCLPE3 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 TL431BCLPE3 reliable?
The price and inventory of TL431BCLPE3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431BCLPE3 is usually 5 days.
3.What payment methods are accepted for TL431BCLPE3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431BCLPE3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431BCLPE3?
TL431BCLPE3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431BCLPE3 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 TL431BCLPE3?
For technical support, including TL431BCLPE3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431BCLPE3 requirements.
6.How does Aetrix verify that TL431BCLPE3 is sourced from the original manufacturer or authorized distributors?
All TL431BCLPE3 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 TL431BCLPE3 meets industry standards.
7.What is the process for return or replacement of TL431BCLPE3?
All TL431BCLPE3 units undergo pre-shipment inspection (PSI). If there is an issue with TL431BCLPE3, 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 TL431BCLPE3 part is unused and in its original packaging.
Return procedure for TL431BCLPE3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431BCLPE3 Tags
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TL431AIDBZR
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TL431BQDBZR
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AZ431LBNTR-G1
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LM4040DIM3X-2.5/NOPB
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AZ431LANTR-G1
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